GB2136802A - Carbapenem process - Google Patents

Abstract

Disclosed is a new and more efficient process for producing carbapenem antibiotic derivatives having a 2- substituent of the general formula S-A-R<14> wherein A represents cyclopentylene, cyclohexylene or C2- C6 alkylene optionally substituted by one or more C1-C4 alkyl groups and R<14> represents a quaternized nitrogen-containing aromatic or non-aromatic heterocycle attached to A through a quaternary nitrogen atom. The carbapenems produced by this process are of the formula <IMAGE> R<8> being hydrogen and R<1> being hydrogen or one of various defined organic groups or R<1> and R<8> together completing a ring and R<2> being hydrogen, an anion or a protecting group. The starting materials are of the formula <IMAGE> and H-S-A-R<14> L being a leaving group and R<2> being a protecting group.

Description

SPECIFICATION Carbapenem process The present invention is directed to a new process for the preparation of carbapenum derivatives having a 2-substituent of the formula -S-A-R14 wherein A represents cyclopentylene, cyclohexylene or C2-C6 alkylene optionally substituted by one or more C1-C4 alkyl groups and R14 represents a quaternized nitrogen-containing aromatic or nonaromatic heterocycle attached to A through a quaternary nitrogen atom.

The carbapenem derivatives prepared by the process ofthe present invention are disclosed and claimed by my colleagues Choung U. Kim and Peter F. Misco, Jr., in U.S. Patent Applications Serial Nos.

366,910,471,379 and 389,652 filed, respectively, April 9,1982, March 8,1983 and June 1982; the entire disclosure of each of these applications is incorporated herein by reference.

U.S. Application 366,910 and its continuation-inpart U.S. Application Serial No.471,379, filed March 8, 1983, which continuation-in-part corresponds to West German published PatentApplication 3,312,533, disclose preparation of carbapenem anti biotics oftheformula

wherein R8 is hydrogen and R1 is selected from the group consisting of hydrogen; substituted and unsubstituted: alkyl, alkenyl and alkynyl, having from 1-10 carbon atoms; cycloalkyl and cycloalkylalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in the alkyl moieties; phenyl; aralkyl, aralkenyl, and aralkynyl wherein the aryl moiety is phenyl and the aliphatic portion has 1-6 carbon atoms; heteroaryl, heteroaralkyl, heterocyclyl and heterocyclylal kyl wherein the hereto atom or atoms in the above-named heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen orsulfur atoms and the alkyl moieties associated with said heterocyclic moieties have 1-6 carbon atoms; wherein the substituent or substituents relative to the above-named radicals are selected from the group consisting of C1-C6 alkyl optionally substituted by amino, halo, hydroxy or carboxy halo

wherein, relative to the above-named substituents, the groups R3 and R4 are independently selected from hydrogen; alkyl, alkenyl and alkynyl, having from 1-10 carbon atoms; cycloalkyl, cycloalkylalkyl and alkylcycloalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in the alkyl moities; phenyl; aralkyl, aralkenyl and aralkynyl wherein the aryl moiety is phenyl and the aliphatic portion has 1-6 carbon atoms; and heteroaryl, heteroaralkyl, heterocyclyl and heterocyclylalkyl wherein the hetero atom or atoms in the abovenamed heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moieties associated with said heterocyclic moieties have 1-6 carbon atoms, or R3 and R4takentogetherwiththe nitrogen to which at least one is attached may form a 5- or 6-membered nitrogen-containing heterocyclic ring; R9 is as defined for R3 exceptthat it may not be hydrogen; or wherein R1 and R8takentogetherrepresentC2-C10 alkylidene or C2-C10 alkylidene substituted by hydroxy; A is cyclopentylene, cyclohexylene orC2-C6 alkylene optionally substituted by one or more cl-C4 alkyl groups;R2 is hydrogen, an anionic charge or a conventional readily removable carboxyl protecting group, providing that when R2 is hydrogen or a protecting group, there is also present a counter anion; and

Formulae in the printed specification were reproduced from drawings submitted after the date of filing, in accordance with Rule 20(14) of the Patents Rules 1982.

This print takes account of replacement documents submitted after the date of filing to enable -the application to comply with the formal requirements of the Patents Rules 1982.

represents a substituted or unsubstituted mono-, bi or polycyclic aromatic heterocyclic radical containing at least one nitrogen in the ring and attached to A through a ring nitrogen,therebyforming a quater naryammonium group; and pharmaceuticaily acceptable slats thereof by the process shown in the following reaction scheme:

Application 389,652 and its continuation-in-part application 499,690filed June 7,1983 disclose preparation of carbapenem antibiotics ofthe formula

wherein R8 is hydrogen and R1 is selected from the group consisting of hydrogen; substituted and unsubstituted: alkyl, alkenyl and alkynyl, having from 1-10 carbon atoms; cycloalkyl and cycloalkylalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in the alkyl moieties; phenyl; aralkyl, aralkenyl and aralkynyl wherein the aryl moiety is phenyl and the aliphatic portion has 1-6 carbon atoms; heteroaryl, heteroaralkyl, heterocyclyl and heterocyclylalkyl wherein the heteroatom or atoms in the above-named heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moieties associated with said heterncyclic moieties have 1-6 carbon atoms; wherein the substituent or substituents relative to the above-named radicals are independently selected from the group consisting of C1-C6 alkyl optionally substituted by amino, halo, hydroxyorcarboxyl halo

wherein, relative to the above-named su bstituents, the groups R3 and R4 are independently selected from hydrogen; alkyl, alkenyl and alkynyl, having from 1-10 carbon atoms; cycloalkyl, cycloalkylalkyl and alkylcycloalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in the alkyl moieties; phenyl; aralkyl, aralkenyl and aralkynyl wherein the aryl moiety is phenyl and the aliphatic portion has 1-6 carbon atoms; and heteroaryl, heteroaralkyl, heterocyclyl and heterocyclylalkyl wherein the hetero atom or atoms in the abovenamed heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moieties associated with said heterocyclic moieties have 1-6 carbon atoms, or R3 and R4taken together with the nitrogen to which at least one is attached may form a 5- or 6- membered nitrogen-containing heterocyclic ring; R9 is as defined for R3 exceptthat it may not be hydrogen; or wherein R' and R8 taken together represent C2-C10 alkylidene or C2-C10 alkylidene substituted by hydroxy; R5 is selected from the group consisting of substituted and unsubstituted: alkyl, alkenyl and alkynyl, having from 1-10 carbon atoms; cycloalkyl and cycloalkylalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in the alkyl moieties; phenyl; aralkyl, aralkenyl and aralkynyl wherein the aryl moiety is phenyl and the aliphatic portion has 1-6 carbon atoms; heteroaryl, heteroaralkyl, heterocyclyl and heterocyclylalkyl wherein the hetero atom or atoms in the above-named heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moieties associated with said heterocyclic moieties have 1 -6 carbon atoms; wherein the above-named R5 radicals are optionally substituted by 1-3 substituents independently selected from: C-C6 alkyl optionally substituted by amino,fluoro, chloro, carboxyl, hydroxy or carbamoyl; fluoro, chloro or bromo; -OR3; -OCO2R3;-OCOR3; -OCONR3R4; -OSO2R3; -oxo; -NR3R4; R3CONR4-; -N R3Co2R4; -NR3CONR3R4; -N R3SO2R4; -SR3; 0 -S-R9; 0 0 -S-R9 -So3R3; -C02R3; -CONR3R4; -CN;;or phenyl optionally substituted by 1 -3fluoro, chloro, bromo, C1-C6 alkyl, -OR3, -NR3R4, -S03R3, -C02R3 or -CONR3R4,wherein R3, R4 and R9 in such R5 substituents are as defined above; or R5 may represent a divalent phenylene or C1-C4 alkylene group joined to the

ring so as to form a bridged polycyclic group; A is cyclopentylene, or cyclohexylene or C2-C6 alkylene optionally substituted by one or more C1-C4 alkyl groups;R2 is hydrogen, an anionic charge or a conventional readily removable carboxyl protecting group, providing that when R2is hydrogen ora protecting group, there is also present a counter ion; and

represents a substituted or unsubstituted mono-, bior polycyclic non-aromatic heterocyclic radical containing at least one nitrogen in the ring and attached toAthrough a ring nitrogen, thereby forming a quaternary ammonium group; and pharmaceutically acceptable salts thereof, by the process shown in the following reaction scheme:

To elaborate on the prior art scheme, starting material Ill is reacted in an inertorganicsolventwith diphenyl chlorophosphate in the presence of a base to give intermediate IV.Intermediate IV is then reacted with a mercaptan reagent of the formula HS-A-OH in an inert organic solvent and in the presence of a base to give intermediate V. Intermediate V is then acylated with methanesulfonyl chloride in an inert organic solvent and in the presence of base to give intermediate VI which is reacted with a source of iodide ions in an inert organic solvent to give intermediate II. Intermediate II is reacted with the desired amine in an inert organic solvent and in the presence of silver ion to produce the quaternized productl'Aor l'B which maythen be de-blockedto give the corresponding de-blocked carbapenem of Formula IA or IB.

The above-described process has several disadvantages. Thus, for example, the process involves several steps which advantageously could be re duced in number. The overall reaction yield is also quite low and the quaternization step is performed on the entire carbapenem compound. It would be desirable to have a new process for producing compounds of Formula IA or IB which (1) involves fewer reaction steps, (2) gives higheryields, (3) allows the quaternized amine to beformedfirst and then attachedtothe carbapenem nucleus at a later stage in the synthesis and (4) can be used to more easily form quaternary amine products with a wide varietyofamines,i.e. amineswithsterichindrance and those with low pKvalues.

The present invention provides a novel process for preparation of carbapenem derivatives of the formula

wherein R8 is hydrogen and R1 is selected from the group consisting of hydrogen; substituted and unsubstituted: alkyl, alkenyl and alkynyl, having from 1-10 carbon atoms; cycloalkyl and cycloalkylalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in th alkyl moieties; phenyl; aralkyl, aralkenyl and aralkynyl wherein the aryl moiety is phenyl and the aliphatic portion has 1-6 carbon atoms; heteroaryl, heteroaralkyl, heterocyclyl and heterocyclylalkyl wherein the hetero-atom or atoms in the above-named heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moieties associated with said heterocyclic moieties have 1-6 carbon atoms; wherein the substituent or substi- tuents relative to the above-named radicals are selected from the group consisting of C1-C6 alkyl optionally substituted by amino, halo, hydroxy or carboxyl halo

wherein, relative to the above-mentioned su bstituents, the groups R3 and R4 are independently selected from hydrogen; alkyl, alkenyl and alkynyl, having from 1-10 carbon atoms; cycloalkyl, cycloalkylalkyl and alkylcycloalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in the alkyl moieties; phenyl; aralkyl, aralkenyl and aralkynyl wherein the aryl moiety is phenyl and the aliphatic portion has 1-6 carbon atoms; and heteroaryl, heteroaralkyl, heterocyclyl and heterocyclylalkyl wherein the hetero atom or atoms in the abovenamed heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moieties associated with said heterocyclic moieties have 1-6 carbon atoms, or and R4taken together with the nitrogen to which at least one is attached mayform a5-or6-membered nitrogen-containing heterocyclic ring; R9 is as defined for R3 exceptthat it may not be hydrogen; or wherein R1 and R8 taken together represent CrCio alkylidene or C2-C10 alkylidene substituted by hydroxy; A is cyclopentylene, cyclohexylene or C2-C6 alkylene optionally substituted by one or more cl-C4 alkyl groups;R2 is hydrogen, an anionic charge ora conventional readily removable carboxyl protecting group, providingthatwhen R2 is hydrogen ora protecting group, there is also present a counter anion; and R14 is a quaternized nitrogen-containing aromatic or non-aromatic heterocycle attached to A through a ring nitrogen,therebyforming a quaternaryammonium group, ora pharmaceutically acceptable saltthereof, which process comprises reacting an intermediate oftheformula

wherein R1 and R8 are as defined above, R2 is a conventional, ready removable carboxyl protecting group and Lisaconventional leaving group,with a thiol compound oftheformula HS-A-R'4 Xe VII wereinA and B14 are as defined above and Xe is a counter anion, in an inert solvent and in the presence of base, to produce a carbapenem product of the formula

wherein R1, R8, R2, A, R14 and Xe are as defined above and, if desired, removing the carboxyl protecting group R2,to givethecorresponding de-blocked compound offormula I, or a pharmaceutically acceptable salt thereof.

Also provided bythe present invention are in termediates af Formula VII and processes for preparing such intermediates.

Thecarbapenem compounds of Formula I are potent antibacterial agents or intermediates useful in the preparation of such agents.

The compounds of general Formula I above contain thecabapenem nucleus

and maythus be named as 1 - carba - 2 - penem -3 carboxylic acid derivatives. Alternatively, the compounds may be considered to have the basic structure

and named as 7 - oxo - 1 - azabicyclo(3.2.0)hept - 2 ene - carboxylic acid derivatives. While the present invention includes compounds wherein the relative stereochemistry of the 5,6-protons is cis as well as trans, the preferred compounds have the 5R,6S (trans) stereochemistry as in the caseofthienamycin.

The compounds of Formula I may be unsubstituted in the 6-position or substituted by substituent groups previously disclosed for other carbapenem derivatives. More specifically R8 may be hydrogen and R may be hydrogen or a non-hydrogen substituent disclosed, for example, in European PatentApplication 38,869 (see definition of R6). Alternatively, R8 and R1 taken together may be Etc10 alkylidene or C2-C10 alkylidene substituted for example, by hydroxy.

To elaborate on the definitions for R1 and R8: (a) The aliphatic "alkyl", "alkenyl" and "alkynyl" groups may be striaght or branched chain having 1-10 carbon atoms; preferred are 1-6, most preferably 1 -4, carbon groups; when part of another substituent, e.g. as in cycloalkylalkyl, or heteroaralkyl oraralkenyl,thealkyl, alkenyl and alkynyl group preferably contains 1-6, most preferably 1-4, carbon atoms.

(b) "heteroaryl" includes mono-, bi- and polycyclic aromatic heterocyclic groups containing 1-40, N or S atoms; preferred are 5- or 6- membered heterocyclic rings such asthienyl,furyl,thiadiazolyl,oxadiazolyl, triazolyl, isothiazolyl, thiazolyl, imidazolyl, isoxazolyl, tetrazolyl, oxazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyrrolyl, pyrazolyl, etc.

(c) "heterocyclyl" includes mono-, bi- and polycy- clic saturated or unsaturated non-aromatic heter ocyclicgroupscontaining 1-40, N orS atoms; preferred are 5- or 6-membered heterocyclic rings such as morpholinyl, piperazinyl, piperidyl, pyrazo linyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, pyr rolinyl, pyrrolidinyl, etc.

(d) "halo" includes chloro, bromo, fluoro and iodo and is preferably chloro or bromo.

Theterm "conventional readily removable car boxyl protecting group" refers to a known ester group which has been employed to block a carboxyl group during the chemical reaction steps described below and which can be removed, if desired, by methods which do not result in any appreciable destruction ofthe remaining portion ofthe molecule, e.g. by chemical or enzymatic hydrolysis, treatment with chemical reducing agents under mild conditions, irradiation with ultraviolet light or catalytic hydrogenation. Examples of such ester protecting groups include benzhydryl, p-nitrobenzyl, 2-naph- thylmethyl, allyl, benzyl, trichloroethyl, silyl such as trimethylsilyl, phenacyl, p-methoxybenzyl, acetonyl, o-nitrobenzyl, 4-pyridylmethyl and C1 -C6 alkyl such as methyl, ethyl ort-butyl.Included within such protecting groups are those which are hydrolyzed under physiological conditions such as pivaloyloxymethyl, acetoxymethyl, phthalidyl, indanyl and methoxymethyl. Particularly advantageous carboxyl protecting groups are p-nitrobenzyl which may be readily removed by catalytic hydrogenolysis and allyl which can be removed by Pd(P3)4-catalyzed reaction.

The pharmaceutically acceptable salts referred to above include the nontoxic acid addition salts, e.g.

salts with mineral acids such as hydrochloric, hydrobromic, hydroiodic, phosphoric, sulfuric, etc. and salts with organic acids such as maleic, acetic, citric, succinic, benzoic, tartaric, fumaric, mandelic, ascorbic, lactic, gluconic and malic. Compounds of Formula I in the form of acid addition salts may be written as

R2=H or protecting group where Xe represents the acid anion. The counter anion Xe may be selected so asto provide pharmaceutically acceptable salts for therapeutic administration but, in the case of intermediate compounds of Formula I Xe may also be a toxic anion. In such a case the ion can be subsequently removed or substituted by a pharmaceutically acceptable anion to form active end productfortherapeutic use.When acidic or basic groups are present in the R1 group or on the quaternized R14 radical, the present invention may also include suitable base or acid salts of these functional groups, e.g. acid addition salts in the case of a basic group and metal salts (e.g. sodium, potassium, calcium and aluminum),the ammonium salt and salts with nontoxic amines (e.g. trialkylamines, procaine, dibenzylamine, l-ephenamine, N benzyl - '3 - phenethylamine, N,N' - dibenzylethylenediamine, etc.) in the case of an acidic group.

Compounds of Formula I wherein R2 is hydrogen, an anionic charge or a physiologically hydrolyzable estergrouptogetherwith pharmaceutically acceptable salts thereof are useful as antibacterial agents.

The remaining compounds of Formula I arevaluable intermediates which can be converted into the above-mentioned biologically active compounds.

A preferred embodiment of the present invention comprises compounds of Formula Wherein R8 is hydrogen and R1 is hydrogen, CH3CH2-

Among this subclass, the preferred compounds are those in which R' is

most preferably compounds having the absolute configuration 5R, 6S, 8R.

Another preferred embodiment comprises compounds of Formula I in which R1 and R8taken together form an alkylidene radical of the formula

The alkylene or cycloalkylene radical A in the compounds of Formula I may be cyclopentylene cyclohexylene

or CrC6 alkylene optionally substituted by one or more C-C4alkyl substituents. Preferred A substituents are cyclopentylene, cyclohexylene or alkylene of the formula

in which R10, R11, R'2and R13 are each independently hydrogen or C1-C4 alkyl.A preferred embodiment comprisesthose compounds of Formula I in which substituentA is-CH2CH,

In the case of certain compounds of Formula I having a cycloalkylene or branched alkylene A substituent, one or more additional assymmetric carbon atoms may be created which result in formation of diastereoisomers. The present invention includes mixtures of such diastereoisomers as welll as the individual purified diastereoisomers.

The quaternized Ra4substituent may be an optionally substituted mono-, bi- or polycyclic aroma tic or non-aromatic heterocylic radical containing at least one nitrogen in the ring and attached to A through a ring nitrogen, thereby forming a quater nary ammonium group.

One preferred class of R14 substituents may be represented bythe general formula

which is meantto define a substituted or unsubsti tuted mono-, bi-orpolycyclicheteroaryl radical containing at least one nitrogen in the ring and attached to a carbon atom ofsubstituentAthrough a ring nitrogen, thereby forming a quaternary ammonium group.The heteroaryl radical may be optionally substituted by such substituents as C1 -C4 alkyl, C1-C4 alkyl substituted by hydroxy, amino, carboxy or halo, C3-C6 cycloalkyl, C1-C4 alkoxy, C1-C4 alkylthio, amino, C1-C4 alkylamino, di(C1-C4 alkyl)amino, halo, C1-C4 alkanoylamino, C1-C4alkanoyloxy, carboxy,

alkyl, hydroxy, amidino, guanidino, trifluoromethyl, phenyl, phenyl substituted by one, two or three amino, halo, hydroxyl,trifluoromethyl, C1-C4 alkyl or C1-C4 alkoxy groups, heteroaryl and heteroaralkyl in which the hetero atom or atoms in the above-named heterocyclic moieties are selected from the group consisting of 1-40, N orS atoms and the alkyl moiety associated with heteroaralkyl has 1-6 carbon atoms.

The heteroaryl radical attached to substituentA is preferably a 5- or 6- membered aromatic heterocyclic radical containing a quaternized nitrogen atom (which is directly bonded to a carbon atom of the alkylene or cycloalkylene radical) and, optionally, one or more additional hetero atoms selected from 0, N or S.While, in general, any heteroaryl radical bonded to Avia a quaternized nitrogen atom is found to produce biologically active carbapenem derivatives, a preferred embodiment comprises compounds in which

represents a radical selected from the group consist ingof

wherein R5, R6 and R7 are independently selected from hydrogen; C1-C4alkyl; C1-C4alkyl substituted by hydroxy, amino, carboxy or halo; C3-C6 cycloalkyl; C1-C4 alkoxy; C1-C4 alkylthio; amino; C1-C4alkylamino; di(C1-C4 alkyl)amino; halo; C1-C4 alkanoylamino; C1 -C4 alkanoyloxy; carboxy;

alkyl; hydroxy, amidino; guanidino; trifluoromethyl; phenyl; phenyl substituted by one, two orthree amino, halo, hydroxyl,trifluoromethyl, C1-C4 alkyl orC1-C4alkoxygroups; and heteroaryl and heteroaralkyl in which the hetero atom or atoms in the above-named heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moiety associated with said heteroaralkyl moiety has 1-6 carbon atoms; or wherein two of R5, R6 or R7 taken together may be a fused saturated carbocyclic ring, a fused aromatic carbocyclic ring, a fused saturated heterocyclic ring or a fused heteroarorfiatic ring,

optionally substituted on a carbon atom by one or more substituents independently selected from C1-C4 alkyl; C1-C4 alkyl substituted by hydroxy, amino, carboxy or halogen; C3-C6 cycloalkyl; C1-C4 alkoxy; C1-C4alkylthio; amino; C1-C4alkylamino; di(C1-C4 alkyl)amino; halo;C1-C4 alkanoylamino; C-C4alka- noyloxy; carboxy;

alkyl; hydroxy; amidino; guanidino; trifluoromethyl; phenyl; phenyl substituted by one, two orthree amino, halo, hydroxyl, trifluoromethyl, C1-C4 alkyl orC1-C4 alkoxy groups; and heteroaryl or heteroaralkyl in which the heteroatom or atoms in the above-named heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moiety associated with said heteroaralkyl moiety has 1-6 carbon atoms, or optionally substituted so as to form a fused carbocyclic or heterocyclic ring;

optionallysubstituted on a carbon atom by one or more substituents independently selected from C1-C4 alkyl; C1-C4alkyl substituted by hydroxy, amino, carboxy or halogen;C3-C6 cycloalkyl; C1-C4 alkoxy; C1-C4alkylthio; amino; C1-C4alkylamino; di(C1-C4 alkyl)amino; halo; C1-C4alkanoylamino; C1-C4alka- noyloxy; carboxy;

alkyl; hydroxy; amidino; guanidino; trifluorometnyl; pnenyl; pnenyi suostitutea oyone,two orthree amino, halo, hydroxyl,trifluoromethyl, Ca-C4 alkyl orC,-C4alkoxy groups; and heteroaryl or heteroaralkyl in which the hetero atom or atoms in the above-named heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moiety associated with said heteroaralkyl moiety has 1-6 carbon atoms, or optionally substituted so as to form a fused carbocy clicorheterocyclic ring;

optionally substituted on a carbon atom by one or more substituents indendently selected from C1-C4 alkyl; C1-C4alkyl substituted by hydroxy, amino, carboxy or halogen; C3-C6 cycloalkyl; C1-C4 alkoxy; C1-C4 alkylthio; amino; C1-C4 alkylamino; di(C-C4 alkyl)amino; halo; C1-C4alkanoylamino ;C1-C4alkanoyloxy; carboxy;

alkyl; hydroxy; amidino; quanidino; trifluoromethyl; phenyl; phenyl substituted by one, two orthree amino, halo, hydroxyl,trifluoromethyl, C1-C4 alkyl orC1-C4alkoxygroups; and heteroaryl or heteroaralkyl in which the hetero atom or atoms in the above-named heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moiety associated with said heteroaralkyl moiety has 1-6 carbon atoms, or optionally substituted so as to form a fused carbocyclic or heterocyclic ring;;

wherein Xis O, S or NR in which R is C1-C4 alkyl or phenyl, said radical being optionally substituted on a carbon atom by one or more substituents indepen dently selected from C1-C4 alkyl; C1-C4 alkyl substituted by hydroxy, amino, carboxy or halogen; C3-C6 cycloalkyl; C1-C4 alkoxy; C1-C4 alkylthio; amino; C1-C4 alkylamino; di (C1-C4alkyl) amino; halo; C1-C4 alkanoylamino;C1-C4 alkanoyloxy; carboxy;

alkyl; hydroxy; amidino; guanidino; trifluoromethyl; phenyl; phenyl substituted by one, two orthree amino, halo, hydroxyl, trifluoromethyl, C1-C4 alkyl orC1-C4 alkoxy groups; and heteroaryl or heteroaralkyl in which the hetero atom or atoms in the above-named heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and yhr alkyl moiety associated with said heteroaralkyl moiety has 1-6 carbon atoms, or optionally substituted so as to form a fused carbocyclic or heterocyclic ring;

wherein Xis O, S orNR in which R isC1-C4alkyl or phenyl, said radical being optionally substituted on a carbon atom by one or more substituents independently selected from C1-C4 alkyl; C1-C4 alkyl su bstituted by hydroxy, amino, carboxy or halogen;C3-C6 cycloalkyl; C1-C4 alkoxy; C1-C4 alkylthio; amino; C1-C4 alkylamino; di (C-C4alkyl) amino; halo; Ca-C4 alkanoylamino; C1-C4alkanoyloxy; carboxy;

alkyl; hydroxy; amidino; guanidino; trifluoromethyl; phenyl; phenyl substituted by one, two orth ree amino, halo, hydroxyl, trifluoromethyl, C1-C4alkyl or C1-C4 alkoxy groups ; and heteroaryl or heteroaralkyl in which the hetero atom or atoms in the above-named heterocyclic moieties are selected fromthegroupconsisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moiety associated with said heteroaralkyl moiety has 1-6 carbon atoms; and

wherein R is C1-C4 alkyl or phenyl, said radical being optionally substituted on the carbon atom by a substituent selected from C1-C4 alkyl; C1-C4 alkyl substituted by hydroxy; amino, carboxy or halogen; C3-C8 cycloalkyl; C1-C4 alkoxy; C1-C4 alkylthio ; amino; C1-C4alkylamino; di (C1-C4alkyl) amino; C-C4 alkanoylamino; carboxy;

alkyl; hydroxy; amidino; guanidino; trifluoromethyl; phenyl, phenyl substituted by one, two ofthree amino, halo, hydroxyl,trifluoromethyl, C1-C4alkyl or cl-C4 alkoxygroups; and heteroaryl or heteroaralkyl in which the hetero atom or atoms in the above-named heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moiety associated with said heteroaralkyl moiety has 1-6 carbon atoms.

Within the above subclass, the preferred com pounds are those in which substituentA is

or (b) R8 is hydrogen and R' represents hydrogen, CH3CH ,

Particularly preferred are the compounds wherein R8 is hydrogen and R1 is

preferably compounds having the absolute conflguration 5R,6S,8R.

A particularly preferred embodiment ofthe present invention comprises preparation of compounds wherein

represents a radical of the formula

in which R5, R6 and R7 are independently selected fromthe group consisting of hydrogen, C1-C4alkyl, C1-C4 alkoxy, C1-C4 alkyl substituted by a hydroxy group, C1-C4 alkylthio, amino, carboxy and carbamoyl.Within this subclass, the preferred compounds are those wherein substituent A is-CH2CH2-,

and wherein either (a) R1 and R8 taken together represent

or (b) R8 is hydrogen and R1 represents hydrogen, CHsCH2-,

Particularly preferred are the compounds wherein R8 is hydrogen and R1 is

preferably compounds having the absolute configuration 5R,6S,8R.

A most preferred embodiment ofthe present invention comprises preparation of compounds wherein

represents a radical ofthe formula

in which R5, R6 and R7 are independently selected from the group consisting of hydrogen, C1-C4 alkyl, C1-C4 ; alkoxy, C1-C4 alkyl substituted by a hydroxy group, C1-C4 alkylthio and amino.Within this subclass, the preferred compounds are those wherein substituentAis

and wherein either (a) R1 and R taken together represent

or (b) R8 is hydrogen and R1 represents hydrogen, CH3CH,

Particularly preferred are the compounds wherein R8 is hydrogen and R1 is

preferably compou nds having the absolute configuration 5R, 6S, 8R.

Another preferred em bodiment of the present invention comprises preparation of compounds wherein

represents a radical of the formula

Within this subclass, the preferred compounds are those wherein substituentA is

and wherein either (a) R1 and B8 taken together represent

or (b) R8 is hydrogen and R' represents hydrogen, CH3CH2-,

Particularly preferred are the compounds wherein R8 is hydrogen and R1 is

preferably compounds having the absolute configuration 5R, 6S, 8R.

Another preferred embodiment of the present invention comprises preparation of compounds wherein

represents a pyridinium radical. Within this subclass, the preferredcompoundsarethosewherein substi tuent A is

taken together represent

or (b) R8 is hydrogen and R1 represents hydrogen, CK3CK2-,

Particularly preferred are the compounds wherein R8 is hydrogen and R1 is

preferably compounds having the absolute configuration 5R, 6S, 8R.

A most preferred embodiment of the present invention comprises the preparation of compounds ofthe formula

wherein

represents

R or S diastereoisomers R,R, or S,S diastereoisomers at two assymmetric carbons of the cyclohexyl group and R2 is hydrogen, an anionic charge or a conven tional readily removable carboxyl protecting group, providing thatwhen R2 is hydrogen or a protecting group, there is also present a counter anion, and pharmaceutically acceptable acid addition salts thereof.

Another preferred class of quaternized R14 substi tuents may be represented by the general formula

in which R16 is selected from the group consisting of substituted and unsubstituted: alkyl, alkenyl and alkynyl, having from 1-10 carbon atoms; cycloalkyl and cycloalkylalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in the alkyl moieties; phenyl; aralkyl, aralkenyl and aralkynyl wherein the aryl moiety is phenyl and the aliphatic portion has 1-6 carbon atoms; heteroaryl, heteroaralkyl, heterocyclyl and heterocyclylalkyl wherein the hetero atom or atoms in the above-named heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moieties associated with said heterocyclic moieties have 1-6 carbon atoms; wherein the above-named R16 radicals are optionally substituted by 1-3 su bstituents independently selected from: C,-C6 alkyl optionally substituted by amino, fluoro, chloro, carboxyl, hydroxy or carbamoyl; fluoro, chloro or bromo; -OR3; -OCO2R ; -OCOR ; -OCONR R4 ; -OSO2R3; -oxo ; -N R3R4; R CONR4 ; -NR3Co2R4; -NR3CONR3R4; -NR3So2R4; -SR3;

-SO R ; -Co2R3; -CONR R4 ; -CN;or phenyl optionally substituted by 1-3 fluoro, chloro, bromo, cl-C6 alkyl, - OR3, -NR R4, -SO3R ,-CO2R3 or -CONB3R4, wherein R3, R4and R9 in such R5 substituents are as defined above; or R16 may represent a divalent phenylene or C1-C4 alkylene group joined to the

ring so as to form a bridged polycyclic group and

represents a substituted or unsubstituted mono-, bior polycyclic non-aromatic (which may be fused to another aromatic or non-aromatic ring) heterocyclic radical containing at least one nitrogen in the ring and attached to Athrough a ring nitrogen, thereby forming a quaternary ammonium group.The heterocyclic radical may be saturated or unsaturated (with 1-2 double bonds) and may contain up to two additional hetero atoms in addition to the quaternary nitrogen, such additional hetero atoms being selected from O,S(O)m, N,NR15 or NR17R18 wherein m is 0,1 or 2, R75 is hydrogen, optionally substituted C1 6 alkyl or optionally substituted phenyl and R17 and R18 are each independently optionally substituted C1-C6 alkyl or optionally substituted phenyl.

In a preferred embodiment

represents a non-aromatic 4-7 membered, preferably S-or 6-membered, N-containing heterocyclic ring containing 0-2 double bonds and 0-2 additional hetero-atoms selected from 0, S(O)m,N, NR75 or NRa7Rr8wherein m is 1 or2, R15 is hydrogen, C1-C6 alky optionally substituted by 1-2 substituents independently selected from-OR R4, -CO2R , oxo phenyl, fluoro, chloro, bromo, -SO3R and-CONR R4 or phenyl optionally substituted by 1-3 substituents independently selected from C1-C6 alkyl, -OR3, -N R3R4, fluoro, chloro, bromo, -SO3R , - CO2R and -CONR R4 and R17 and R18 are each independently C1-C6 alkyl optionally substituted by 1-2 substituents independently selected from-OR , -NR R4, -CO2R , oxo, phenyl,fluoro, chloro, bromo, - SO3R and -CONR3R4 or phenyl optionally substituted by 1-3 substituents independently selected from C1 -C6 alkyl, -OR , - NR R4, fluoro, chloro, bromo, - SO3R , -CO2R and -CONR R4, wherein R3 and R4 in such heterocyclic NR15 or NR17 R18 groups are as defined above in connection with the R16 substituent.In such preferred embodiment the

ring may be optionally substituted by 1-3 substituents independently selected from (a) C1-C6 alkyl optionally substituted by 1-2 substituents independently selected from fluoro, chloro, bromo, - OR , - OCOR , - OCONR R4, oxo ; - NR R4, -NR COR4, -NR CONR R4, -NR SO2R4, -SR -SO3R , - CO2R , - CO2R and -CONR R4 ; (b) CrC6 alkenyl optionally substituted by 1-2 substituents independently selected from fluoro, chloro, bromo, -OR , - OCOR , - OCONR R4, oxo, -NR R4, -NR COR4, -NR CONR R4, - NR SO2R4, -SR , -SO3R , - CO2R and - CONR R4 ; (c) C2-C6 alkynyl optionally substituted by 1-2 substituents independently selected from fluoro, chloro, bromo, - OR , - OCOR , - OCONR R4, oxo, -NR R4, - NR COR4, -NR CONR R4, - NR SO2R4, -SR , - SO3R , - CO2R , - CO2R and - CONR R4 ;; (d) C3-C6cycloalkyl optionally substituted by 1-2 substituents independently selected from fluoro, chlorom, bromo, - OR , - OCOR , - OCONR R4, oxo, -NR R4, -NR COR4, -NR3CO N R3R4, -NR3So2R4, -SR3, -So3R3, -Co2R3 and -CO NR3R4t (e) cycloalkylalkyl having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in the alkyl moiety, optionally substituted by 1-2 substituents independently selected from fluoro, chloro, bromo, -OR , - OCOR , - OCO N R3R4, oxo,-NB3B4, -N R3CoR4 -NR CONR R4, - NB SO2R4, -SR , - SO3R , - CO2R and-CONR3R4; ; (f) heteroarylwhereinthe hetero atom or atoms are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms, optionally substituted by 1-2 substituents independently selected from fluoro, chloro, bromo, -OR , - OCOR , -OCONR R4, oxo, -NR R4, - NR COR4, - NR CONR R4, - NR SO2R4, -SR3,-SO3R3,-CO2R3and-CONR3R4; preferred heteroaryl radicals are 5- or 6-membered aromatic heterocyclic rings; (g) heteroaralkyl wherein the hetero atom or atoms are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moiety has 1-6 carbon atoms, optionally substituted by 1-2 substituents independently selected from fluoro, chloro, bromo, -OR3, -OCOR3, -OCON R3R4, oxo, -NR R4, - NR COR4, - NR CONR R4, -NR SO2R4, -SR3, -S03B3, -CO2B3 and -CO N R3R4; preferred heteroaralkyl are those in which the heteroaryl radical is a 5- or 6-membered aromatic heterocyclic ring and the alkyl moiety has 1-2 carbon atoms; (h) heterocyclyl wherein the hetero atom or atoms are selected from the group consisting of 1-4 oxygen, nitrogen orsulfur atoms, optionally substituted by 1-2 substituents independently selected from fluoro, chloro, bromo,-OR3, -OCOR3, -OCON R3R3, oxo, -NB3B3, -N R3COR4, -N R CONR R4, -N B3SO2R4, -S B3, -So3R3, -CO2R3 and -CONR3R4; preferred heterocyclyl are 5- or 6-membered saturated or unsaturated rings; (i) heterocyclyalkyl wherein the hetero atom or atoms are selectedfrom the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moiety has 1-6 carbon atoms, optionally substituted by 1-2 substituents i ndependenly selected from fluoro, chloro, bromo, -OR , - OCOR , - OCONR R4, oxo, -NR R4, - NR COR4, - NR CONR R4, - NR SO2R4, -SR ,-SO3R ,-CO2R and-CONR R4 ; preferred heterocycylalkyl are those in which the heterocyclyl moiety is a 5- or 6-membered saturated or unsaturated ring; (j) fluoro, chloro or bromo; (k) -OR3; (1) -OCO2R ; (m) -OCOR3; (n) -OCONR3R4; (o) -OSo2R3; (P) oxo; (q) -NR3R4; (r) R3CONR4-; (s) -NR3Co2R4; (t) -IR3CoNR3R4; (u) -NR3So2R3; (v) -SR3;

(y) -SO3R3; (z) -co2R3; (aa) -CONR3R4; (bb) -CN; or (cc) phenyl optionally substituted by 1-3 fluoro, chloro, bromo, C1-C6 alkyl, - OR , - NR R4, -SO3R , CO2R or-CONR R4 The R3, R4 and R9 substituents mentioned above are as defined in connection with substituent R'.

The ring as defined above is a non-aromatic heterocycle group.This ring, however, may be fused to another ring which may be a saturated or unsaturated carbocyclic ring, preferably a C4-C7 carbocyclic ring, a phenyl ring, a 4-7 membered heterocyclic (saturated or unsaturated) ring containing 1-3 hetero atoms selected from O,N, S(O)rn, NR15 or NR17R18 or a 5-6 membered heteroaromatic ring containing 1-3 hetero atoms selected 0, (O)rn, N, NR15 or NR17R16 in which m, R15, R17 and R18 are as defined above.

The R16 substituent of the non-aromatic R14 radical may be either (a) an optionally substituted cl-C6 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C3-C6 cycloalkyl, C3-C6 cycloalkyl-C,-C6 alkyl, phenyl, phenyl-C-C6 alkyl, phenyl-C2-C6 alkenyl, phenyl-C2-C6 alkynyl, heteroaryl, heteroaralkyl in which the alkyl moiety has 1-6 carbon atoms, hererocyclyl or heterocyclyalkyl in which the alkyl moiety has 1-6 carbon atom or (b) a divalent phenylene or C1-C4 alkylene group joined to the

ring so as to form a bridged ring polycyclic group, e.g.

a quinuclidine group. The heteroaryl (or heteroaryl portion of heteroaralkyl) substituent may be a mono-, bi- or polycyclic aromatic heterocyclic group containing 1-40, N or S atoms ; preferred are 5- or 6-membered heterocyclic rings such as thienyl, furyl, thiadiazolyl, oxadiazolyl, triazo lyl, isothiazolyl, thiazolyl, imidazolyl, isoxazolyl, tetrazolyl, oxazolyl, pyridyl, pyrazinyl, pyrimidinyl, puridazinyl, pyrrolyl and pyrazolyl. The heterocyclyl (or heterocyclyl portion of heterocyclylalkyl) substituent may be a mono-, bi- or polycyclic saturated or unsaturated non-aromatic heterocyclic group containing 1-4 O,N or S atoms; preferred are 5- or 6-membered heterocyclic rings such as morpholinyl, piperazinyl, piperidyl, pyrazolinyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, pyrrolinyl and pyrrolidinyl.

In the case where the R16 substituent is an alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, phenyl, phenylalkyl, phenylalkenyl, phenylalkynyl, heter oaryl, heteroaralkyl, heterocyclyl or heterocyclylalkyl group, such groups may be optionally substituted by 1 -3 substituents independently selected from:: (a) C1-C6 alkyl optionally substituted by, preferably 1-3, amino,fluoro, chloro, carboxyl, hydroxyor carbamoyl groups; (b) fluoro, chloro or bormo; (c) -OR3; (d) -OCO2R3; (e) -OCOR3; (f) -OCONR3R4; (g) -OSO2R ; lhk -oxo, (i) -NB3B4; (i) -OSO2R ; (k) -NR CO2R4 ; (l) -NR CONR R4 ; (m) -NR3So2R4; (n) -SR3; (o) -SOR9; (p) -SO2B9; (q) -So3R3; (r) -Co2R3; (s) -CONR3R4; (t) -CN;;or (u) phenyl optionally substituted by 1 -3 substi- tuents independently selected from fluoro, chloro, bromo, C,-C6 alkyl,-OR3, -NR R4, - SO3R , - CO2R or -CONR3R4, wherein, relative to the above-named R16 substituents, the groups R3 and R4 are independently selected from hydrogen; alkyl, alkenyl and alkynyl, 1-10 carbon atoms; cycloalkyl, cycloalkylalkyl and alkylcycloalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in the alkyl moieties; phenyl; aralkyl, aralkenyl and aralkynyl wherein the aryl moiety is phenyl and the aliphatic portion has 1-6 carbon atoms; and heteroaryl, heteroaralkyl, heterocyclyl and heterocyclylalkyl wherein the heteroaryl and heterocyclyl group or portion of a group is as defined above for R'6 and the alkyl moieties associated with said heterocyclic moieties have 1-6 carbon atoms; or R3 and R4taken togetherwith the nitrogen to which at least one is attached may forum a 5- or 6-membered nitrogencontaining heterocyclic (as defined above for R5) ring; and R9 is as defined above for R3 except that it may not be hydrogen. A most preferred R16 substi tuent is C1-C6 alkyl, especially methyl.

In the case where R16 is a divalent phenylene or C1-C6 alkylene group, such group is bonded to another atom ofthe

ring so as to form a bridged polycyclic ring, e.g. a quaternized quinuclidine ring oftheformula

A particularly preferred embodiment of the present invention comprises preparation of compounds of Formula I wherein

wherein Y is hydrogen, C,-C6 alkyl, hydroxy, -SC-C6 alkyl, carboxyl, carbamoyl, chloro, bromo, iodo, fluoro or phenyl.Within this subclass, the preferred compounds arethosewherein A is

-(CH2)n-in which n is 2,3 or 4, more preferably those in which A is-CH2CK2-, -CH2CH2CH2-,

and most preferablythose in which A is-CH2CH2-, and wherein either (a) R1 and R8 taken together represent

or (b) R8 is hydrogen and R1 represents hydrogen, CH3CHr,

Particularly preferred are the compounds wherein d8 is hydrogen and R' is

especially compounds having the absolute configuration 5R, 6S, 8R.

A still more preferred embodiment of the present invention comprises preparation of compounds of Formula I wherein

represents

Within this preferred subclass, the preferred compounds are those wherein A is

-(CH2)n- in which A is 2,3 or 4, @ more preferably those in which A is-CH2CH2-, -CH2CH2CH2-,

and most preferably those in which A is-CH2CH2-, and wherein either (a) R' and B8 taken together represent

or (b) R8 is hydrogen and R' represents hydrogen, CH3CH2-,

Particularly preferred are the compounds wherein R8 is hydrogen and R' is

especially compounds having the absolute configuration 5R, 6S, 8R.

As still more preferred embodiment of the present invention comprises preparation of compounds of Formula I wherein

represents

in which Y is hydrogen, cl-C6 alkyl, hydroxy, -S-C-C6 alkyl, carboxyl, carbamoyl, chloro, bromo, iodo, fluoro or phenyl. Within this preferred subclass, the preferred compounds are those wherein Ais-(CH2)nin which n is 2,3 or4, most preferably those in which Ais-CH2-CH2-and wherein eitehr (a) R and R8 taken together represent

or (b) R8 is hydrogen and R1 represents hydrogen, CH3CH2-,

Particularly preferred arethe compounds wherein R8 is hydrogen and R1 is # especially compounds having the absolute configuration 5R,6S,8R.

A most preferred embodiment of the present invention comprises preparation of compounds of Formula I wherein

represents

Within this preferred subclass, the preferred compounds are those wherein A is-(CH2)n- in which n is 2,3 or4, most preferablythose in which A is -CH2CH2-andwherein either (a) R1 and R8taken together represent

or (b) R8 is hydrogen and R1 represents hydrogen, CH3CH2-,

Particularly preferred are the compounds wherein R8 is hydrogen and R1 is

especially compounds having the absolute configuration 5R, 6S, 8R.

A most preferred embodiment ofthe present invention comprises preparation of the compounds oftheformula

and R2 is hydrogen, an anionic charge or a conventional readily removable carboxyl protecting group, providing thatwhen R2 is hydrogen ora protecting group, there is also present a counter ion, and pharmaceutically acceptable acid addition salts thereof.

Itwill be appreciated that certain products within the scope offormula I may be formed as optical isomers as well as epimeric mixtures thereof. Itis intended that the present invention include within its scope all such optical isomers and epimeric mixtures.

For example, when the 6-substituent is hydroxyethyl, such substituent may be in eitherthe R or S configuration and the resulting isomers as well as epimeric mixtures thereof are encompassed by the present invention.

The process of the present invention utiiizes the intermediate of the formula

which has been disclosed, for example, in European Patent Application 38,869 and which may be prepared bythe general methods described therein. L represents a conventional leaving group (defined as "X" in European Patent Application 38,869) such as chloro, bromo, iodo, benzenesulfonyloxy, p-toluenesulfonyloxy, p-nitrobenzenesulfonyloxy, methanesulfonyloxy, trifluoromethanesu Ifonyloxy, diphenoxyphosphinyloxyordi(trichloroethoxy)phosphinyloxy. The preferred leaving group is diphenoxyphosphinyloxy.Intermediates of Formula IV are generally formed in situ by reacting an intermediate oftheformula

Ill wherein R', R8 and R' are as defined above with a suitable acylating agent R -L. The preferred intermediate IV where L is diphenoxyphosphinyloxy may be prepared by reacting keto ester Ill in an inert organic solvent such as methylene chloride, acetonitrile or dimethylformarnide with about an equimolar amountofdiphenyl chlorophosphate in the presence of a base such as diisopropylethylamine, triethyla mine, 4-dimethylaminopyridine orthe like ata temperature of from about -20 C to +40 C, most preferably at about 0 C. Intermediate IV may be isolated, if desired, but is conveniently used as the starting material forthe process ofthe present invention without isolation or purification.

In the present process, carbapenem intermediate IV is reacted with a quaternary aminethiol compound of the formula HS-A-R14 X8 VII wherein A is cyclopentylene, cyclohexylene or C2-C8 alkylene optionally substituted by one or more C1-C4 alkyl groups, most preferably cyclopentylene, cyc lohexylene or

in which R10, R11, B12 and R13 are each independently hydrogen or C1-C4 alkyl, X8 is a counter anion associated with a strong acid such as Cl-, Br-, CH3SO3-, CF3SO3- or

R14 is a quaternized nitrogen-containing aromatic or non-aromatic heterocycle as defined above.The reaction is carried out in an inert solvent such as acetonitrile, acetonitrile-dimethylformamide, tet rahydrofu ran, tetrahydrofuran-H2O, acetonitrile-H20 or acetone in the presence of base. The nature of the base is not critical. Best results, however, have been obtained when a non-nucleophilictertiary amine base such as diisopropylethylamine, 1,8 diazabicyclo[5.4.0]undec - 7 - ene, 1,5 - diazabicyclo[4.3.0]non-5-ene or tri(C1 C4)alkylamine such as triethylamine, tributylamine or tripopylamine is employed.Reaction of intermediate IVthiol VA may be carried out over a wide temperature range, e.g. - 15 C up to room temperature, but is preferably done at a temperature in the range of from about-15 C to-+15 C, most preferably at around 0 C.

The carbapenem product produced by reaction of the quaternary amine thiof Vll with intermediate IV will have a counter anion associated with it [e.g.

(C6H5O)2PO28, Cl8 or the anion associated with the quaternarythiol] which may atthis stage be substituted buy a different counter anion, e.g. one which is more pharmaceutically acceptable, by conventional procedures. Alternatively, the counter anion may be removed during the subsequent de-blocking step.

Where the quaternized carbapenem compound and counter anion form an insoluble product, the product maycrystallize out as it isformed and be collected pure by filtration.

Following formation ofthe desired carbapenem product, the carboxyl protecting group R' of Compound I' may be optionally removed by conventional procedures such as solvolysis, chemical reduction or hydrogenation. Where a protecting group such as p-nitrobenzyl, benzyl, benzhydryl or 2 - naphthylmethyl is used which can be removed by catalytic hydrogenation, intermediate I' in a suitablesolvent such as dioxane-water-ethanol, tetrahydrofurandiethylether - buffer, tetrahydrofuran - aqueous dipotassium hydrogen phosphate - isopropanol or the like may be treated under a hydrogen pressure of from 1 to 4 atmospheres in the presence of a hydrogenation catalystsuch as palladium on charcoal, palladium hydroxide, platinum oxide orthe like at a temperature of from Oto 50 Cforfrom about 0.24.

to 4 hours. When R' is a group such as o-nitrobenzyl, photolysi may also be used fordeblocking. Protecting groups such as 2,2,2 -trichloroethyl may be removed by mild zinc reduction. The allyl protecting group may be removed by using a catalyst comprising a mixture of a palladium compound andtriphenyl phosphine in a suitable aprotiesolvent such as tetrahydrofuran, methylene chloride or diethyl ether. Similarly, other conventional carboxyl protecting groups may be removed by methods known to those skilled in the art. Finally, as mentioned above, compounds of formula I' where R' is a physiologically hydrolyzable ester such as acetoxymethyl, phthalidyl, indanyl, pivaloyloxymethyl, methoxymethyl, etc may be administered directly to the host without de-blocking since such esters are hydrolyzed in vivo under physiological conditions.

lt vvill be understood that were the R and/or R8 substitutent or the quaternized nucleophile R74 attached to su bstituent A contai n a functional group which might interfere with the intended course of reaction, such group may be protected by a conventional blocking group and then subsequently deblocked to regenerate the desired functional group.

Suitable blocking groups and procedures for introducing and removing such groups are well known to those skilled in the art.

As in the case of other p-lactam antibiotics, compounds of general Formula I may be converted by known procedures to pharmaceutically acceptable salts which, for purposes of the present invention, are substantially equivalent to the non-salted compounds. Thus, for example, one may dissolve a compound of Formula I wherein R2 is an anionic charge in a suitable inert solvent and then add an equivalent of a pharmaceutically acceptable acid. The desired acid addition salt may be recovered by conventional procedures, e.g. solvent precipitation, lyophilization, etc. Where other basic or acidic functional groups are present in the compound of Formula I, pharmaceutically acceptable base addition salts and acid addition salts may be similarly prepared by known methods.

Acompound of Formula I where R2 is hydrogen or an anionic charge, or a pharmaceutically acceptable saltthereof may also be converted by conventional procedures to a corresponding compound where R2 is a physiologically hydrolyzable ester group, or a compound of Formula I wherein R2 is a conventional carboxyl protecting group may be converted to the corresponding compound where R2 is hydrogen, an anionic charge or a physiologicaily hydrolyzable ester group, or a pharmaceutically acceptable salt thereof.

Certain ofthe thiol intermediates of Formula VII may be prepared, for example, by reacting a sulfide of the formula

wherein R10, R11, R12 and B13 are each independently hydrogen or C1-C4aikyl with a heteroaromatic amine (as defined above) of the formula

or a non-aromatic heterocyciic amine (as defined above) oftheformula

and a strong acid. The reaction may be carried out in the presence or absence of an inertorganic solvent which is preferably a non-polar organic solvent such as methylene chloride, benzene, xylene, toluene or the like. Where the amine and sulfide reagents are liquids orwhere a solid amine is soluble in a liquid sulfide reagent, it is preferred to carry out the reaction without use of an additional solvent.

The particular strong acid used in the reaction is not critical and may be, for example, such strong inorganic or organic acids as hydrochloric, hydrobromic, methanesulfonic, p-toluenesulfonic,trifluoromethanesulfonic, etc.

Formation of the quaternary amine thiol intermediate VII may be carried out at a temperature in the range of from about -20 C to about 1 00'C. Preferred temperatures are generally in the range of about 50-70"C.

The sulfide reagent, aromatic amine and acid are preferably employed so that the sulfide and acid are used in approximately equimolar amounts with the amine being used in excess, e.g. two to three moles of amine per mole of sulfide or acid.

The quaternary aminethiol intermediate will have a counter anion associated with it which will be determined by the particular acid employed. It is, of course, possible to substitute atthis point a different counter anion by conventional procedures for use in the subsequent reaction with carbapenem intermediate IV.

The carbapenem derivatives of general Formula I wherein R2 is hydrogen, an anionic charge or a physiologically hydrolyzable carboxyl protecting group, orthe pharmaceutically acceptable salts thereof, are potent antibiotics active against various gram-positive and gram-negative bacteria and they may be used, for example, as animal feed additives for promotion of growth as preservatives in food, as bactericides in industrial applications, for example in waterbased paint and in the white water of paper millsto inhibit the growth of harmful bacteria and as disinfectants for destroying or inhibiting the growth of harmful bacteria on medical and dental equipment. They are especially useful, however, in the treatment of infectious disease in humans and other animals caused by gram-positive or gram-negative bacteria.

The pharmaceutically active compounds provided by the novel process ofthis invention may be used alone orformulated as pharmaceutical compositions comprising, in addition to the active carbapenem ingredient, a pharmaceutically acceptable carrier or diluent. The compounds may be administered by a variety of means; those of principal interest include: orally, topically or parenterally (intravenous or intramuscular injection). The pharmaceutical compositions may be in solid form such as capsules, tablets, powders, etc., or in a liquid form such as solutions, suspensions or emulsions. Compositions for injection, the preferred route of delivery, may be prepared in unit dose form in ampulesorin multidose containers and may contain formulatory agents such as suspending, stabilizing and dispersing agents.The compositions may be in ready to use form or in powder form for reconstitution at the time of delivery with a suitable vehicle such as sterile water.

The dosageto be administered dependsto a large extent on the particular compound being used, the particularcomposition formulated, the route of administration,thenatureandcondition ofthe host and the particularsitus and organism being treated.

Selection of the particular preferred dosage and route of application, then, is leftto the discretion of the therapist. In general, however, the compounds may be administered parenterally or orally to mammalian hosts in an amount of from about 5 to 200 mg/kg/day.

Administration is generally carried out in divided doses, e.g. three to fourtimes a day.

The following examples illustrate but do not limit the scope of the present invention.

Example 1 Preparation of 3-(2-(1-pyridinium)ethylthio)-6&alpha;-(1 - (R) - hydroxyethyl) - 7- oxo - 1- azabicyclo(3.2.O) hep-2-ene-2-carboxylate A. 1- (2 - mercaptoethyl)pyridinium methanesulfonate

To a suspension of pyridinium methanesulfonate in pyridine prepared by the dropwise addition of methanesulfonic acid (1.95 mL, 0.03 mol) to pyridine (8.0 mL. 0.099 mol) with cooling, was added ethylene sulfide (1.96 mL, 0.033 mol). The resulting mixture was stirred at 55 C for 16 hand concentrated under reduced pressure to a thick syrup which was mixed with a few mLof water. The solution was poured on top of a column (40 x 16 cm) of -bondapak C-18 which was eluted with water.Lyophylization of the appropriate fractions gave a colorless syrup 6.5 g (91%), ir (film) Vmax : 2300-2600 (br, SH), 1635 (pyridinium), 1490,1200 (sulfonate), 1068, 1060, 1045, 791, 780 cm-1, Hmr (DMSO-d6) # : 2.32 (3H,s, CH3SO3), 2.61, 2.70, 2.73, 2.82 (1H, B part of A2B system, SH), 3.07 (2H, m [with D2O, 3.08 (2H, t, J=6.5 Hz)], CH2S,), 4.76 (2H, t, J=6.5Hz, CH2N+), 8.19 (2H, m, Hm of pyridinium), 8.6 (1H, m. Ho of pyridinium), 9.08 (2H, dd, J=6.8 Hz, J=1 ,4Hz, Ho of pyridinium), uv (H2O) Anal: 206 (s5230), 258 (s3760) mp.

METHOD A B. 1- (2 - mercaptoethyl)pyridinium chloride

An queous solution of crude 1 - (2 - mercaptoethyl) pyridinium methanesulfonate (9.4 g, 0.04 mol) was poured on top of column (2.5 x 41 cm) of permutit tS-1 Cl-. The column was eluted with water at a rate of 0.5 15 mL per min and the appropriatefractionswere combined and lyophylized giving yellowish syrup 7.0 g (100%) which was used as itwasforthe next step, Hmr (D2O) 5:3.22 (sH, m, CH2S), 4.88 (m, CH2N+), 8.18 (2H, m; Hm of pyridinium), 8.7(1 H, m, Mp of pyridinium), 9.0 ppm (2H, m, of pyridinium).

METHOD B

To a precooled (ice bath) pyridine (5.6 mL, 70 mmol) was added pyridine hydrochloride (4.05 g, 35 mmol) and ethylene sulfide (2.1 mL, 35 mmol). The mixturewas heated at 650C and stirred for 75 min to give two phases system. The lighter phase was removed. The remaining oil was washed with ether (5 x 10 mL) and pumped under high vacuum to give the title compound (90-100%) which was used as such for the next step.

C. Paranitrobenzyl-3-[2-(1-pyridinium)ethylthio) 6&alpha;-[1-(R)-hydroxyethyl]-7-oxo-1- azabicyclo(3.2.0)hept-2-ene-2-carboxylate chloride

A solution of p-nitrobenzyl 6&alpha;- [1 - (R) - hydroxy ethyl] - 3,7 - dioxo - 1 - azabicyclo(3.2.0)heptane - 2 carboxylate (6.09 g, 17.5 mmol) in acetonitrile (20 mL) was cooled to +5 Cundera nitrogen atmosphere and treated successively with diisopropylethylamine (3.65 mL, 21.0 mmol) and diphenyl chlorophosphate (4.34 mL, 21.0 mmol).The resulting mixture was stirred for 30 min at 5 C, cooled to -50C and treated successively with a solution of crude 1 - (2 mercaptoethyl)pyridinium chloride (4.3 g, 24 mmol) in N,N-dimethylformamide (1.0 mL) and dropwise with diisopropyiethylamine (3.65 mL, 21.0 mmol).

The reaction mixture was stirred at 0 C for 1 hr, cooled to -300C and stirred for 15 min. more. The solid was filtered off and washed with cold (-30 C) acetonitrile 5.77 g (65%), ir (nujol) vrnax 3300 (OH), 1775 (C=O of -lactam), 1690 (C=O of PNB ester), 1630 (pyridi nium), 1605 (phenyl of PNB ester), ISiS (NO2), 1335 cm 1 (NO2), 1Hmr(DMSO-d6) # : 1.17 (3H, d, J=6.1 Hz, CH3CHOH), 3.2-3.75 (SH, H-4, H-6, CH2S), 3.75-4.5 (2H, H-5, CH3CHOH), 4.92 (2H, brt, J=6.5 HJz, CH2N+), 5.18 (1H, d, J=4.9Hz, OH), 5.37 (center of ABq.Ja,b=14.2 Hz, CH2 of PNB), 7.69 (2H, d J=8.7 Hz, # Ho of PNB),8.24 (d, J=8.7 Hz,Hm of PNB), 8.0-8.4 (4H, # Hm of PN B, Hm of pyridinium), 8.66(1 H, m, m, Hp ofpyridinium), 9.17 (2H, brd, J=5.5 Hz, Ho of pyridinium). The filtrate and washing were combined and diluted with ether (150 mL). The supernatantwas decanted and the gum was dissolved in water {40 mL) containing enough aceto nitrileto have a solution which was poured on top of a column (3x10 cm) of bondapak C-18. The column was eluted with 10% acetonitrile-90 water (150 mL) L) and 50% acetonitrile-50% water (100 mL) mixtures. The appropriate fractions were combined and lyophylized after the acetonitrile has been removed undervacuum giving a yellowish powder.

An NMR of it showed the presence of the title compound mixed with some p-nitrobenzyl 3 - [2 - (1 pyridinium) ethylthio]-6c-[1-(R)-hydroxytethyol]-7oxo - 1 - azabicyclo(3.2.0)hept - 2 - ene - 2 - carboxylate diphenylphosphate (2:11).The powder was dissolved in water (minimum amount) and passed through a column (1.5 x 21 cm) of permutit S-1 C1-with water.

Lyophlization of the appropriate fractions gave 1.8 g (20%) ofthe title compound.

D. Paranitrobenzyl3-[2-(1-pyridinium)ethylthio] 6&alpha;-[1-(R)-hydroxyethyl]-7-oxo-1- azabicylo(3.2. O)hept-2- ene - carboxylate dipheny Iphosphate.

A solution of p-nitrobenzyl 6&alpha;- [1 - (R) - hydroxyethyl] - 3,7 - dioxo - 1 - azabicyclo(3.2.0)heptane - 2 carboxylate (0.174 g, 0.50 mmol) in acetonitrile (2 mL) was cooled to 0 C under a nitrogen atmosphere and treated successively with diisopropylethylamine (0.105 mL, 0.60 mmol) and diphenyl chlorophosphate (0.124 mL, 0.60 mmol). The resulting solution was stirred for 30 min at 0 C and treated successively with a solution of 1 - (2 - mercaptoethyl)pyridinium methanesulfonate (0.170 g, 0.72 mmol) in acetonitrile (0.6 mL) and diisopropylethylamine (0.105 mL, 0.60 mmol).The reaction mixture was stirred at 0 C for 15 min, diluted with cold (0 C) water (7 mL) and poured on top of a column (1.5 x 6.4 cm) of -bondapak C-18.

The column was eluted with a mixture of acetonitrile (20%-50%) In water (75%-50%). The appropriate fractions were combined and lyophylized afterthe acetonitrile has been removed undervacuum giving a yellowish powder 0.33 g (92%), ir (KBr) vmax:36003000 (OH), 1765 (C=O of ss-lactam), 1690 (C=O of PNB ester), 1625 (pyridinium), 1585 (phenyl), 1510 (NO2), 1330 (NO2), 88Scm1 (NO2), 1Hmr(DMSO-d6) 5:1.16 (3H, d, J=6.2 Hz, CH3CHOH), 4.87 (2H, brt, J=6.6 Hz, CH2S), 5.37 (center of ABq, Ja,b= 14.3 Hz, CH2 of PN B), 6.7-7.5 (phenyl), 7.68 (d, J=8.8 Hz, Ho of PNB), 8.23 (d, J=8.8 Hz, Hm of PNB), 8.0-8.3 (m, Hm of pyridinium), 8.4-8.8 (1H, Hp of pyridinium), 9.09 (2H, dd, J=6.7 Hz,J=1.3 Hz, Ho of pyridinium).

E. 3-[2- (1 -pyridinium)ethylthio]-6a -[i - (R)- hydroxyethyl]-7-oxo -1 -azabicyclo(3.2.0)hept-2- ene - 2 - carboxylate MethodA

To a solution of p-nitrobenzyl 3 - [2 - (1 pyridinium)ethylthio] - 6cs - [1 - (R) - hydroxyethylj - 7 - oxo - 1 - azabicyclo(3.2.0)hept - 2 - ene - carboxylate diphenylphosphate (0.16 g, 0.22 mmol) in wettet- rahydrofuran (10 mL) was added ether (10 mL), potassium phosphate monobasic-sodium hydroxide bufferpH 7.4(16 mL,0.05 M) and 10% palladium on charcoal (0.16g).The resulting mixture was hydrogenated under40 psi for 1 hat 25 C. The two phases were separated and the organic phase was extracted with water (2 x 3 mL).The aqueous solutions were combined, washed with ether (2x1 10 mL) and poured on top of a column (1.5x6.2 cm) of -bondpak C-18 after the traces of organic solvents have been removed under vacuum. Elution of the column with water gave after lyophylization ofthe appropriate fractions a yellowish powder 0.062 g (84%), ir ( KBr) vmax : 3700-3000 (OH), 1755 (C=O of ss-lactam), 1630 (pyridinium), 1590 cm-1 (carboxylate),1 Hmr (D2O): 1.22 (3H, d, J=6.4 Hz, CH3CHOH), 2.92 (d, J=9.1 Hz, H-4), 2.97 (d, J=9.1 Hz, H-4), 3.20 (dd, J=2.5 Hz, J=6.1 Hz, H-6), 3.44 (t, J=6.0 Hz, CH2S), 3.93 (dd, J=9.1 Hz, J=2.5 Hz, H-5) 4.82 (t, J=6.0 Hz, CH2N+), 8.04 (m, Hm of pyridinium), 8.5 (m, Hp of pyridinium), 8.82 (dd, J=3.2 Hz, J=1.1 Hz, Ho of pyridinium), uv (H2O) Anal: 259 (s5800), 296 (E7030) m p, t1/2 = 13.5 H (measured at a concentration of 10-4 M in phosphate buffer pH 7.4 at 36.8 C).

Method B

To a solution of p-nitrobenzyl 3 - [2 - (1 pyridinium) ethylthio]-6&alpha;-[1-(R)-hydroxyethyl]-7- oxo - 1 - azabicyclo(3.2.0)hept- 2 - ene - 2 - carboxylate chloride (5.77 g, 11.4 mmol) in potassium phosphate monobasic-sodium hydroxide buffer(170 mL, 0.2 M, pH 7.22) was added tetrahydrofuran (30 mL), ether (30 mL) and 10% palladium on charcoal (S.7g).The resulting mixture was hydrogenated at 220C under 40 psi for 1 hand filtered on a Celite pad. The pad was washed with water (2 x 15 mL). The filtrate and washingswere combined and diluted with ether (100 mL).The aqueous phase was separated, washed with ether (3 x 100 mL) and poured on top of a column (4.5 x 20 cm) of u-bondapak C-18 after the organic solvants have been removed undervacuum. Elution of the column with water followed by a mixture of 1% acetonitrile in water gave after lyophylization ofthe appropriate fractions 2.48 g (65% ) of the title compound as a yellowish powder. The analytical data were identical to those reported for the compound prepared in the method A.

Example 2 Preparation of 3- [2 - (1- (3,5 - dimethylpyridinium)ethylthiol]- 6&alpha;-[1-(R)- hydroxyethyl]- 7- oxo 1-azabicyclo(3.2.0)hept-2-ene-2-carboxylate

A. 1 - (2- mercaptoethyl)-3,5-dimethylpyridinium methanesulfonate

To a suspension of 3,5-lutidinium methanesulfon atein 3,5-lutidine prepared by the addition of methanesulfonic acid (0.65 mL, 0.010 mol) to cold 3,5-lutidine (2.51 mL, 0.022 mol) was added ethylene sulfide (0.655 mL, 0.011 mol). The resulting mixture was stirred under a nitrogen atmosphere at 55 C for 24 h, cooledto 23 C and diluted with water (5 mL) and ether (5 mL). The organic layer was separated and the aqueous solution was washed with ether (6 x 4 mL).

The traces of ehter were removed under vacuum and the solution was applied on top of a column (2.5 x 6.0 cm) of u-bondapak C-1 8. The column was eluted with water and lyophilization of the appropriate fractions gave a colourless syrup 2.4 g (91%); ir (film) vrnax: 2520 (SH), 1628 (pyridinium), 1600, 1495, 1325, 1305, 1283, 1200 (sulfonate), 1040, 938, 765, 680 cm-1 ; Hmr (DMSOd6)5: 2.31 (3H, S,CH3SO3-),2.47 (6H, s, CH3 on pyridinium), 2.57,2.66,2.69,2.78(1 H, B part of A2B system, SH), 3.06 (2H, m [with D2O added (2H, t, J=6.5 Hz)], CH2S), 4.65 (2H, t, J=6.5 Hz, CH2N+), 8.34(1 H, s, Hp of pyridinium), 8.79 (2H, s, Ho of pyridinium); uv (H2O) Anal: 271 (s4860) mu. Anal. calcd. for C10H17NO3S2.O.5H2O : C44.09, H 6.66, N 5.14, S 23.54; found: C44.26, H 6.49, N S.17,s 24.18.

B. Paranitrobenzyl3-[2- (1 - (3,5- dimethylpyridi- nium)) ethylthio]-6&alpha;-[1-(R)-hydroxyethyl]-7-oxo - 1 - azabicyclo(3.2. O)hept-2-ene-2- carboxylate diphenylphosphate

To a cold (0 C) ; solution of p - nitrobenzyl 65 - (1 - (R) - hydroxyethyl) - 3,7 - dioxo - 1 azabicyclo(3.2.0)heptane - 2 - carboxylate (0.523 9, 1.50 mmol) in acetonitrile (6.0 mL) kept under a nitrogen atmosphere was added diisopropylethyla mine (0.314 mL, 1.8 mmol) followed by diphenyl chlorophosphate (0.373, 1.8 mmol).The reaction mixture was stirred for 30 min and treated with a solution of 1 - (2 - mercaptoethyl) - 3, 5 - dimethylpyr idinium methanesulfonate (0.493 9, 1.87 mmol) in acetonitrile (1.9 mL) followed by diisopropylethyla mine (0.314 Ml, 1.8 mmol). The reaction mixture was stirred at 0 C for 1 hr diluted with cold (00C) water (26 mL) and poured on top of a column (7.0 x 3.5 cm) of -bondapak C-18.Elution ofthe column with 25-50% acetonitrile - 75-50% water mixture gave after lyophi- lization of the appropriate fractions 1.01g (90%) of the title compound as yellowish powder, ir (KBr)max : 3700-3100 (OH), 1778 (C=O of P - lactam), 1700 (C+O of PNB ester), 1635 (pyridinium), 1595 (phenyl), 1521 (NO2), 1335 (NO2), 859 cm-1 (NO2), 1Hmr (DMSOd6) # : 1.16 (3H, d J=6.1 Hz, CH3CHOH), 2.43 (s, Ch3 on pyridinium), 4.75 (2H, m, CH2N+), 5.38 (centerofABq, Ja, b=14.3 Hz, CH2 of PNB), 6.6-7.5 (1 (10H, m, phenyl), 7.70 (2H, d, J=8.7 Hz, Ho of PNB), 8.0.-8.S (3H, m, Hp of pyridinium, Hm of PNB), 8.82 (2H, s, Ho of pyridi nium), uv (H2O) #max : 270 (#11570), 306 (87343) mu. Anal. calcd. for C37H38N3O10SP.H2O : C 58.03, H 5.26, N5.48, S4.18 ; found: C57.98, H 5.05, N 5.22, S 4.34.

C. 3- [2- (1 - (3,5- dimethylpyridinium))ethylthio]- 6oc -[7-(R)-hydroxyethyl]-7-oxo- -1- azabicyclo(3.2.0)hept-2-ene-2-carboxylate

To a solution of p-nitrobenzyl 3-[(1-(3,5 dimethylpyridinium))ethylthio]-6&alpha;-[1-(R)- hydroxyethyl] -7 - oxo - 1 - azabicyclo(3.2.0)hept - 2 ene - 2 - carboxylate diphenylphosphate (0.600 g, 0.80 mmol) in wet tetrahydrofuran (36 mL) was added ether (36 mL), potassium phospate monobasic ) sodium hydroxide buffer (0.05M, pH 7.4,44 mL) and 10% palladium on charcoal (0.60 g). The resulting mixture was hydrogenated under 40 psi at 23 C for 1.25h. The organic (2 x 5 mL).Water layers were combined, filtered through a Celite pad, washed with ether (40 mL), pumped to eliminate traces of organic solvents and poured ontop of a column (2.5 x 10.0 cm) of -bondapak C-18. Elution of the column with water and lyophilization ofthe appropriate fractions gavethetitle compound 0.186 9 (64%) as a yellowish powder, ir (KBr) # max : 3700-3100 (OH), 1760 (C=O of - lactam), 1595 cm-1 (carboxylate), 1Hmr (D2O) 5: :1.21 (3H, d, J=6.3 Hz, CH3CHOH), 2.45 (6H, s, CH3 on pyridinium), 2.81 (d, J=9.2 Hz, H-4), 2.96 (d, J=9.2 Hz, H-4), 3.22 (dd, J=2.6 Hz, J=6.2 Hz, H-6), 3.40 (t, J=6.2 Hz, CH2S), 3.84 (dd, J=9.2 Hz, J=2.6 Hz, H-5), 4.15 (m, CH3CHOH), 4.71 (t, J=6.2 Hz, CH2N+), 8.21 (1H, s, Hp of pyridinium), 8.46 (2H, s, Ho of pyridinium), uv (H2O) #max : 279 (#8345), 296 (#7714)m, [&alpha;]D + 40.7 (c0.53, H2O), T1/2-16.9 h (measured at a concentration of 10-4M in phosphate buffer pH 7.4 at 36.8 C).

Example 3 Prearation of(5R, 6S) -3-[[2-hydroxymethylpyridi- nio) ethyl]thio]-6-[1-(R)-hydroxyethyl]-7-oxo-1azabicyclo[3.2.0]hept-2-ene-2-carboxylate

A. 3 - Hydroxymethyl - 1- (2 - metcaptoethyl)pyridinium trifluoro methanesulfonate

Trifluoromethanesulfonic acid (1.327 mL, 0.015 mol) was added dropwise to 3 - pyridinemethanol (2.91 m L, 0.030 mol), followed by ethylene sulfide (0.89 mL, 0.015 mol). The resulting homogeneous mixture was heated (oil bath) at 50-70 C under N2 for 20 h. The reaction mixture was then taken up in H2O (15 mL) and extracted with CH2Cl2 (5 x 5 mL). The acqueous phase was concentrated in vacuo and then applied to a C18 reverse-phase column.Elution with H2O followed by evaporation ofthe relevant fractions gave a pale yellow oil. This matrial was rechromatographed to give a nearly colourless oil. After drying in vacuo (P2O5) this afforded to the product (4.50 g, 94%) as a viscous oil. ir (film) #max : 3450 (s, OH), 2560 (w, SH) cm-1. Hmr (d6-acetone) # : 9.10-8.05 (m, 4H, aromatic), 5.01 (t, J=5.5 Hz, 2H, N-CH2), 4.93(s, 2H, -CH2OH), 4.43 (br S, 1H, -OH), 3.43-3.18 (m, 2H, S-CH2), 2.34-2.10 (m, 1 H, SH).

B. p - Nitrobenzyl (5R, 6S) - 3 - [2 - (3 - hydroxymethyl pyridinio)ethylthio]-6-[1-(R)-hydroxyethyl)-7oxo-1-azabicyclo[3.2.0]hept-2-ene-2carboxylate diphenylphosphate

To a solution of p - nitrobenzyl (5R, 6S)-6- [1 - (R) - hydroxyethyl] - 3,7 - dioxo - 1 - azabicyclo [3.2.0)heptane - 2 - carboxylate (0.174 g, 0.50 mmol) in 2 mL of dry acetonitrile was added diisopropylethylamine (0.096 mL, 0.55 mmol) atO C under N2. Diphenyl chlorophosphate (0.114 mL, 0.55 mmol was then added dropwise and the reaction was stirred at 0 C for 30 min.Asolution 3-hydroxymethy-1-(2mercaptoethyl) pyridinium trifluoromethanesulfonate (0.223 g, 0.70 mmol) in 0.50 mLof acetonitrile was then added, followed by diisopropylethylamine (0.122 mL, 0.70 mmol). After being kept at 0 C for 30 min the reaction mixture was concentrated in vacuo and the residual yellow gum was taken up in H2O (enough acetonitrile was added to aid in dissolving the gum). This solution was applied to a Cl8 reverse-phase column which was eluted with 15% acetonitrile- H2O.Lyophilization ofthe relevant fractions afforded the product (0.305 g, 81%) as a beige-coloured solid. ir (KBr) #max : 3420 (br, OH), 1775 (ss-lactam Co), 1695(-CO2PNB)cm-1 ; Hmr (d6 acetone) # : 9.44-7.72 (m, 8H, aromatic), 7.22-6.91 (m, 10H, diphenylphosphate), 5.53, 5.27 (ABq, J=14Hz, 2H, benzylic), 5.04 (t, J=7.4 Hz, 2H, N-CH2), 4.75(s, 2H, CH2OH), 4.5-3.1 (m, 8H), 1.21 (d, J=6.3 Hz, 3H, CHMe).

C. (5R, 6S)-3-[2-(3- hydroxymethylpyridinio)ethyl) thio]-6-[1-(R)-hydroxyethyl)-7-oxo-1-azabicylo [3.2.0]hept-2-ene-2-carboxylate

To a solution of p - nitrobenzyl (5R, 6S) - 3 - [2 - (3 hydroxymethylpyridinio)ethyl thio] - 6 - [1 - (R) hydroxyethyl] - 7 - oxo - 1 - azabicyclo [3.2.0] - hept - 2 ene - 2 - carboxylate diphenylphospate (0.145 g, 0.194 mmol) in 10 mL of THF containing 5 drops of H2O, was added 6.0 mL of phosphate buffer (0.05 M, pH 7.4), 0.1459 of 10% palladium-on-charcoal and 10 mLof ether. The mixturewas hydrogenated (Parr) at 40 psi for 1 hand then filtered through a pad of Celite.The filter cake was washed with a little H2O and ether and the aqueous phase was separated and extracted with ether (2x). The aqueous solution was then cooled at 0 C and the pH was adjusted to 7.0 with pH 7.4 buffer.

After removing residual volatiles in vacuo the aqueous solution was applied to a C18 reverse-phase column which was eluted with H2O. Lyophilization of the relevant fractions gave the product (36 mg, 51 %) as a light yellow solid. Further purification by reverse-phase hplc gave the pure product (31 mg, 41%) as a solid. ir(KBr) #max : 3300 (br, OH), 1755 (ss- lactam CO), 1590 (-CO2-)cm-1 ; Hnmr (D2O) # : 8.78-7.94 (m, 4H aromatic), 4.83 (t, J=6.0 Hz, 2H, N-CH2), 4.83(s, 2H, CH2OH), 4.16 (d of q, J=J'=6.2 Hz, 1 H, H-1 '), 3.98 (d, oft, J=9.1 Hz, J'=2.6 Hz, 1 H, H-5), 3.75-3.20 (m,3H), 3.20-2.65 (m, 2H), 1.22 (d, J=6.4 Hz, 3H, CHM) ; uv (H2O) #max : 294 (#7614), 266 (#6936) nm; t1/2 (ph 7.4, 36.80C) 14.0 h.

Example 4 Preparation of (5R,6S)-3-[2-(4-hydroxymethylpyridino)ethylthio] -6-[1-(R)-hydroxyethyl]-7-oxo-1azabicyclo[3.2.0]hept-2-ene-2-carboxylate

A. 4 - Hydroxymethyl - 7- (2 - mercaptoethyl)pyridi- nium trifluoromethanesulfonate

To a solution of 4-pyridinemethanol (1.635 g, 0.015 mol)in 10 mL of CH2Cl2, at 0 C under N2, was added dropwise trifluoromethanesulfonic acid (1.327 mL, 0.015 mol). Ayellow-brown oil rapidly separated out.

An additional equivalent of 4-piridinemethanol (1.635 g, 0.015 mol) was added to this mixture and the solventwas removed under reduced pressure to give an oil.To this oil was added ethylene sulfide (0.891 mL, 0.015 mol) and the resulting homogeneous mixture was heated (oil bath) at about 60 C for 3 h.

The reaction mixture was then taken up in 15 mL of H20 and the aqueous solution was washed with CH2Cl2 (5 x 5 mL). After removing residual organic solvent in vacuo the aqueous solution was applied to a C18 reverse-phase column. Elution with H2O and subsequent evaporation of the relevantfractions afforded an oil which was further dried in vacuo over P205to give the product (4.64 g, 97%) as a colourless oil. ir (film) vrnax: 3455 (s, OH), 2565, (w, SH) cm-1; 1Hnmr (d6-acetone) # : 9.07, 8.18 (ABq, J=6.8 Hz, 4H, aromatic), 5.03 (s, 2H, CH2OH), 4.96 (t, J=6.5 Hz, 2H, N-CH2), 4.09 (brs, 1H, -OH), 3.5-3.1 (m, 2H, S-CH2), 2.25 (brs, 1H, -SH).

B. p-Nitrobenzyl(5R, 6S)-3-[2-(4-hydroxymethylpyridinio)ethyl thio] - 6 - [1- (R) - hydroxyethyl] - 7 oxo - 1 - azabicyclo[3.2.0]hept. - 2 - ene - 2 - carboxylate diphenylphosphate

To a solution of p-nitrobenzyl (5R, 6S) - 6 - [1 - (R) - hydroxyethyl] -3,7 - dioxo -1 - azabicyclo[3.2.0]heptane - 2 - carboxylate (0.348 g, 1.0 mmol) in 6 mL of dry acetonitrile, at 0 C under N2, was added dropwise diisopropylethylamine (0.191 mL, 1.1 mmol) followed bydiphenyl chlorophosphate (0.228 mL, 1.1 mmol). The resulting golden-yellow solution was stirred at 0 C for 40 min.To this solution was added a solution of 4- hydroxymethyl - 1 - (2 mercaptoethyl)pyridinium trifluoromethanesulfonate (0.447 9,1.4 mmol) in mL of acetonitrile, followed by diisopropylethylamine (0.191 mL, 1.1 mmol). A reddish-black gum separated from the reaction mix ture. After 20 min at 0 C the reaction mixture was filtered and concentrated in vacuo. The residue was taken up in a minimum volume of acetonitrile-H2O (1:1) and applied to a C18 reverse-phase column.

Elution with 25% acetonitrile-H2O and subsequent lyophilization ofthe relevant fractions gave the product (0.353 g, 47%) as a cream-coloured solid. ir (KBr) vmax: 3240 (br, OH), 1775 (ss-lactam CO), 1695 (-CO2PNB)cm-1 ; Hnmr (d6-acetone) # : 9.24-7.84 (m, BR, aromatic), 7.4-6.9 (m, 1 OH, diphenylphosphate), 5.52, 5.24 (ABq, J=14Hz, 2H, benzylic), 5.15-4.80 (m, 4H), 4.45-3.05 (m, 7H), 1.35 (d, J=6.6 Hz, 3H, CHMe).

C. (5R,6S) - 3 - [2 - (4 - hydroxymethylpyridinio)ethyl thio]-6-[1-(R)-hydroxyethyl]-7-oxo-1azabicyclo[3.2.0]hept-2-ene-2-carboylate

A mixture of p-nitrobenzyl (5R,6S) - 3 - [2 - (4 hydroxymethylpyridinio)ethylthio]-6-[1-(R)hydroxyethyl)-7-oxo-1-azabicyclo[3.2.0]hept-2ene - 2 - carboxylate diphenylphosphate (0348 g, 0.465 mmol) and 10% palladium - on - charcoal (0.35 g) in 11 mLof phosphate buffer (0.05 M, pH 7.4), 5 mL of THF and 10 mL of ether was hydrogenated at 40 psi for 1.25 h.The mixture was then filtered through a Celite pad and the aqueous phase was washed with ether (3x). The pH ofthe aqueous solution was then adjusted to 7.0 using additional pH 7.4 buffer. After removing residual volatiles in vacuo the aqueous solution was applied to a C18 reverse-phase column.

Elution with 2% acetonitrile-H2O and subsequent lyophilozation gave a yellow-brown solid. This material was rechromatographed (C18 reverse-phase/H2O) to give the desired product (0.060 g, 36%) as a light yellow solid. ir (KBr) vmax : 3400 (br, OH), 1755 (ss-lactam CO), 1590 (-CO2-)cm-1 ; Hnmr (D2O) # : 8.73,7.96 (ABq, J=6.8 Hz, 4H, aromatic),4.93 2H, CH2OH), 4.77 (t, J=6.0 Hz, 2H, N-CH2), 4.15 (d of q, j=J'=6.3 Hz, 1 H, H-1 '), 3.96 (d oft, J=9.2 Hz, J'=2.6 Hz, 1H, H-5), 3.65-3.20 (m, 3H), 3.13-2.62 (m, 2H), 1.21 (d, J=6.3 Hz, 3H, CHMe) ; uv (H2) #max : 295 (#6880), 256 (#5595), 244 (#8111) nm ; t1/2 (pH 7.4, 36.8 CV) 14.5 h Example 5 Preparation of 3- [2 - (1- (2 - methylpyridinium)) ethylthio]-6&alpha;-[1-(R)-hydroxyethyl]-7-oxo-1- azabicyclo(3.2.0)hept-2-ene-carboxylate

A. 1-(2-mercaptoethyl)-2-methylpyridinium methanesulfonate

To a suspension of 2-methylpyridinium methanesulfonate in 2-methylpyridine prepared by the addition of methanesulfonic acid (0.65 mL, 0.010 mol) to cold 2 - methylpyridine (2.17 mL, 0.022 mol) was added ethylene sulfide (0.655 mL, 0.011 mol).

The reaction mixture was stirred under a nitrogen atmosphere at 55 C for 21 h, cooled to 23 C and diluted with watr (5 mL). the aqueous solution was washed with ether (6 x4 mL) pumped to remove traces of organic solvents and poured on top of a column (2.5 x 10.0 cm) of p-bondapakC-1 8.The column was eluted with water and lyophilization of the appropriate fractions gave 2.13 g (85%) of the title compound, ir (film) vmax: 2520 (SH), 1623 (pyridi nium)1574, 1512, 1485, 1412, 1195(sulfonate), 1038 cm-1, Hmr (DMSO-d6+D2O) o: 2.37 (3H, s, CH3SO3-), 2.83 (3H, s, CH3 on pyridinium), 3.09 (2H, J=6.9 Hz, CH2S), 4.71 (2H, t, J=6.9 Hz, CH2N+0, 7.93 (2H, m, Hm of pyridinium), 8.44 (1 H, H, m, Hp of pyridinium), 8.89 (1H, m, Ho of pyridinium), uv (H2O) #max : 266 (#3550) m .

B. Paranitrobenzyl 3-[2- (1- (2-methylpyridinium) ethylthio]-6&alpha;-[1-(R)-hydroxyethyl-7-oxo1- azabicyclo(3.2.0)hept-2-ene-2-carboxylate diphenylphosphate

To a cold (0 C) solution of p-nitrobenzyl 6&alpha;-[-(R)- hydroxyethyl] - 3,7 - dioxo -1 - azabicyclo(3.2.0)heptane - 2 - carboxylate (0523 9, 1.50 mmol) in acetonitrile (6 mL) kept under a nitrogen atmosphere was added diisopropylethylamine (0.314 mL, 1.80 mmol)followed by diphenyl chlorophosphate (0.373 mL, 1.80 mmol).The reaction mixture was stirred for 30 min at 0 C and treated with solution of 1 - (2 - mercaptoethyl) - 2 - methylpyridinium methanesulfonate (0.530 g, 2.16 mmol) in acetonitrile (18 mL.) followed by diisopropylethylamine (0.314 mL, 1.8 mmol). The reaction mixture was stirred at 0 C for 1 h diluted with cold (00C) water (26 mL) and poured on top of a column (3.5x7.0 cm) of p-bondapak C-18. Elution ofthe column with 25% acetonitrile - 75% water and with 50% acetonitrile50% water gave after lyophilization of the appropriate fractions 1.06 g, (96% ) of the title compound as a yellowish powder, ir (KBr) vmax: 3650-3100 (OH), 1770 (C=O of ss-lactam), 1696 and 1690 (C=O of PNB ester), 1630 (pyridinium), 1595 (phenyl), 1518 (NO2), 1335 (NO2), 890 cm-1 (NO2), 1Hmr(DMSO, d6) 5::1.15 (3H, d, J=6.1 Hz, CH3CHOH), 2.87 (s, CH3 on pyridinium), 3.6-4.4 (2H, m, H-5, CH3CHOH), 4.75 (2H, m, CH2N+), 5.37 (center of ABq, J=14 Hz, CH2 of PNB), 6.5-7.4(10 H, m, phenyl), 7.70 (2H, d, J=8.8 Hz, Ho of PNB), 8.0 (2H, m, Hm of pyridinium), 8.24 (2H, d, J=8.8 Hz, Hm of PNB), 8.50(1 H, m, Hp of pyridinium), 8.95 (1 H, 1, brd, J=6.1 Hz, Ho of pyridinium), uv (H2O) Ajax:: 265 (#11990), 314 (#8020) m C. 3-[2-(1-(2-methylpyridinium))ethylthio]-6&alpha;- [1-(R)-hydroxyethyl]-7-oxo-1azabicyclo(3.20)hept- 2 - ene - carboxylate

To a solution of p-nitrobenzyl 3 - [2 - (1 - (2 methylpyridinium)) ethylthio) - 6&alpha; - [1 - (R) - hydroxyethyl] - 7 - oxo - 1 - azabicyclo (3.2.0) hept-2-ene-2- carboxylate diphenylphosphate (0.66 g, 0.90 mmol) in wettetrahydrofuran (34 mL) was added ether (34 mL), potassium phosphate monobasic-sodium hydroxide buffer (0.15 M, 16.5 mL, pH 7.22) and 10% palladium on charcoal (0.66 9). The resulting mixture was hydrog enated under 40 psi at 23 C for 1.25 h.The organic layer was separated and extracted with buffer (2 x 6 mL). Water layers were combined, filtered through a Celite pad, washed with ether (40 mL), pumped to eliminate traces of organic solvents and poured on top of a column (2.5 x 10 cm) of u-bondapak C-18. Elution ofthe column with water and lyophylization ofthe appropriate fractions gave the title compound 0.098 g (31 %) as a yellowish powder, ir (KBr)) v max 3650-3100 (OH) ; 1755 (C=O of ss-lactam), 1630 (pyridinium), 1595 cm-1 (carboxylate), Hmr (D2O) o: 1.20 (3H, d, J=6.3 Hz, CH3CHOH), 2.83 (s, CH3 on pyridinium), 2.7-3.1 (5H, H-4, CH3 on pyridinium), 3.1-3.7 (3H, m, CH2S, H-6),3.90 (dd, J=9.1 Hz.J=2.6 Hz, H-5), 3.1 (m, CH3CHOH), 4.78 (t, J=6.2 Hz, CH2N+),7.8 (2H, m, Hm of pyridinium), 8.3 (1 H, m, Hp ofpyridinium), 8.65 (1H, m, Ho of pyridinium), uv (H2O) #max : 268 (#9350), 296 (#8840) mp, [&alpha;]D +410 (c0.5, R2O), T112 = 15.0 h (measured at a concentration of 10-4 M in phosphate buffer pH 7.4 at36.8 C).

Example 6 Preparation of 3- [2 - (1- (4 - methylpyridinium) ethylthio]-6&alpha;-(R)-hydroxyethyl]-7-oxo-1- azabicyclo (3,2.0) hept-2- ene -2-carboxylate

A. 1- (2- mercaptoethyl) - 4 - methylpyridinium methanesulfonate

To a suspension of 4-picolinium methanesulfonate in 4-picoline prepared by the addition of methanesulfonic acid (0.65 mL, 0.10 mol) to 4-picoline (2.14 mL, 0.022 mol) in cooling was added ethylene sulfide (0.655 mL, 0.011 mol). The reaction mixture was stirred under a nitrogen atmosphere at 55 C for 24 h, cooled to 23 C and diluted with water (5 mL) and ether (10 mL).The organic layerwas separated and the aqueous layer was washed with ether (5 x 5 mL) and applied on top of a column (2.5 x 20 cm) of -bondapak C1-18 after traces of ether have been removed under reduced pressure. Elution ofthe column with 15% acetonitrile 85% water mixture gave after lyophylization ofthe appropriate fraction a colorless syrup 2.066 g (100%), ir (film) vmax: 2500 (SH), 1640 (pyridinium), 1572, 1520, 1478, 1200 (sulfonate), 1040,833 and 768 cm-1, 'Hmr (DMSO-d6ì # : 2.31 (3H, s, CH3SO3-), 2.62 (s, CH3 on yridinium), 2.2-2.9 (4H, SH, CH3 on pyridinium), 3.04 (2H, m, CH2s), 4.68 (2H, t, J=6.4 Hz, CH2N+), 8.01 (2H, d, J=6.6 Hz, Hm of pyridinium), 8.89 (2H, d, J=6.6 Hz, Ho of pyridinium), uv (R2O) Ajax: 256 (e41 00)221 (#7544) mil.

B. 1-(2-mercaptoehtyl) -4-methylpyridiniump toluenesulfonate

To a suspension of p-toluenesulfonic acid (1.72 9, 0.01 mol) in benzene (6.5 mL) was added 4-picoline (1.17 mL,0.012 mL). The resulting mixture was stirred under a nitrogen atmosphere at 23 C for 30 min, treated with ethylenesulfide (0.65 mL, 0.011 mol) and stirred at 75 for 24 h. More ethylenesulfide (0.65 mL, 0.011 mol) was added and the stirring was continued at 75 C for 24 h more. The reaction mixture was cooled to 23 C and diluted with water (5 mL) and ether (8 mL). The aqueous layer was separated and washed with ether (3 x 8 mL).The traces of organic solvents were removed under vacuum and the compound was chromatographed on -bondapak C-1 8 with water as eluting solvent to give 2.94 g (90%) of the title compound as a colorless syrup; ir (film vmax: 2510 (SH) 1640 (pyridinium), 1595, 1582, 1475, 1200 (sulfonate), 1031, 1010, 818 cm-1, Hmr (DMSO, d6) # : 2.29 (3H, s, CH3 on pyridinium), 2.61 (s, CH3 Ph), 2.4-2.8 (4H, SH, CH3 Ph), 3.03 (2H, m[addition of D2O gave att, J= 6.4 Hz, at 3.04], CH2S), 4.68 (2H, t, J=6.4 Hz, CH2N+), 7.11 7.49 (4H, 2d, J=7.9 Hz, Phenyl), 8.00 (2H, d, J=6.5 Hz, Hm of pyridinium), 8.89 (2H, d, J6.5 Hz, Ho of pyridinium), uv (H2O) #max :: 256 (#4315), 222 (E17045) mp.

C. Paranitrobenzyl3 - [2 - (1- (4 - methylpyridinium)) ethylthio[-6&alpha;-[1-(R)-hydroxyethyl]-7-oxo-1- azabicyclo (3.2.0) hept - 2 - ene - 2 - carboxylate diphenylphosphate

To a cold (0'C) solution of p-nitrobenzyl 6&alpha; - [1 [1-(R)- hydroxyethyl] -3,7 - dioxo - 1 - azabicyclo (3.2.0) heptane - 2 - carboxylate (0.522,1.5 mmol) in acetonitrile (6 mL) kept under a nitrogen atmosphere was added diisopropylethylamine (0.314 mL, 1.8 mmol) followed bydiphenyl chlorophosphate (0.373 mL, 1.9 mmol).The reaction mixture was stirred for 45 min and treated dropwise with a solution of 1 - (2 mercaptoethyl)-4-methylpyrididium methanesul fonate (0.539,2.15 mmol) in acetonitrile (1.8 mL) followed by dissopropylethylamine (0.314 mL, 1.8 mmol).The reaction mixture was stirred at at 0 C for 1 h, diluted with cold (0'C) water (24 mL) and poured on top of a column (2.5 x 8.5 cm) of u-bondapax C-i 8.

Elution of the column first with 25% acetonitrile -75% water mixture (100 mL) then with 50% acetonitrile 50% water mixture (100 mL) afforded after lyophylization of the appropriate fractions 0.91 9 (83%) of the title compound as a yellowish powder, ir (KBr) v max: 3700-2800 (OH), 1770 (C=O of ss-lactam), 1700 (C=O of PNB ester), 1640 (pyridinium), 1595 (phenyl), 1520 (NO2), 1340 (NO2), 890 cm-1 (NO2), Hmr (DMSO, d6) # : 1.16 (3H, d, J=6.2 Hz, CH3CHOH), 2.61 (s, CH3 on pyridinium), 3.1-3.7 (3H, m, H-6, CH2S), 3.7-4.4 (2H,m,H-5, CH3CHOH), 4.79 (2H, brt, J=6.3 Hz, CH2N+), 5.17 (d, J=4.9 Hz, OH), 5.37 (center of ABq, J=14.1 Hz, CH2 fo PNB), 6.7-7.4(10 H, m, phenyl), 7.69 (2H, d, J=8.8 Hz, Ho of PNB), 8.00 (2H, d, J=6.5 Hz, Hm of pyridinium), 8.23 (2H, d, J=8.8Hz, Hm of PNB), 8.92 (2H, d, J=6.5 Hz, Ho of pyridinium), uv (H2O) Ajax: 262 (#10835), 311 (#9670) mp.Anal. calcd. for C36H36N3O10SP 1.5 H2O: C 56.84, H 5.17, N 5.52, S 4.21 ; found C56.89, H5.13, N. 5.19, S 4.41.

D. 3-[2-(1-(4-methylpyridinium)ethylthio]-6&alpha;- [1 - (A) - hydroxyethyl) - 7- oxo - 1 - azabicylo (3.2.0) hept- 2- ene - 2- carboxylate

To a solution of p-nitrobenzyl 3 - [2 - (1 - (4 methylpyridinium)-ethylthio]-6&alpha;-[1-(R- hydroxyethyl)-7- oxo - 1 - azabicyclo (3.2.0) hept - 2 ene 2 - carboxylate diphenylphosphate (0.587 9, 0.80 mmol) in wettetrahydrofuran (30 mL) was added ether (30 mL), potassium phosphate mono basicsodium hydroxide buffer (0.15 M, 14.7 mL, pH 7.22) and 10% palladium on charcoal (0.59 g). The resulting mixture was hydrogenated under 40 psi at 23 C for 1.25 h.The organic layer was separated and extracted with the buffer (2 x 6 mL). The aqueous extracts were combined, filtered through a Celite pad, washed with ether (3 x 20 mL), pumped to remove traces of organic solvents and poured on top of a column (2.5 x 10cm) of -bondapak C-1 8.Elution ofthe column with water and lyophylization ofthe appropriate fractions gave 0.136 9 (49% ) ofthe title compound as a yellowish powder, ir (KBr) vmax: 3700-3000 (OH), 1770 (C=O of ss-lactam), 1642 (pyridinium) 1592 cm-' (carboxylate), qHmr (D2O) # : 1.19 (3H,t, J=6.3 Hz, CH3CHOH), 2.59 (3H, s, CH3 on pyridinium), 2.84 (d, J=9.1 Hz, H-4), 2.90 (d, J=9.1 Hz, H-4), 3.0-3.6 (3H, m, SH2S, H-6), 3.86 (dd, J=9.1 Hz, J=2.6 Hz, H-5), 4.12 (m, CH3CHOH)), 4.5-4.9 (CH2N+ masked by HOD), 7.80 (2H, d,J=6.6 Hz, Hm of pyridinium),8.58 (2H, d, J=6.6 Hz, Ho of pyridinium) uv (H2O) Ajax: 256 (E5510), 262 (E5360), 296 (E7050) m, [0:]D23 + 20.8 (C 0.48, H20), T1/2 = 12.8 h (measured at a concentration of 10-4 M in a phosphate buffer pH 7.4 at 36.8 C).

Example 7 Preparation of(5R) 3 - [2 - (4 - methylthiopyridinio) ethylthio]-(6S)-[(1R)-hydroxyethyl]-7-oxo-1azabicylo [3.2.0] hept - 2 - ene - 2 - carboxylate

a. 4-Methylthiopyridine

4-Mercaptopyridine (5.55 g, 50.0 mmol; Aldrich) was dissolved in boiling abs. EtOH(50 mL). The insoluble material was removed by filtration over Celite. The filtrate was heated to re-dissolved, and when it cooled to ca. 50 C, methyl iodide (3.17 mL, 51.0 mmol; Aldrich) was added at once. The mixture was cooled to crystallize.Filtration of the solid gave 6.77 g (26.7 mmol, y.53.5% ) ofthe title compound as hydriodide: 'Hmr(D20)6: 2.70 (3H, s,--SCH3) and 7.65-7.77-8.35-8.48 ppm (4H, A2B2 type, aromatic Hs) ; ir (Nujol) #max : 1615,1585 (aromatic and 780 cm-1; uv (H2O) #max : 227 (E2.02 x 104) and 298 nm (81.64 x 104).

The hydriodide (6.33 g, 25.0 mmol) was dissolved in H2O (40 mL) and the insoluble material was removed and washed with H2O (10ml). To the filtrate was added at 0-5 NaOH pellet (5 g) and extracted with Et2O (3 e 25 mL), saturating the aqueous layer with NaCI. The combined organic extracts were washed with brine (x 2) dried (MgSO4) and evaporated, yielding 2.92 g (23.4 mmol, overall yield 50%) ofthe title compound as an oil : Hmr (CDCl3) # : 2.48 (3H, s, -SCH3) and 7.03-7.13-8.38-8.48 ppm (4H, A2B2 type, aromtic-Hs) ; ir (film) #max : 1580a nd 80 cm-1.

*Preparation ofthis compound was reported by King and Ware, J. Chem. Soc., 873 (1939). The procedure, described in this this reference was followed.

B. 4-Methylthio-N-(2-mercaptoethyl) pyridinium methanesulfonate

4-Methylthiopyridine (2.75 9, 22.0 mmol) was added slowly to methanesulfonic acid* (0.65 mL, 10.5 mmol) by cooling in an ice-bath. To this solid was added ethylene sulfide* (0.66 mL, 11.0 mmol, Aldrich) and the mixture was heated at 50-60 C for 21 h. As reaction proceeds the solid wentto solution. After cooling, the reaction mixturewas dissolved in H2O (5 mL) and washed with Et2O (5 x 4 mL). The cloudy aqueous layer was filtered over Celite and the filtrate was purified by reverse phase silica gel column chromatography (C18 micro bondapak 10g) eluting with H2O. Each fraction of 10 mLwas collected Fractions 2 and 3were combined and repurified by the reverse phase column. Fraction 2 gave 1.258 g (4.48 mmol, y. 42.6%) of the title compound as a viscous oil : Hmr (DMSO-d6, CFT-20) 5: 2.32 (3H, s, MeSO3#), 2.72 (3H, s, - SMe), 2.68 (1H, m, SH), 2.9-3.2 (3H, m, -CH2S), 4.59 (2H, t, J=6.4 Hz, -CH2N#), 7.97 (2H, "d", J=7.2 Hz, aromatic-Hs) and 8.72 ppm (2H, "d", J=7.2 Hz, aromati-Hs) ; ir (neat) vmax: 1630, 1200- (br, - SO3#), 7.83 and 770 cm-1.

*These reagents were distilled prior to use.

C. (SR) p-nitrobenzyl 3 - [2 - (4 - Methylthiopyridino) ethylthio] - (6S)-[(1R)- hydroxyethyl] -7 - oxo - 1 - azabicyclo [3.2.0] hept-2-ene-2- carboxylate chloride

To a solution of (5R) p-nitrobenzyl 3,7 -dioxo - (6S) [(1R)-hydroxyethyl] - 1 -azabicyclo (3.2.0] heptane (2R) - carboxylate (475 mg, 1.36 mmol) and diisopropylethylamine (0.24 mL, 1.4 mmol) in CH3CN (5 mL) was added at 0 -5 C under a nitrogen atmosphere diphenyl chlorophosphate (0.29 mL, 1.41 mmol). The mixture was stirred at 0 -5 , for 30 min. To this mixturewas added an oilysuspension of 4 methylthio - N - (2 - mercaptoethyl) pyridinium methanesulfonate (678 mg, 1.45 mmol; 60% pure) in CH3CN (1.5 mL) followed bydiisopropylethylamine (0.24 mL), 1.4 mmol).The mixture was stirred at 0 -5 C for 1 h. Immediately after addition of the base, yellowish precipitate formed. The precipitate was filtered and washed with cold CH3CN (3 mL), yielding 413 mg of yellowish solid. This was triturated from 10% MeOH in H2O (5 mL) to obtain 341 mg (0.618 mmo, y-45.4%) of the title compound as white crystals : mp 118 -120 C ; Hmr (DMSO-d6, CFT-20) # : 1.16 (3H, d, J=6.1 Hz, 1'-CH3), 2.72 (3H, s, -SCH3), 3.1-3.7 (5H, m), 3.7-4.3 (2H, m), 4.71 (2H, t, J=6.3 Hz, -CH2N#), 5.15 (1H, d, J=4.9Hz, OH), 5.20-5.35-5.405.55 92H, ABq, CO2CH2-Ar), 7.70 (2H, "d" J=8.8Hz, nitrophenyl-Hs), 7.97 (2H, "d", J=7.0Hz, pyridinio Hs), 8.25 (2H, "d", J=8.8 Hz, nitrophenyl-Hs), and 8.76 ppm (2H, "d", J=7.1 Hz, pyridinio-Hs); Ir (Nujol) #max : 3250 (OR), 1775 (ss-lactam), 170 (ester) and 1625 cm-1 (pyridinio); uv (abs, EtOH) Ama, 308 nm (#4.47 104) ; [C]D + 24.8 (c0.5, MeOH) ; Anal. calcd. for C24H26N3O6S2Cl.H2O : C 50.56, H 4.95, N 7.37; found: C 50.63, H 4.72, N 6.89.

D. (5R)3-[2- (4- Methylthioyridinio) ethylthio) (6S)-[(1R)-hydroxyethyl-7oxo-1-azabicyclo [3.2.0]hept-2-ene-2-carboxylate

(5R)p-Nitrobenzyl-3-[2-(4-methylthiopyridino) ethylthio] (6S)-[(1R)-hydroxyethyl]-7-oxo-1azabicyclo[3.2.0]hept-2-ene-2-carboxylate chloride (380 mg, 0.688 mmol) was dissolved in THF (31.5 mL) and pH 7.40 phosphate buffer (31.5 mL; 0.05M Fisher) and diluted with Et2O (31.5 mL). This solution was mixed with 10% Pd-C (380 mg, Engelhard) and hydrogenated at35 psi on the Parr shaker at room temperaturefor 1 h. The aqueous layer was filtered over Celite to remove the catalyst and the Celite pad was washed with H2O (2 x 5 mL).

The filtrate and washing were combined and washed with Et2O (2 x 30 mL). The aqueous layer was pumped off to remove any organic solvents and purified by reverse phase column chromatography (C18 microbondapak, 13 g, Waters Associates) eluting with H2O. Fractions having a uvabsorption at307 nm were collected (ca. 1 L) and lyophilized to obtain 127 mg (0.334 mmol, y. 48.5%) of the title compound as a yellowish powder: 1Hmr (D2O, CF5-20) # :: 1.20 (3H, d, J=6.4 Hz, 1'-CH3), 2.64 (3h, s, - SCH3), 2.81 (2H, m, -SCH2-), 3.19 (1H, dd, J6-1'=6.1 Hz, J6-5=2.6Hz, 6-H), 3.32 (2H, dd, J=11 Hz, J=5.5 Hz, 4-Rs), 3.92(1 H, H, dt, J=9.2 Hz, J5-6=2.6Hz, 5-H), 4.1 (1H, m, 1'-H), 4.61 (2H, t, J=5.9 Hz, - CH2N#), 7.70 (2H, "d", J=7.1 Hz, aromatic-Hs), and 8.40 ppm (2H, "d", J=7.1 Hz, aromatic-Hs) ; ir (KBr, disc) #max : 3400 (OH), 1750 (sslactam), 1630 (pyridinium) and 1590 cm-1 (carboxylate); uv (H2O) Ajax: 231 (E9800) and 307 nm (E2500); [&alpha;]D +3.14 (c0.5, H2O).

Example 8 Preparation of3- [2 - (3 - methoxy- 1 -pyridi nium) ethylthio]-6&alpha;-[1'-(R)-hydroxyethyl]-7-oxo- 1-azabicyclo(3.2.0)-hept-2-ene-2-carboxylate

A. 1-(2-mercaptoethyl)-3-ethoxypyridinium methanesulfonate

To percooled (5 C) 3-methoxypyridine (698 mg, 6.4 mmol) was added dropwise methanesulfonic acid (0.216 mL, 3.05 mmol) andethylene sulfide (0.19 mL, 3.2 mmol). The mixture ws then heated at 60 C for 18 h, cooledto 20 C, diluted with water (1OmL) and washed with ether (3 x 10 mL). The aqueous phase was pumped under high vacuum for 15 min and poured on a C18 reverse phase column. The title compound was eluted with water.The appropriate fractions were combined and evaporated under high vacuum to give the desired thiol (61.6 mg, yield 76.3%); ir (CH2Cl2) vmax: 2550 (w, SR) and 1620,1600, 1585 cm-1 (m, aromatic) ; Hmr (DMSO d6) # :: 8.90-7.90 (4H, m, aromatic C-H),4.72 (2H, t, J=6.6 Hz, CH2N+),4.01 (3H,s, OCH3) 3.5-3.0 (m,hidden CH2S), 2.66 (1H, dd, J=9.5Hz, J=7.5Hz, SH) and 2.31 ppm (3H, s, CH3SO3-) B. para - Nitrobenzyl 3[2 - (3- methoxy -1- pyridinium chloride) ethylthio]-6&alpha;-[1'-(R)-hydroxyethyl]-7- oxo-1-azabicyclo(3.2.0)-hept-2-ene-2 carboxylate

A cold (0 C) solution of p - nitrobenzyl 6Os - [1 ' - (R) hydroxyetheyl] -3,7 - dioxo - 1 - azabicyclo - (3.2.0) heptane-2-carboxylate (1.04g, 3 mmol) in acetonitrile (12 m L) was treated d ropwise with diisopropylethylamine (0.63 mL, 3.6 mmol) and diphenylchoiorophosphate (0.75 mL, 3.6 mmol) and stirred at 0 C for 30 min.The resulting enol phosphate wastreated with 1-(2-mercaptoethyl)-3-methoxy pyridinium methanesulfonate(l. 14 g, 4.30 mmol) in CH3CN(7 mL), diisopropylethylamine (0.63 mL, 4.30 mmol), stirred for 30 min. and cocled at -10 C for 30 min. The solid that precipitated out ofthe mixture was filtered, washed with cold acetonitrile (2 mL) and dried to givethe title compound (1.32 g, yield 82%); ir (nujol) #max 3320 (m, OR), 1780,1765 (s, (3- lactam C=O), 1700,1695 (m, esterC=O) and 1520cm-1 (s, NO2); 1Hmr (DMSO d6) 5:9.01(1 H, bs, H-3 aromatic), 8.75 (1 H, bd, J=5.4 Hz, H-6 aromatic), 8.35-7.95 (4H, m, H-aromatic), 7.70 (2H, d, J =7.7 Hz, H-aromatic), 5.37 (2H, center of ABq, J= 13 Hz, CH2PNB), 5.17 (1 H, d, J=4.9 Hz, OH), 4.87 (2H, t, J=6.3 Hz, CH2-N#), 4.35-3.75 (2H, m, H-5 and H-i'), 4.00 (3H, s, OCH3) 3.56 (part of at, J= 6.3 Hz, CH2S), 3.5-3.20 (3H, m, H-6, H-3) and 1.16 ppm (3H, d, J=6.1 Hz, CH3CHO).

C. 3-[2-(3-methoxy-1-pyridinium)ethylthio]-6&alpha;- [1' - (R)-hydroxyethyl] - 7- oxo - 1- azabicyclo(3.2.0) hept-2-ene-2-carboxylate

A solution of para - nitrobenzyl 3 [2 - (3 - methoxy - 1 - pyridinium chloride)ethylthio] - 60: - [1'-(R)- hydroxyethyl] -7 - oxo - 1 - azabicyclo (3.2.0) - hept - 2 ene-2-carboxylate (600 mg, 1.12 mmol) in THF (25 mL), ether (25 mL) and pH 7.4 phosphate buffer (0.1 M, 25mL)was hydrogenated in a Parr shaker over 10% Pd/C (1.1 g)for 1 h at40 psi. The mixture was diluted with ether and the aqueous phase was filtered through a &num;52 hardened filter paper.The aqueous layerwaswashedwith ether (2 x 20 mL) pumped undervacuum and poured on a silica gel reverse phase column. The title compound was eluted with water containing 2 and 5% acetonitrile. The appropri ate fractions were combined and lyophilized to give a yellow solid that was repurified by hplc to give the penem carboxylate (150 mg, 38%) ; ir (nujol) #mex 1750 (s, ss - lactam C=0) and 1580 cm-' (s, carboxylate); 1Hmr (D20) # : (8.55-8.30 (2H, m, H-2, H-6 aromatic); 8.17-7.75 (2H, m, H-3, H-4 aromatic), 4.77 (2H,t,J=5.9 Hz, CH2N#). 4.10 (1 H, part of 5 lines, J=6.3 Hz, H-1 '),3.97 (3H, s, OCH3), 3.85, 3.82 92 lines, part of dt, J=2.6 Hz, part of H-5), 3.42 (2H, t, J=5.9 Hz, CH2-S), 3.25(1 H, dd, J=6.1 Hz, J=2.6 Hz, H-6), 2.99-2.60 (2H, 6 lines, part of H-4) and 1.20 ppm (3H, d, J=6.4 Hz, CH3) ; uv (H2O, c0.05]#max : 290 (#10517), 223 (#6643) ; T1/2 0.1 M pH 7.4 phosphate buffer, 37 C) 20h.

Example 9 Preparation of (5R; 6S) - 3 - [2 - (3 - methylthiopyridinio) ethylthio]-6-[1-(R)-hydroxyethyl]-7-oxo-1azabicyclo[3.2. O]hept - 2 - ene - 2 - carboxylate

A. 3 - Methylthio - 1- (2 - mercaptoethyl)pyridinium chloride

To a solution of 3 - methylthiopyridine1 (2.00 g, 0.016 mol0 in 10 mLofether was added 15 mLof 1 N HCI and the mixture was well shaken. The aqueous phase was separated, washed with 10 mL of ether and then evaporated. The residual hydrochloride was then dried in vacuo (P2O5) to give a white solid.To this solid hydrochioride was added 3- methylthiopyridine (1.88 g, 0.015 mol) and ethylene sulfide (0.89 mL, 0.015 mol) and the resulting mixture was heated (oil bath) at 55-65 C under N2 for 15 h. This gave a slightly turbid oil which was taken up in 125 mL of H2O and washed with CH2Cl2. The aqueous solution was concentrated to about 25mL and then a few drops of acetonitrile were added to make the mixture homogeneous. The resulting aqueous solution was applied to a C18 reverse-phase column. Elution with H2O and subsequent evaporation of the relevant fractions afforded the product (2.66 g 80%) as a pale yellow,viscous oil. ir(film) vmax: 2410 (br, -SH) cm-1 ; Hnmr (d6-DMSO+D2O) # 8.88-7.88 (m, 4H, aroma- tic), 4.70 (t, J=6.5 Hz, 2H, N-CH2), 3.08 (skewedt, J=6.5 Hz, 2H, S-CH2), 2.64 (s, 3H, S-Me). 1Prepared by the method of J. A. Zoltewiez and C. Nisi, J. Org.

Chem. 34,765 (1969).

B. p - Nitrobenzyl (5R, 6S)-3-[2-(3- methylthiopyridinio)ethyl thio]-6-[1- (A) - hydroxyethyll -7 - oxo - 1 - azabicyclo[3.2.0]hept - 2- ene - 2 - carboxylate chloride

A solution of p - nitrobenzyl (5R, 6S) - 6 - [1 - (R) - hydroxyethylj - 3,7 - dioxo -1 - azabicyclo[3.2.0]heptane-2-carboxylate (0.522 g, 1.50 mmol) in 7 mLofdry acetonitrile was cooled at 0 C and then diisopropylethylamine (0.287 mL, 1.65 mmol) was added dropwise. To the resulting yellowbrown solution was added dropwise diphenyl chlorophosphate (0.342 mL, 1.65 mmol) and the reaction mixture was kept at 0 C for 30 min.Diisopropylethylamine (0.313 mL, 1.80 mmol) was then added, followed by a solution of 3 - methylthio - 1 - (2 mercaptoethyl)pyridinium chloride (0.398 g, 1.80 mmol) in 0.70 mL of dry DMF. About a minute after the addition was complete a precipitate separated from the reaction mixture and further cooling at -10'Cfor 10 min gave a solid orange-coloured mass.

This solid was subsequently triturated with acetonitrile and the residue was collected by filtration. The residue was washed with acetonitrile, then acetone and finally dried in vacuoto givethe product (0.455 g, 55%) as a cream-coloured solid. The combined filtrate was evaporated to give a yellow oil which was taken up in a minimum volume of acetonitrile and cooled at 0 C for 30 min. Filtration of this mixture afforded an additional 0.139 g of the product as a light yellow solid. The combined yield was 0.594 g (72%).

ir (KBr) vmax: 3345 (br, -OH), 1770 (ss - lactam CO), 1680 (-CO2PNB)cm-1 ; Hnmr (d6-DMSO) # : 8.98-7.96 (m, 4H, pyridinium aromatic), 8.20-7.65 (ABq, J=7.0 Hz, 4H, PNB aromatic), 5.53-4.80 (m, 4H0, 4.3-3.7 (m, 2H), 3.6-3.25 (m, 6H), 2.66 (s, 3H, S-Me), 1.16 (d, J=6.0 Hz, 3H, CHMe).

C. (5R, 6S)-3-[2-(3-methylthiopyridinio)ethylthio] -6-[I-(RJ- hydroxyethyl]-7-oxo -?- azabicyclo[3.2.0]hept-2-ene-2-carboxylate

To a mixture of p-nitrobenzyl (R,6S) - 3 - [2 - (3 methylthiopyridinio)ethylthio]-6-[1-(R)-hydroxy ethyl]-7-oxo-1-azabicyclo[3.2.0]-hept-2-ene-2 carboxylate chloride (0.551 g, 1.0 mmol) and 10% palladium-on-charcoal (0.55 g) in 25 mL of phosphate buffer (0.05 M, pH 7.4) was added mL of TRF and 25 mL of ether. This mixture was hydrogen ated (Parr) at 40 psi for 1 h. The reaction mixture was then filtered through Celite and the filter cake was washed with H2O and ether. The aqueous phase was separated and washed with additional ether (3 x).

After removing residual organic solvents in vacuo the aqueous solution was cooled at 0 C and the pH was adjusted to 7.0 with saturated aqueous NaCHO3.

This solution was immediately applied to a C18 reverse-phase column. Elution with H2O and subse quentlyophilization of the relevant fractions afforded 0.25 g of a bright yellow solid. This material was repurified by reverse-phase hplcto give the product (0.210 g, 55%) as a light yellow solid. ir (KBr) #max : 3400 (br, -OH), 1755 (ss-lactam CO), 1590 (-CO2-) cm-1 ; Hnmr (D2O) # : 8.60-7.76 (m, 4H, aromatic), 4.76 (t, J=5.8 Hz, 2R, N-CR2), 4.13 (d of q, J=J'=6.3 Hz, 1 H, H-i'), 3.95 (d oft, J=9.0 Hz, J'=2.8 Hz, 1 H, H-5), 3.45-2.75 (m, 5H), 2.59 (s, 3H, S-Me), 1.20 (d, J=6.4 Hz, 3H, CR Me); uv (H2O) Ajax: 296 (s8509), 273 (#13005), 23 (#11576) nm ; t@@ (pH 7.4, 3.68 C) 20 h.

Example 10 Preparation of 3- [2 - (1- (2,6 - dimethylpyridinium) ethylthio]-6&alpha;-[1-(R)-hydroxyethyl]-7-oxo-1- azabicyclo(3.2.0)hept-2-ene-2-carboxyalte

A. 1- (2 - mercaptoethyl) - 2,6 - dimethylpyridinium methanesulfonate

A mixture of 2,6-dimethylpyridine (19.2 mL, 0.165 mol) was stirred for 15 min,treated with ethylene sulfide (4.17 mL. 0.070 mol) and stirred at 100 C for 42 h under a nitrogen atmosphere. After cooling to 250C, the reaction mixture was diluted with ether (45 mL) and water (30 mL). The two layers were separated and the organic layer was extracted with water (2 x 5 mL).The aqueous layers were combined, filtered through a Ceiite pad, washed with ether(2x 15 mL), pumped to remove the traces of organic solvents and poured on top of a column (3.0 x 12 cm) of p-bondapak C-18. Elution with 3% acetonitrile 97% water mixture gave after lyophylization of the appropriate fractions 2.5 g ofthe impure title compound as syrup.Itwas repurified by hplc (l-bondapak C-i 8) to give 0.90 g (7% ) of thetitle compound. ir (film) vmax: 2520 (SH), 1640 and 1625 (pyridinium), 1585,1490,1200 cm-1 (sulfonate) 1Hmr (DMSO-d6 + D2O) 5: 2.36 (3H, s, CH3SO3-) ; 4.62 (2H, m,l CH2N+), 7.74 (2H, M, Hm of Pyridinium), 8.24 (1H, m, Hp of pyridinium), uv (H2O) max : 272 (4080) mil.

B. Paranitrobenzyl3-[2 - (1 - (2,6-dimethylpyridinium))ethylthio 6&alpha; - [1 - (R) - hydroxyethyl] -7 - oxo azabicyclo(3.2.0)hept - 2 - ene - carboxylate dipheny Iphosphate

To a cold (0 C) solution of p-nitrobenzyl 6&alpha; - [1 - (R) hydroxyethyl] - 3,7 - dioxo - 1 azabicyclo(3.2.0)heptane - 2 - carboxylate (0.658 g, 1.89 mmol) in acetonitrile (6 mL) undera nitroge atmosphere was added diisopropylethylamine (0.394 mL, 2.26 mmol) and diphenyl chlorophosphate (0.468 mL, 2.26 mmol).The reaction mixture was stirred 30 min and treated with a solution of 1 - (2 - mercaptoethyl) - 2,6 - dimethylpyridinium methanesulfonate (0.720 g, 2.73 mmol) in acetonitrile (3 mL) followed by diisopropylethylamine (0.394 mL, 2.26 mmol). The reaction mixture was stirred at 00C for 2 h, diluted with cold (0 C) water (27 mL) and poured on top of a column (2.5 x 9.0 cm) of -bndapak C-18.Elution with acetonitrile water mixtures and lyophylization of the appropriate fractions gave 0.92 g (65%) ofthetitle compound, ir (KBr) vmax: 3700-3000 (OH), 1765 (C=O of ss-lactam), 1690 (C=O) of PNB ester), 1620 (pyridinium), 1590 (phenyl), 1517 (NO2), 1330 (NO2), 880 cm-1 (NO2), Hmr (DMSO, d6) 5:1.15 (3H, d,J=6.2 Hz, CH3CHOH), 2.7-3.7 (11H, CH2S, 2-CH3 on pyridinium, H-4, H-6), 3.7-4.4 (2H, C3CHOH, H-5), 4.7 (2H, m,CR2N+), 5.14(1 H, d, J=4.5 Hz, OH), 5.37 (center of ABq, J=13.2 Hz, CR2 of PNB), 6.-7.5 (10H, m phenyl), 7.5-8.7 (7H, pyridinium, H's of PNB), uv (H2O) Anal: 274(E14150),319(A9445) mu.

C. 3-[2-(1-(2,6- dimethylpyridinium)ethylthio] 6ss-[1-(R)-hydroxyethyl]-7-oxo1azabicyclo(3.2.0)hept-2-ene-2-carboxylate

To a solution of p-nitrobenzyl 3 - [2 - (1 - (2,6- dimethylpyridinium)]-ethylthio]-6&alpha;-[1-(R)- hydroxyethyl - 7 - oxo - 1 - azabicyclo(3.2.0)hept - 2 ene - 2 - carboxylate diphenylphosphate (0.80 g, 1.07 mmol) in wettetrahydrofuran (42 mL) was added ether (42 mL), potassium phosphate monobasicsodium hydroxide buffer (0.15M, pH 7.22,21 mL) and 10% palladium on charcoal (0.80 g). Theresulting mixture was hydrogenated for 1 h under 40 psi at 23 C and filtered through a Celite pad.Thetwo layers were separated and the organic layer was extracted with the buffer (3 x 8 mL).The aqueous phase were combined, washed with ether (50 mL), pumped to remove traces of organic solvent and poured on top of a column (3.0 x 10.2 cm) of u-bondapak C-i 8.

Elution of the column with 5% acetonitrile-95% water mixture and lyophylization ofthe appropriate fractions gave the title compound 0.246 g (63%) as a yellowish powder, ir(KBr) vmax: 3700-2800 (OH), 1750 (C=O of the #6-lactarn), 1620 (pyridinium), 1585 cm-1 (carboxylate), 1Hmr (D2O) o: 1.23 (3H, d, J=6.4 Hz, CH3CHOH), 2.5-3.5 (11H, H-4, H-6, CH2S, 2CH3 on pyridinium), 3.8-4.4 (2H, CH3CHOH, H-5), 4.5-4.9 (CH2N+, HOD), 7.64 and 7.74 (2H, A part of A2B system, Hm of pyridinium). 8.07, 8.16, 8.18 and 8.27 (1 H, B part of A2B system, Hp of pyridinium), uv (H2O) Ajax: 277 (E9733), 300(E8271) mu, [&alpha;]D + 50.7 (C 0.48m H-2O),Anal. calcd. for C18H22N2O4S.1.5 h2O: C 55.51,H 6.47, N 7.19; found: C 55.14, H 6.23, N 6.46.

Example 11 Preparation of(5R,6S) - 3 - [2 - (2 - methylthio - 3 methylimidazolio)ethyl-thio]-6-[1-(R)-hydroxyethyl - 7 - oxo - 1 - azabicyclo[3.2. O]hept - 2 - ene - 2 carboxylate

A. 2 - Methylthio - 3 - methyl - 1- (2 - mercaptoethy1)imidazolium trifluoromethanesulfonate

trifluoromethanesulfonic acid (1.38 mL, 0.015 mol) was added dropwiseto 2 - methylthio - 1 methylimidazole1 (4.0 g), 0.03 mol) at 0 C under N2.

Ethylene sulfide (0.9 mL, 0.015 mol) was then added and the mixture was heated at 55 C under N2 for 24h.

The reaction mixture was tritu rated with ether (3x) and the residue was taken up in acetone, filtered and evapoarted.This gavethe product (4.2 g, 82%) ; as a semi-crystalline solid which was used as such withoutfurther purification. ir(film) vmax: 2550 (w, sh) cm-1 ; 1Rnmr (d6-acetone) 5: 7.97(s, 2H), 4.66 (t, J=7 Hz, 2H, methylene),4.17 (s, 3H, N-Me), 3.20 (d oft, J=7 Hz, J'=9 Hz, 2H, methylene),2.72 3H, S-Me), 2.20 (t, J=9Hz, 1H, -SH).

1. Prepared as per A. Wohl : and W. Marckwald, Chem. Ber. 22, 1353 (1889).

B. p-Nitrobenzyl (5R. 6S)-3-[2-(2-methylthio-3methylimidazolio)ethylthio]-5 6-[1 - (R) - hydroxy ethyl) - 7- oxo - 1- azabicyclo[3.2.0]hept-2-ene-2- carboxylate diphenylphosphate

To a solution of p-nitrobenzyl (5R, 6S) - 6 - [1 - (R) - hydroxyethyl] - 3,7 - dioxo - 1 azabicyclo[3.2.0]heptane -2 - carboxylate (1.40 g, 4.0 mmol) in 50 mL of dry acetonitrile. atO C under N2, was added dropwise diisopropylethylamine (0.76 mL, 4.4 mmol) followed by diphenyl chlorophosphate (0.91 mL,4.1 mmol).Afterstirringthe reaction mixture at room temperature for 1 h, diisopropylethylamine (0.76mL,4.4 mmol) was added andthen a solution of 2 - methylthio - 3 - methyl - 1 - (2 mercaptoethyl)imidazolium trifluoromethanesulfonate (2.0 g, 5.9 mmol) in 5 mLof acetonitrile was added dropwise. The reaction mixture was kept at room temperature for 1.5 h and was then concentrated in vacuo to give a gum. This gum was taken unpin H2O and applied to a C18 reverse-phase column.Elution with H2O, then 20% acetonitrile-H2O and finally 30% acetonitrile-H2O, followed by lyophilization of the appropriate fractions afforded the product (0.90 g, 30%) as a light yellow solid. ir(KBr) vmax: 3380 (br, OH), 1770 (ss-lactam CO)cm-1 ; Hnmr (d6-acetone) # : 8.35 (br, s,1 H), 8.24,7.78 (AB q, J=8.8 Hz, 4H, aromatic), 7.89 (br, s,1 H), 7.25-6.91 (m, 1 OH, diphenylphosphate), 5.50, 5.25 (ABq, J=12Hz, 2H, benzylic), 4.75-4.27 (m,3H),4.03 (s,3H, N-Me), 4.15-2.75 (m, 3H), 2.59 (s, 3H, S-Me), 1.22 (d, J=6.2 Hz, 3H, - CHMe).

C. (5R,6S) -3-[2- (2- Methylthio -3- methylimidazo- lio)ethyl- thio]-6-[1-(R) -hydroxyethyl]- 7-oxo- 1 azabicyclo[3.2.0]hept- 2 - ene - 2 - carboxylate

To a solution of p-nitrobenzyl (5r, 6s)- 3 - [2 - (2 methylthio-3- methylimidazolio)ethyl thio]-6-[l- (R) - hydroxyethyl] -7 - oxo - 1 - azabicyclo[3.2.0]hept- 2- ene -2 - carboxylate diphenylphosphate (1.20 g, 1.56 mmol) in a mixture of 70 mLofTRF,70 ml of ether and 31 mL of phosphate buffer (0.05 M, pH 7.4) was added 1.2 g of 10% palladium-on-charcoal. This mixture was hydrogenated (Parr) at 35 psi for 55 min.

The reaction mixture was then filtered through Celite and the filter cake was washed with H2O and ether.

The aqueous phase was separated, cooled at 0 C and the pH was adjusted to 7.0 with saturated aqueous NaHCO3. After removing residual organic solvents in vacuothe aqueous solution was applied to a C18 reverse-phase column. Elution with H2O and then 8% acetonitrile-H2O and subsequent lyophilization ofthe relevant fractions gave 0.25 g of a solid.This material was repurified by reverse-phase hplcto give the product (0.114g, 19%) as an off-white solid, ir(KBr) #max : 3420 (OH), 1750 (ss-lactam CO), 1590 (-CO2#) cm-1 ; Hnmr (D2O) # : 7.58 (s, 2H), 4.52 (t, J=6Hz, 2H), 4.28-3.82 (m, 2H), 3.90 (s, 3R, N-Me), 3.40-2.87 (m, 5H), 2.40 (s, 3H, S-Me), 1.20 (d, J=6.4 Hz, 3H, - CHMe) ; uv (H2O) #mx : 297 (#7572), 262 (#6259), 222 (#7955) nm.

Example 12 Preparation of (5R, 6S) - 3 - [2 - (3 - aminopyridinio)ethyl-thiol-6-[1-(R)-hydroxyethyl]-7-oxo-1azabicyclo[3.2.0]-hept-2-ene-2-carboxylate

A. 3-Amino-i- (2 - mercaptoethyl)pyridinium chloride

3 -Aminopyridine (1.50 g, 0.016 mol)wastaken up in 15 mL of 1 # methanolic HCI and the resulting solution was evaporated to give the hydrochloride as an oil. To this oil was added 3-aminopyridine (1.32 g, 0.015 mol) and ethylene sulfide (0.89 ml, 0.015 mol) and the resulting mixture was heated (oii bath) at 60-65 C under N2 for 2 h. Another equivalent of ethylene sulfide (0.89 ml, 0.015 mol) was added and heating was continued at 55-65 C for 65# h.The reaction mixture was washed with CH2Cl2 : and then taken up in H2O (25 ml). The aqueous solution was applied to a C18 reverse-phase column which was eluted with H2O. Evaporation ofthe relevantfractions gave the product (1.26 g, 44%) as a colorless, viscous oil. ir(film) vmax: 3180 (NH2) cm-1 Hnmr (d6-DMSO) o: 8.19-7.59 (m, 4H, aromatic), 4.59 (t, J=6.2 Hz, 2H, N-CH2) ; 3.5 (brs, 2H-NH2), 3.20-2.77 (m, 3H0, B. p - Nitrobenzyl(5R,6S) - 3 - (2 - (3 - aminopyridi- nio)ethyl-thio)-6-(1-(R)-hydroxyethyl)-7-oxo-1azabicyclo(3.2.0)-hept-2-ene-2-carboxylate diphenylphosphate

To a solution of p-nitrobenzyl (R, 6S) - (1 - (R) - hydroxyethyl) - 3,7 - dioxo - 1 azabicyclo(3.2.0)heptane - 2 - carboxylate (0.696 g, 2.0 mmol) in 10 mL of dry acetonitrile. atO C inder N2, was added dropwise diisopropylethylamine (0.382 m L, 2.2 m mol) followed by diphenyl ch lo rophosphate (0.457 mL, 2.2 mmol).After stirrng at 0 C for 30 min. a solution of 3 - amino - 1 - (2 - mercaptoethyl)pyridinium chloride (0.475 g, 2.5 mmol) in 1 ml of dry DMF was added, followed by additional diisopropylethylamine (0.435 mL,2.5 mmol).The reaction mixture was kept at 0 C for 1.5 hand was then concentrated in vacuo. The resulting gum was taken up in acetonitrile-H2O (1:1) and applied to a C18 reverse-phase column. Elution with H2O,followed by 20% acetonit rile-H2O and subsequent lyophilization ofthe relevant fractions afforded the product (0.730 g, 50%) as a beige-colored solid. ir(KBr) vmax: 3330 (br, OH), 3180 (br, NH2), 1770 (ss-lactam CO), 1690 (-CO2PNB) cm-1 Hnmr (d6-DMSO) # : 8.29-7.63 (m, 8 aromatic), 7.2-6.7 (m, 1 OH, diphenylphosphate), 5.47,5.18 (AB q, J=14 Hz, 2H, benzylic), 4.73-4.45 (m, 3H), 4.2-3.8 (m,1H),3.6-2.6 (m, 8H), 1.15 (d, J=6.2 Hz, 3H, CHMe).

C. (5R, 6S)-3-(2-(3-aminopyridinio)ethylthio)-6-(1 -(R)-hydroxethyl)-7-oxo-1-azabicyclo(3.2.0)hept2-ene-2-carboxylate

To a mixture of p - nitrobenzyl (5R, 6S) - 3 - (2 - (3 aminopyridinio)ethyl thio) - 6 - (1 - (R) - hydroxyethyl) -7-oxo-1-azabicyclo(3.2.)hept-2-ene-2 carboxylate diphenyiphosphate (0.730 g, 1.0 mmol) and 10% palladium - on - charcoal (0.7 g) in 25 mL of a phosphate buffer (0.05 M, pH 7.4) was added 8 mL of THFand 20 mL of ether. This mixture was then hydrogenated (Parr) at 40 psi for 1 h. The resulting mixture was filtered through a pad of Celite and the filter cake was washed with H2O and ether. The aqueous phase was separated, washed with ether (2 x) and then residual volatiles were removed in vacuo.

The aqueous solution was immediatelyappliedto a C18 reverse-phase column which was eluted with H2O. Lyophilization ofthe relevant fractions afforded 0.45 9 of an off-white solid. This material was repurified by reverse-phase hplcto give the desired product (0.123 g, 35%) as an ivory-colored solid.

ir(KBr)#max : 3340 (br), 1750 (br, ss-lactam CO), 1580 (br, -CO2#) cm-1 ; Hnmr (D2O) # 8.07-7.59 (m, 4H, aromatic), 4.61 (t, J=5.8 Hz, 2H, N-CH2), 4.14 (d of q, J=J'=6.3 Hz, 1 H, H-1 '), 3.97 (d oft, J=9.2 Hz, J' =2.6 Hz, 1H, H-5), 3.38 (t, J=5.8 Hz, 2H, S-CH2) 3.24 (d of d, J=6.0 Hz, J'=2.6 Hz, 1 H, H-6), 3.17-2.57 (m, 2H, H-4), 1.21 (d, J=6.3 Hz, 3H, CHMe); uv (H2O)#max : 299 (#79490, 256 (#8822) nm ; t1/2 (pH 7.4, 36.8 C0 18.5 h.

Example 13 PREPARATION OF

(5R, 6S) 3 - [1 - (S) - methyl - 2 - (1 - pyridinium)ethylthio]-6-1-(R)-hydroxyethyl]-7-oxo-1azabicyclo(3.2.0)hept - 2 - ene - 2 - carboxylate and

(5R, 1,6S)3-[1-(R)-methyl- 2 - (1 - pyridinium)ethyl- thio]-6-[1-(R)-hydroxyethyl]-7-oxo-1 -azabicyclo(3.2.0)hept - 2 - ene - 2 - carboxylate A. dl-1-(2-mercapto-2-methylethyl)pyridinium methanesulfonate dl - 1- (2 - mercapto - 1methylethyl)pyridinium methanesulfonate

Methanesulfonic acid (1.95 mL, 0.030 mol) was added slowlyto cold pyridine (7.83,0.097 mol) and the resulting mixture was stirred at 400C for 15 min, treated with dl - propylenesulfide (2.59 mL, 0.033 mol) and stirred at60 C under a nitrogen atmosphere for 90 h. Pyridinewas removed undervacuum;the residue was mixed with water and purified by chromatography (hplc, Prep. Bondapak C-18).The appropriate fractions were combined and lyophilized giving dl - 1 - (2 - mercapto -2 - methyl ethyl)pyridinium methanesulfonate 1.149 (15%) as a colorless syrup; ir (film) vmax: 2520 (SH), 1640 (pyridinium), 1180 (s, CH3SO3-), 1040 (CH3SO3-) cm-1, Hmr (DMSO d6) 5:1.35 (d, J=6.8 Hz,3H, CH3CHS0, 2.30 (s, 3H, CH3SO3-), 2.90 (d, J=8.5 Hz, 1H, SH), 3.2-3.7 (m, CHSH), 4.52 (dd, Jgem=12.9 Hz, J=8.4 Hz, CHCH2N+), 4.87 (dd, Jgem=12.9 Hz, J=6.0Hz, CHCH2N+), 8.0-8.4 (m, 2H, Hm of pyridinium), 8.5-8.8 (m, 1H, Hp of pyridinium), 9.04 (dd, J=1.4 Hz, J=6.7 Hz, 2H, Ho of pyridinium), uv (R2O) Ajax: 208 (s5267), 259 (s3338), Anal. calcd. for C9H15NO3S2-2H2O ; C 37.88, H 6.71, N 4.91,S22.47; found:C 37.49, H 6.85, N 4.86, S 22.09 and dl - 1 - (2 - mercapto - 1 - methylethyl) pyridinium methanesulfonate 0.82 g (11%) as a colourless syrup; ir (film) vmax: 2500 (SH),1628 (pyridinium), 1180 (sulfonate, 1035 9sulfonate) cm-1, Hmr (DMSO d6) # : 1.69 (d, J=6.8 Hz, 3H, CH3CHN+), 2.31 (s, 3H, CH3SO3-), 3.0-3.3 (m, 2H, CH2S), 4.2-5.2 (m, 1H, CHN+), 8.0-8.4 (m, 2H, Hm of pyridinium), 8.5-8.8 (m, 1 H, Hp of pyridinium), 9.0-9.2 (m, 2H, Ho of pyridinium), uv (R2O) Ajax: 209 (#4987), 258 (E3838).

Anal. calcd. for C9H15NO3S2.1.5H2O : C 39.11, H 6.56, N 5.07 ; found : C39.13, H5.92, N5.20.

B. (5R, 6S0 paranitrobenzyl3-[1-(R,S)methyl-2-(1pyridinium)ethylthio]-6-[1-(R)-hydroxyethyl]-7oxo - 1 - azabicyclo(3.2. 0)hept-2-ene-2- carboxylate diphenylphosphate

40 To a cold (0 C) solution of (5R, 6S) paranitrobenzyl 6 -[1-(R)-hydroxyethyl]-3.7-dioxo-1azabicyclo(3.2.0)heptane - 2 - carboxylate (0.523 g, 1.5 mmol) in acetonitrile (6 mL) kept under a nitrogen atmosphere was added diisopropylethylamine (0.314 mL, 1.8 mmol) followed by diphenyl chlorophosphate (0.373 mL, 1.8 mmol). The reaction mixture was stirred for 30 min. and treated with a solution ofdl - 1 (2-mercapto-2-methylethyl) pyridinium methanesulfonate (0.539 g, 2.16 mmol) in acetonitrile (2 mL) and diisopropylethylamine (0.314 mL, 1.8 mmol).The reaction mixture was stirred at 0 C for 1 hr, diluted with cold (0 C) water (24 mL) and chromatographed over prep bondapak C-18 column (2.5 x 8.5cm) with 25-50% acetonitrile in water as eluting solvents to give 1.07 g (97% ) ofthe title compound as a yellowish powderafterlyophiliza- tion; ir(KBr) vmax: 3700-3100 (OH), 1770 (C=O of ss lactam), 1 695(C=O of PN B ester), 1630 (pyridinium), 1590 (phenyl), 1518 (NO20, 1348 (NO2), 885 (NO2) cm Hmr (DMSOd6) # : 1.14(d,J=6.1 Hz,3H, (CH3CHO), 1.33 (d, J=6.3 Hz, 3H, CH3CHS), 4.6-5.0 (m, CH2N+), 5.14 (d, J=5.2 Hz, 1H, OH), 5.37 (center of ABq, J=12.4 Hz, 2H, CH2 of PNB), 6.6-7.5 (m, 10H, phenyl of phosphate), 7.69 (d, J=8.7 Hz, 2H, Ho of PNB), 8.0-8.4 (m, 4H, Hm of PNB, Hm of pyridinium), 8.4-8.8 (m, 1H, Hp of pyridinium), 9.07 (d, J=5.6 Hz, 2H, Ho of pyridinium), uv (H2O) Ajax: 263 (s1332S), 308 (#8915). Anal. calcd. for C36H36N3O10SP.H2O : C57.52, H 5.10, N 5.59, S4.27 ; found : C 57.76, H 4.96, N 5.36, S 4.35.

C. (5R, 6S)3-[1 - (R andSJ - methyl - 2 - (1 -pyridinium) ethylthiol- 6- [1-(R)- hydroxyethyl]- 7- oxo - 1azabicyclo(3.2.0)hept-2-ene-2-carboxylate

To a solution of (5R, 6S) paranitrobenzyl 3 - [1 - (R, S)methyl-2-(1-pyridinium)ethylthio]-6-[1-(R) hydroxyethylj - 7 - oxo - 1 - azabicyclo - (3.2.0)hept- 2 ene- 2 - carboxylate diphenylphosphate (0.60 g, 0.82 mmol) in wettetrahydrofuran (33 mL) was added ether (33 mL), potassium phosphate mono basic sodium hydroxide buffer(17 mL, 0.15N, pH 7.22) and 10% palladium on charcoal (0.60 9).The resulting mixture was hydrogenated for 1 h under 40 psi at 23 C. The two layers were separated and the organic layerwas extracted with water (3 x 7 mL). The aqueous layers were combined, filtered through a Celite pad, washed with ether (3 x 20 mL) and chromatographed on prep bondapak C-18 column (2.5 x 9.5 cm) with water as eluting solvent to give 0.18 9 (63%) of mixture of diastereoisomers.The two diastereoisomers were separated by hplc (prep bondapak C-18) with water as eluting solvent: isomer with lower retention time, 0.068 g (23%) compound "B", ir (KB) #max : 1770 (C=O of ss-lactam), 1633 (pyridinium), 1593 (carboxylate) cm-1,1 Hmr (D2O) 5: 1.20 (d, J=6.3 Hz, 3H, CH3CHO), 1.42 (d, J=6.9 Hz, 3H, CH3CHS),2.3-3.2 (m, 3H, H-4, H-6), 3.5-3.9 (m, 1H, SCH), 3.9-4.2 (m, 2H, H-5, CH3CHO), 4.3-5.1 (m, CH2N+), 7.8-8.2 (m, 2H, Hm of pyridinium), 8.4-8.7 (m, 1 H, Hp of pyridinium), 8.7-9.0 (m, 2H, Ho of pyridinium) uv (H2O) Ajax:: 260 (#6727), 300 (s8245), [&alpha;]D - 39.3 (c, H2O), T1/2=1.26 h (measured at a concentration of 10-4M in phosphate buffer pH 7.4 at 36.8 C) ; isomer with higher retention time, 0.081 9 (28%), compound "A", ir (KBr) Vmax : 1755 (C=O of ss-lactam), 1630 (pyridinium), 1590 (carboxylate) cm-l, 1Hmr (D2O) # : 1.18 (d, J=6.3 Hz, 3H, CH3CHO), 1.40 (d, J=7.0 Hz, 3H, CH3CHS), 2.84 (d, J=9.3 Hz, 2H, H-4), 3.26 (dd, J=2.7 Hz, J=5.9 Hz, 1 H, H-6), 3.4-4.2 (m, 3H, SCH, CH3CHO, H-5), 4.2-5.1 (m, CH2N+), 7.7-8.1 (m, 2H, Hm of pyridinium), 8.3-8.65 (m, 1H-, Hp of pyridinium), 8.65-8.9 (m, 2H, Ho of pyridinium), uv (H2O) #max : 259 (#5694), 296 (#6936), [&alpha;]D +96.9 (c 0.56, H2O), T1/2 \ 15.6 h (measuured at a concentra tion of 10-4 M in phosphate buffer pH 7.4 at 36.8 C).

Example 14 PREPARATION OF

(SR,6S)-[2-(S)-1 -pndinium)]-1 -(S)- cyclohexylthio] - 6 - [1 - (R) - hydroxyethyl] - 7 - oxo - 1 azabicyclo(3.2.0)hept - 2 - ene - 2 - carboxylate and

(5R.6S)3-[2-[(R)-(1-pyridinium)]-1-(R)cyclohexylthio] - 6 - [1-(R)- hydroxyethyl] - 7 - oxo - 1 azabicyclo(3.2.0)hept-2-ene-2-carboxyalte.

A. dl - 1- (2 - mercapto - 1- cyclohexyl)pyridinium methanesulfonate

Methanesulfonic acid (0.65 mL, 0.01 mol) was added dropwise to pyridine (2.42 mL,0.03 mol) with cooling. The mixture was stirred under a nitrogen atmosphere for 10 min. treated with dl-cyclohexene- sulfide (1.377 g (85% pure), 0.0102 mol) and stirred at 72 C for 25 h. The excess of pyridine was removed undervacuum and the traces were codistilled with water. The residuewas mixedwith water and chromatographed through prepbondapak C-18 column (5 x 13 cm) with 0-2% acetonitrile in water as eluting solvent giving after lyophilization a colourless syrup 1.57 g (53%), ir (film) Vmax : 2500 (SH), 1625 (pyridinium). 1190 (SO3), Hmr (DMSO d6) # : 1.2-2.5 (m, 8H, cyclohexyl H), 2.32(s, 3H, CH3SO3-), 2.82 (d, J=9.8 Hz, SH), 3.0-3.5 (m, 1H, CHSH0, 4.2-4.9 (m, 1H, CHN+0, 8.0-8.3 (m, 2H, Hm of pyridinium), 8.4-8.8 (m, 1 H, Hp of pyridinium), 8.9-9.3 M, 2H, Hoof pyridi nium), uv (H2O) #max : 214 (#5365), 258 (#3500).

anal. calcd. for C12H19NO3S2. H2O : C 46.88, H 6.88, N 4.56; found: C46.61, H 6.46, N 4.65.

B. (5R, 6S) paranitrobenzyl 3-[2-(Ror S)-(1pyridinium)]- 1 - (R or S) - cyclohexylthio - 6- [1 - (R) hydroxyethyl]- 7- oxo - 1- -azabicyclo(3.2.0)hept-2- ene -2- carboxylate diphenylphosphate

To a cold (0 C) solution of (5R,6S)pa ra n itro benzyl 6 -[1-(R)-hydroxyethyl]-3,7-dioxo-1 -azabicyclo(3.2.0)heptane-2-carboxyalte (1.37 g, 3.93 mmol) in acetonitrile (15 mL) kept under a nitrogen atmosphere was added diisopropylethylamine (0.822 mL, 4.7 mmol) and diphenyl chlorophosphate (0.979 mL,4.7 mmol).The resulting solution was stirred for 30 min and treated with a solution of dl - 1 - (2 - mercapto - 1 - cyclohexyl)pyridinium methanesulfonate (1.649,5.66 mmol) in acetonitrile (4.7 mLfollowed by diisopropylethylamine (0.822 mL, 4.7 mmol).The reaction mixture was stirred at 0 C for 1 hr, diluted with cold (00C) water (75 mL) and chromatographed on prepbondapak C-18 with 2550% acetonitrile in water as eluting solvent giving after lyophilization of the appropriate fractions 1.9 9 (53%) of the title compound, ir (KBr) vmax: 3700-3000 (OH), 1770 (C=O of ss-;actam), 1700 (C=O of PNB ester), 1628 (pyridnium), 1590 (phenyl), 1515 (NO2), 1345 (NO2), 880 (NO2) cm-1, Hmr (D2O) # : 1.13 (d, J=6.1 Hz, 3H, CH3CHO), 1.2-2.5 (m, 8H, cyclohexyl H), 2.7-3.5 (m, 4H, H-4, H-6, CHS), 3.5-4.4(m, 2H, CH3CHO, H-5), 4.4-5.0 (m, 1H, CHN+), 5.30 (center of ABq, 5=12.8 Hz,CH2 of PNB), 6.7-7.4(m, 10H, phenyl), 7.65 (d, J=8.6 Hz, 2H, Ho of PNB), 7.9-8.4 (m, 4H, Hm of PNB, Hm of pyridinium), 8.4-8.8 (m, 1 H, Hp of pyridinium), 9.0-9.4(m, 2H, Ho of pyridinium), uv (H2O) #max : 263 (E9038, 309 (E6394).Anal. calcd for C39H40N3O10SP. H2O: C 59.16, H 5.35, N 5.31;found: C 58.95, H 5.15, N 5.57.

C. (5R, 6S)3-[2-[(R or S)-(1 -pyridinium)]- 1 -(Ror S)-cyclohexylthio]- 6-[1 - (A) -hydroxyethyl]- 7- oxo -1-azabicyclo(3.2.0)hept-2-ene-2-carboxyalte

To a solution of (5R,6S) paranitrobenzyl 3 - [2 - [(R or S) - (1 - pyridinium)] - 1 - (Ror S) - cyclohexylthio] - 6 [1-(R)-hydroxyethyl]-7-oxo-1azabicyclo(3.2.0)hept - 2 - ene - 2 - carboxylate diphenylphosphate (1.85 g, 2.34 mmol) in wettetrahydrofuran (96 mL) was added ether (96 mL), potassium phosphate monobasic-sodium hydroxide buffer (0.15M, pH 7.22,50 mL) and 10% palladium on charcoal (1.9 9). The resulting mixture was hydrogenated at 23 under 40 psi for 1.25 h. The organic layer was separated and washed with water (3 x 20 mL).

The aqueous solutions were filtered through a Celite pad,washedwith ether (2x60 mL), pumped to remove the traces of organic solvents and chroma- tographed on prepbondapak C-18 column (4.5 x 9 cm) with 0-5% acetonitrile in water as eluting solvent giving after lyophilization 0.705 9 (76%) of a mixture of disastereoisomers.The separation of the disastereoisomers was done by hpic (prepbondapak C-18) with 4% acetonitrile in water as eluting solvent; diastereoisomerwith lower retention time, compound "A", (0.29 g, 31%), ir (KBr) vmax: 1750 (C=O of '3-lactam), 1620 (sh, pyridinium), 1685 (carboxylate cm, Hmr (D2O) # : 1.21 (d, J=6.3 Hz, 3H, CH3CHO), 1.4-2.5 (m, 8H, cyclohexyl H), 2.5-3.05 (m, 2H, H-4), 3.05-3.25 (m, 1 H, H-6), 3.3-3.7(m, 1 H, CHS), 3.9-4.3 (m, 2H, H-5, CH3CHO), 4.3-4.8 (m, CHN+), 7.8-8.2 (m, 2H, Hm of pyridinium), 8.3-8.7 (m, 1 H, Hp of pyridinium), 8.8-9.1 (m, 2H, Ho of pyridinium), uv (H2O) #max : 260 (#7123), 300 (#8685), [&alpha;]D +6.2 (c 0.63, R2O),T112 = 16.6 h (measured ata concentration of 10-4 M in phosphate buffer pH 7.4 at 36.8 C0 ; Anal.

calcd. for C20H24N2O4S. 2H2O : C56.59, H 6.65, N 6.60, S 7.55; found: C 56.83, H 6.47, N 6.59, S 7.43; diastereoisomerwith higher retention time, compound "B", (0.35 g, 38%) ir (KBr) vmax: 1750 (C=O of ss-lactam), 1622 (sh, pyridinium), 1588 (carboxylate) cm-1, Hmr (D2O) 5:1.19 (d, J=6.4Hz, 3H, CH3CHO), 1.3-2.5 (m, 8H, cyclohexyl H), 2.5-3.1 (m, 2H, H-4), 3.1-3.3 (m, 1H, H-6), 3.3-3.8 (m, 2H, H-5, CHS), 4.1 (center of m, 1H, CH3CHO), 4.25-4.7 (m, 1H, CHN+), 7.8-8.1 (m, 2H, Hm of pyridinium), 8.3-8.7 (m, 1 H, Hp of pyridinium),8.75-9.0 (m, 2H), Ho of pyridinium), uv (H2O) #max :: 259 (#5992), 296 (#7646), [&alpha;]D # + 65.3 (c 0.43, H2O), t112 = 20.2 h (measured at a concentration of 10-4 M in phosphate buffer pH 7.4 at 36.8 C).

Example 15 A. (5R)Allyl3-[(2-pyridinioethyl)thio]-(6S)-[(1R)hydroxyethyl]-7-oxo-1-azabicyclo(3.2.0)hept-2ene - 2 - carboxylate diphenylphosphate

To a solution of (5R) allyl 3,7 - dioxo - (6S) - [(1 R) - hydroxyethyl] - 1 - azabicyclo(3.2.0)heptane - (2R) carboxylate (473 mg, 1.87 mmol) in CH3CN (6 mL) was added at ca. -10 C under a nitrogen atmosphere diisopropylethylamine (0.42 mL, 2.4 mmol) followed by diphenyl chlorophosphate (0.50 mL, 2.4 mmol).

The mixture was stirred at 0 C for 30 min. and then cooled to - 15 C. To this was added an oily suspension of N - (2 - mercaptoethyl) - pyridinium chloride (527 mg, 3.00 mmol) in CH3CN (1 mL) containing 5 drops of DMF, followed by diisopropylethylmine (0.42 mL, 2.4 mmol). The mixture was stirred at-15 for 30 min. and then diluted with H2O (20 mL). This mixture was directly purified on a reverse phase silica gel (C18 PrepPAK, 12 g, Waters Associates) eluting with H2O (200 mL), 10% CH3CN/H2O (100 mL) 20% CH3CN/H2O (100 mL), 30% CH3CN/H2O (100 mL) and then 40% CH3CN/H2O (100 mL).

Appropriate fractions were collected, the organic solvent removed by a vacuum pump and lyophilized to obtain 786 mg (1.26 mmol, y, 67.3%) of the title compound as brownish powder: Hmr (DOS-d6, CFT-20) o: 1.6 (3H, d, J=6 Hz, 1'-CH3) 2.6-3.7 (m), 3.75-4.3 (2H, m,5-H ns 1 '-H), 4.65 (2H, m, CO2CH2-), 4.87 (2H, t, J=6Hz, -CH2N'),5-6.2 (3H, m, olefinic protons), 6.6-7.4 (m, aromatic protons), 8.15 (2H, "t", J=7Hz, aromatic protons metato the nitrogen),8.63 H, #, "t" J=, aromatic proton para to the nitrogen) and 9.07 ppm (2H, "d", J~7 Hz, aromatic protons ortho to the nitrogen); ir (film) v: 3400 (OH), 1770 (ss-lactam), 1690 (ester), 1625 (pyridinio).

B. (5R3-[(2-pyridinioethyl)thio]-(6S)-[(1R)hydroxyethyl] - 7- oxo -1- azabicyclo (3.2.0) hept-2- ene-2-carboxylate.

To a solution of (5R) allyl 3-[(2-pyridinioethyl thio]-(6S)-[(1R)-hydroxyethyl]-7-oxo-1azabicyclo (3.2.0) hept- 2 - ene - 2 - carboxylate diphenylphosphate (156 mg, 0.25 mmol) in CH3CN (2 mL) was successively added at ca. 22 C a solution of potassium 2 - ethylhexanoate in EtOAc (0.5 M, 0.6 mL; 0.3 mmol),triphenylphosphine (15 mg. 0.057 mmol) andtetrakistriphenylphosphinepalladium (15 mg, 0.013 mmol). The mixture was stirred at ca. 220C under a nitrogen atmosphere for 2 h. After addition of anhydrous Et2O (7 mL), the precipitate was filtered, washed with anhydrous Et2O (7 mL) and dried in vacuo to yield 101 mg of brownish solid. This was purified by reverse phase column chromatography (C18 PrePAK, 12 g, Waters Associates) eluting with H2O.Appropriate fractions (fr. 7-12, each 20 mL) were collected and lyophilizedto obtain 53 mg (0.16 mmol, y. 64%) ofthe title compound as yellowish powder.

This material was contaminated with potassium diphenylphosphate and potassium 2-ethylhexano ate : Hmr (D2O, CF5-20) # : 0.80 (t, J=6.4 Hz, Me from ethylhexanoate), 1.21 (3H, d, J=6.3 Hz, 1 '-Me), 2.93 (2H, dd, J1-5=9Hz, Jgem-4Hz, 1-Hs), 3.28 (1H, dd, J6-1-6.2 Hz, J6-5=2.5 Hz, 6-H), 3.42 (2H, t, J=Hz, -CH2S), 3.98 (1H, td, J5-1=9 Hz, J5-6=2.5Hz, 5-H), 4.15(1 H, q, J=6.2 Hz, 1 '-H), 4.80 (2H, t, J=6.0 Hz, -CH2N+), 7-7.5 (m, phenyl protons from diphenyl phosphate), 8.03 (2H, m, Hm of pyridinium), 8.56 (1 H, m, Hp of pyridinium) and 8.81 ppm (2H, "d", J=6.5 Hz, Ho of pyridinium).

Example 16 Preparation of3 - [2 - (N - Methyl - thiomorpholinium) ethylthio]-6&alpha;-(1'-(R)-hydroxyethyl]-7-oxo-1- azabicyclo [3.2.0] - hept- 2 - ene - 2 - carboxylate

A. N - methyl - N - (2 - mercaptoethyl) thiomorpholinium methanesulfonate

To precooled (ice bath) N - methylthiomorpholine* (5.00 g, 42.7 mmol) was added methanesulfonic acid (1.47 mL, 20.5 mmol) and ethyl sulfide (1.30 mL, 21.4 mmol). The mixture was heated at 65 C for 24 h and diluted with water (25 mL). The aqueous solution was washed with diethyl ether (3 x 25 mL), pumped under vacuum and poured over a silica gel reverse phase column, the title compound being eluted with water.

The appropriate fractions were combined and evaporated to affordthethiol as an oil (4.80 g,yield 86%); ir (film) Vmax : 2550 cm-1 (w, SH0 ; Hmr (DMSO d6) # : 3.25-2.95 (6H, m, CH2N#), 3.32 (3H, s, CH3N#) ; 3.20-2.65 (7H, m, CH2S, SH) and 2.32 ppm (3H, s, CH3SO3) *J. M. Lehn and J. Wagner.Tetrahedron, 26,4227 (1970) B. para - Nitrobenzyl3 - [2 - (N - methyl - thiomorphonllium diphenylphosphate) ethylthiol] 6&alpha;-[1'-(R) -hydroxyethyl]- 7- oxo - 1 -azabicyclo [3.2.0] - hept-2 - ene - 2 - carboxylate

A cold (ice bath) solution of para-nitrobenzyl 6&alpha;; - [1 ' - (R) - hydroxyethyl] - 3,7 - dioxo - 1 - azabicyclo [3.2.0] heptane - 2 - carboxylate (557 mg, 1.60 mmol) in CH3CN (8 m L) was treated dropwise with diisopropyethyl amine (0.336 mL, 1.92 mmol) and dipheny Ichlorophosphate (0.400 mL, 1.92 mmol) and stirred for 30 min.The reaction mixturewas treated with N methyl - N - (2 - mercaptoethyl) thiomorpholinium methanesulfonate (803 mg, 2.29 mmol) in CH3CH (4 mL) anddiisopropylethyl amine (0.336 mL, 1.92 mmol) and stirred for 30 min. The solution was diluted with water (20 m L) and poured over a silica gel reversed phase column. The desired compound was eluted with a 50% acetonitrile-water mixture.The appropriate fractions were combined, pumped under vacuum for 2 hand lyophylized to afford the title compound (1.01 g, yield 85%) : ir (nujol) Vmax : 1760 (s, ss-lactam C=O) and 1510 cm-1 (s, NO2); 1Hmr (DMSO-d6) # : 8.25 (2H, d, J=8.8 Hz, H-aromatic), 7.70 (2H, d, J=8.8 Hz, aromatic), 7.33-6.84(10 H, H, m, H-aromatic), 5.37 (2H, center of ABq, J=14.2 Hz, CH2), 5.14(1 H, d, J=4.5 Hz, OH), 4.35-3.80 (2H, m, H-i'and H-5), 3.75-3.45 (6H, m, CH2N+), 3.31 (3H, s, CH3N+), 3.45-2.75 (9H, m, CH2S, H-6 and H-4) and 1.15 ppm (3H, d, J=6.2 Hz, CH3).

C. 3-[2-(N-methyl-thiomorpholinium)ethylthio] 6&alpha;-[1'-(R)-hydroxyethyl]-7-oxo-1- azabicyclo [3.2.0] - hept - 2 - ene - 2 - carboxylate

A solution of para-nitrobenzyl 3 - [2 - (N methylthiomorpholinium diphenylphosphate) ethyl thio]-6&alpha;-[1'-(R)-hydroxyethyl]-7-oxo-1- azabicyclo [3.2.01 hept - 2 - ene - 2 - carboxylate (1.31 g, 1.76 mmol) in 0.1 M pH 7.4 phosphate buffer (48.8 mL), tetrahydrofurgan (20 mL) and diethyl ether (20 mL)was hydrogenated over 10% pd/C (1.5 g) in a Parr shaker for 1 h at 40 psi. The reaction mixture was diluted with diethyl ether (40 mL) and the phases were separated.The organic phase was washed with water (2 x 5 mL). The aqueous phases were combined, filtered through a &num;52 hardened filter paper, washed with diethyl ether (2 x 20 mL) and pumped under vacuum. The aqueous solution was poured on a silica gel reverse phase column and the desired carbapenem was eluted with 5% acetonitrilewater.The appropriatefractions were combined, and lyophilized to give compound as an amorphous solid (205 mg, 31%); ir (nujol) vmax: 1750 (s, ss-lactam C=O) and 1590 cm-' (s, C=O); 1Hmr (D2O) 5: 4.25-3.95 (2H, m, h-i', H-5), 3.70-3.40 (6H, m, CH2N+), 3.35(1 H, dd, J=6.1 Hz, J=2.6 Hz, H-6), 3.08 (3H, s, CH3N+), 3.25-2.75 (8H, CH2S, H-4), and 1.24 ppm (3H, d, J=6.4 Hz, CH3) ; vu (H2O, c 0.062 (#max : 299 (#10,962) T1/2 17.7 h (0.1 M pH 7 phosphate buffer, 37 C).

Example 17 Preparation of 6R- 3 - [2 - (1- methylmorpholino) ethylthio]-6-[(R)-1-hydroxyethyl]-7-oxo1azabicyclo [3.2.0]hept- 2- ene - 2carboxylate

A. 1- Methyl - 1- (2 - mercaptoethyl) morpholinium trifluoromethanesulfonate

To N - methyimorpholine (3.29 mL, 0.030 mol) was added dropwisetrifluoromethanesulfonicacid (1.327 mL, 0.015 mol) at 10 C, followed by ethylene sulfide (0.89 mL, 0.015 mol). The resulting yellow-brown solution was heated (oil bath) at 50-60 C under N2 for 18 h. Volatile material was then removed in vacuo and the residual oil was taken up in 10 mL of H2O.The aqueous solution was washed with diethyl ether (3 x 5 mL) and then residual organic solvent was removed in vacuo. The resulting aqueous solution was applied to a C18 reverse-phase column which was eluted with H2Othen 5% acetonitrile-H2O and finally 10% acetonitrile-H2O. Evaporation ofthe revelantfractions afforded a white solid which was dried in vacuo (P2O5) to give the product (1.92 g, 41%). ir (KBr) Vmx : 2560 (-SH)cm ; Hnmr (d6-acetone) # : 4.25-3.6 (m, 8H), 3.49(s, 3H, N-Me), 3.35-2.7 (m, 5H).

B. p-Nitrobenzyl (5R, 6S)-3-[2- {1 - methylmorpho lino)ethylthio]-6-[(R)-1-hydroxyethyl]-7-oxo -1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate diphenylphosphate

To a solution of p-nitrobenzyl (5R,6S) - 6 - [(R) - 1 hydroxy] - 3,7 - dioxo - I - azabicyclo [3.2.0] heptane - 2-carboxyalte (0.348 g, 1.0 mmol) in 25 mL of dry acetonitrile was added dropwise diisopropylethylamine (0.181 mL, 1.1 mmol) and then diphenyl chlorophosphate (0;228 mL, 1.1 mmol) at 0 C@ under N2. After stirring at 0"C for 1 h diisopropylethylamine (0.226 mL, 1.3 mmol) was added to the resulting enol phosphate, followed by 1 - methyl - 1 - (2mercaptoethyl) morphoiinium trifluoromethanesulfonate (0.373 g, 1.2 mmol).The reaction mixture was stirred at room temperature for 1.5 h and then concentrated in vacuo. The residual material was taken up in H2O and applied to a C18 reverse-phase column. Elution with H2O then 20% acetonitrile-H2O and finally 30% acetonitrile-H20 followed by Iyophi- lization of the relevant fractions gave the product (0.360 g, 40%) ; as an amorphous solid. ir (film) 3300 (-OH), 1770 (ss-lactam CO), 1700 (-CO2PNB) cm-1 ; 1Hnmr (d6-acetone) 5: 8.25,7.80 (ABq, J=8.6 Hz, 4H, aromatic), 7.4-6.8 (m, 10H, diphenylphosphate), 5.56, 5.27 (ABq, J=14.2 Hz, 2H, benzylic), 4.42 9doft, J=9.2 Hz, J'=2,7 Hz, 1H, H-5), 4.1-2.7 (m, 17H0, 3.40 (3s, 3H, N-Me), 1.22 (d, J=6.2 Hz, 3H,-CHMe).

C. (5R, 6S) -3-[2- (1 -methylmorpholino) ethylthio] 6- 1(R) - 1 - hydroxyethyl] - 7 - oxo - 1 - azabicyclo [3.2.0]hept-2-ene-2-carboxylate

To a solution of p-nitrobenzyl (5R, 6S)- 3 - [2 - (1 methylmorpholino)ethylthio]-6-[(R)-1-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2carboxylate diphenylphosphate (0.360 g, 0.49 mmol) in 13 mLof phosphate buffer (0.05 M pH 7.4) was added 0.36 g of 10% palladium-on-charcoal, 20 mL of tetrahydrofuran and 20 mL of diethyl ether. This mixture was hydrogenated (Parr) at 32 psi for 1 h. The mixture was filtered through Celite and the filter pad was washed with H2O and diethyl ether.The aqueous phase was separated and the pH was adjusted to 7.0 with additional pH 7.4 phosphate buffer. After removing residual organic solvents in vacuo the aqueous solution was applied to a C18 reverse-phase column.

Elution with H2O and lyophilization ofthe relevant fractions afforded 0.130g of an amorphous solid. This material was repurified by reverse-phase hplcto give the pure product (0.058 g, 34%) as an amorphous solid. ir(KBr) vmax: 3420 (br, OH), 1750 (ss-lactam CO), 1590 (-CO2) cm-1 ; Hnmr (D2O) # : 4.35-2.77 (m, 17H), 3.18 (s, 3H, N-Me), 1.23 (d, J=6.3 Hz, 3H, CHMe) ; uv (H2O) Ajax: 300 (E6344) nm; t (pH 7.4, 36.8 C) 18.5h.

Example 18 Preparation of (5R, 6S)3-[2-(1,4-dimethyl- 1 piperazinium)-methylthio]-6-[1-(R)-hydroxyethyl] 7-oxo-1-azabicyclo-[3.2.0]hept-2-ene-2carboxylate

A. 1-(2-acetylthioethyl)- 1,4-dimethylpiperazi nium bromide

A solution of 2-bromoethyl thiolacetate *(2.20 g, 0.012 mol) and 1,4-dimethylpiperazine (1.95 mL, 0.014 mol) in acetone (4 mL) was stirred at S00Cfor 65 H. Atter cooling to 25 C, the liquid phase was decanted from the gum which was triturated twice in diethyl ether; a hygroscopic yellowish powder, 3.2 g (90%) was obtained ; ir (Nujol) Vmzx : 1685 (C=O of thioester) cm-1 ; Hmr (D2O) # : 2.37, 2.39 (2s, 6H,

*B. Hansen,Acta Chem.Scand. 11,537-40 (1957) B. 1,4- dimethyl-1-(2-@ mercaptoethyl)piperazi- nium bromide hydrochloride

A solution of 1 - (2 - acetylthioethyl) - 1,4dimethylpiperazinium bromide (1.1 g, 3.7 mmol) in 6N hydrochloric acid (4 mL) was heated at80 C under a nitrogen atmosphere for 1 h. The solution was concentrated under reduced pressure to give a white powder, 0.41 g(38%), Hmr (DMSO, d6) # : 2.90 (s,

Anal. Calcd. for C8H20N2SBrCl.H2O : C31.03, H 7.16, N 9.05, S 10.35 ; found C31.62, H 7.46, N 9.19, S 10.19.

C. (5R, 6S) Paranitrobenzyl3-[2-(1,4-dimethyl-1 piperazinium)eth ylthio] - - [1- (R) - hydroxylethyl] - 7 - oxo -1-azabicyclo[3.2.0]hept -2 - ene - 2 - carboxylate diphenylph osphate

To a cold (0 C) solution of (5R,6S) paranitrobenyl 6 [-(R)-hydroxyethyl]-3,7-dioxo1azabicyclo[3.2.0]heptane-2-(R)-carboxylate (0.465 g, 1.33 mmol) in acetonitrile (2 mL) kept under a nitrogen atmosphere was added diisopropylethylamine (0.278 rnL, 1.59 mmol) and diphenyl chlorophosphate (0.33 mL, 1.59 mmol).The reaction mixture was stirred for 30 min and treated with a suspension of 1,4-dimethyl - 1 -(2- mercaptoethyl) piperazinium bromide hydrochloride (0 (0.40 g, 1.37 mmol) in acetonitrile (3 mL)-water (1 mL) mixture and diisopropylethylamine (0.278 mL, 1,59 mmol).

After stirring for 18 hat 5 C, @@ cold water (15 mL) was added to the mixture. The resulting solution was chromatographed over PrepPak-500/C18 (V (Waters Associates) column (2.5 x 7.5 cm) with 25-35% acetonitrile in water as eluting solvents to give a yellowish powder 0.50 g (50%) after lyophylization ; ir ir (KBr)Vmax : 1765 (C=O of ss-lactam), 1690 (C=O of PNB ester), 1585 (phenyl), 1512 (NO2), 875 (NO2)cm-1, Hmr (DOSO, d6) # : 1.16, 1.18 (2d, J=6.1 Hz, 3H, CH3CHOH), 2.44

5.31 (d, J=6 Hz, CH), 5.39 (center of ABq, J= 13 Hz, CH2 of PNB), 6.6-7.4(m, iOH, phenyl of phosphate), 7.71 (d, J=8.8 Hz, 2H, Ho of PNB), 8.26 (d, J=8.8 Hz, Hm of PNB).

D. (5R,6S)3-2-(1,4-dimethyl-1-piperazinium)ethylthio]-6-[1-(R)-hydroxyethyl]-7-oxo-1 - azabicyclo[3.2.0] hept - 2 - ene - 2 - carboxylate

To a solution of(SR,6S)paranitrobenzyl 3- [2 - (1,4dimethyl-1-piperazinium)ethylthio]-6-[1-(R)hydroxyethyl] - 7 - oxo - 1 - azabicyclo[3.2.0]hept - 2 ene - 2 - carboxylate diphenylphosphate (0.47 g, 0.623 mmol) in wettetrahydrofuran (25 mL) was added diethyl ether (25 mL), potassium phosphate monobasic-sodium hydroxide buffer (13 mL, pH 7.22) and 10% palladium on charcoal (0.47 g).The resulting mixture was hydrogenated at 23 C under 40 psi for 1 h. The two layers were separated and the organic layer was extracted with water (2 x 7 mL).The aqueous layers were combined, filtered through a Celite pad, washed with diethylether (2 x15 mL) and chromatographed on PrepPak-500/C18 (Waters Associates} column (2.5 x 9.5 cm) with water as eluting solventto give, 0.097 g (43%) after lyophylization; ir (KBr) vmax: 3000-3700 (OH), 1750 (C=O of ss-lactam), 1585 (carboylate) cm-1, Hmr (D2O) #: 1.24 (d, J=6.4 Hz, 3H, CH3CHOH), 2.33(s, 3H,

4.0-4.5 (m, H-5. CH3CHOH), uv (H2O) Ajax: 296 (#9476), [&alpha;]D 61.1 (CO. 26, H2O), t1/2 = 12.4 h (measured at a concentration of 10-4 M in phosphate buffer pH 7.4 at 36.8 C).

Example 19 Preparation of(SR,6S) - 3 - [2 - (N - methyl thiomorpholiniumoxide] - 6- [1- (A) - hydroxyethyl] - 7-oxo- 1 -azabicyclo(3.2.0) -hept-2-ene-2carboxylate

To a cold (-10 ) solution of (5R,6S) - 3 - [2 - (N methyl-thiomor pholinium) ethylthio]-6-[1-(R)hydroxyethyl] - 7 - oxo - 1 - azabicyclo(3.2.0) - hept - 2 ene -2 -carboxylate (608 mg, 1.65 mmol) in a 1:1 mixture of acetonitrile-water (9 mL) was added m-chloroperbenzoic acid (334.8 mg, 1.65 mmol) in small portion over a 1 hour period. The mixture was then diluted with water (15 mL) and washed with diethyl ether (3 x 15 mL).The aqueous phasewas pumped under vacuum and passed th rough are versed phase silica gel column (H2O)to give a solid which consisted of a mixture of compounds. This mixture was separated by reversed phase HPLC and afforded fraction A 52.4 mg (yield 12%) ; and fraction B 23.6 mg (yield 6%) as diastereomers ofthe title compound; Fraction A: ir (nujol) vmax: 1750(s, ss-lactam C=O) and 1580 cm-1 (s, C=O), Hmr (D2O) # : 4.26-2.91 (20 H, m, H-4, H-5, H-6, H-1', CH2S, CH2S-O, CH3-N+ and CH2N+) and 1.24 ppm (3H, d, J=6.4Hz, CH3); uv (H2O, c 0.06) Ajax: 302 (E10425); T 1/2:12 h (0.065 M, pH 7.4 phosphate buffer, 37 C).

Fraction B : ir (nujol) Vmax : 1750 (s, ss-lactam C=O) and 1585 cm-1 (s, C=O) ; Hmr (D2O) # : 3.86-2.90 (17 H, m, H-4, H-5, H-6, H-i', CH2S, CH2S-O, CH2N+), 3.25 (3H, s, CH3N+) and 1.24 ppm (3H, d,J=6.4 Hz, CH3); uv (H2O, c 0.05) Amax: 2.99 (E6517); T1/2:10.75 h (0.0665 M, pH 7.4 buffer solution, 37 C).

Example 20 Preparation of(5R,6S) - 3 - [2 - (1,4,4 - Trimethyl - 1- piperazinium) ethylthiol - 6 - [iR - hydroxyethyl] - 7oxo-1-azabicyclo(3.2.0)hept-2-ene-2-carboxyalte chloride

A. 1-(2-acetylthioethyl)-1,4,4-trimethylpiperazinium bromideiodide

A suspension of 1 - (2 - acetylthioethyl) - 1,4 dimethylpiperazinium bromide (1.48 g, 5.0 mmol) in isopropyl a Icoho 1(10 m L) was treated with methyliodide (0.373 mL, 6.0 mmol) and heated at 55-60 C for 30 h. The solvents were evaporated under reduced pressure; the residue was triturated in hexane and the solid was filtered, 1.85 g. The solid was dissolved in hotwater (8 mL) and the solution was diluted with acetone until turbidity (70-80 mL).Two successive crystallization gave 1,5 g, mp 220-5 C dec., 68% ofthe title compound ; ir (KBr) Vmax : 1692 cm-1 (C=O) ; Hmr (D2O) ; Hmr (D2O) # : 2.40 (s, 3H, CH3COO), 3.37 (s, N-CH3), 3.39(s, N-CH3), 3.99(s); uv (H2O) Ajax: 226 (#13144). Anal. calcd for cl1H24N2OSBrl: C 30.08, H 5.51, N 6.38;found: C30.48, H 5.53, N 6.86.

B. 1- (2 - mercaptoethyl) - 1,4,4 - trimethylpiperazinium bischloride

A mixture of 1 - (2 -acethylthioethyl)- 1,4,4trim ethylpiperazinium bromide (1.84 g, 4.19 mmol) and 6N hydrochloric acid (15 mL) was heated at 57 C undera nitrogen atmospherefor2.5h.Thesolution was concentrated under reduce pressure to dryness.

The solid was suspended in water (10 mL) and the well-stirred suspension was treated with permutit S-1 Cl - until a solution was obtained. The solution was poured on a column (1.2 x 60 cm) of permutit S-1 Cl-.The column was eluted with water (1.5 mL/min).

The appropriate fractions were combined and lyophilized to give a white powder, 0.93 g, mp 190-191 C, 85% ; ir (nujol) Vmax : 2460 (SH) ; Hmr (D2O) O: 3.4 (s, N-CH3), 3.45 (s, N-CH3), 4.07 (s). Anal. calcd Tor C9H22N2SCl2 0.75 H2O: C 39.34, H 8.62, N 10.20, S 11.67 ; found : C 39.48, H 8.39, N 10.55, S 11.15.

C. (5R,6S) paranitrobenzyl 3- [2 - (1,4,4 - trimethyl -1 -piperazinium)ethylthio]- 6- (1R-hydroxyethyl]- 7- oxo - 1- azabicyclo(3.2.0)hept - 2 - ene - 2 - carboxylate bischloride

To a cold @(5 C) solution of (5R, 6S) paranitrobenzyl 6 -[1R-hydroxyethyl]- 3,7- dioxo -7-azabicyclo-l- azabicylco (3.2.0) heptane-2R-carboxylate (0.94 g, 2.7 mmol) in acetonitrile (3 mL) kept under a nitrogen atmosphere was added diisopropylethylamine (0.557 mL, 3.2 mmol) and diphenyl chlorophosphate (0.663 mL, 3.2 mmol).The reaction mixture was stirred at 5 C for 30 min and treated with diisopropylethyla mine (0.599 mL, 3.44 mmol) and an aqueous solution (4 mL) of 1 - (2 - mercaptoethyl) - 1,4,4 -trimethyl piperazinium bischloride (0.90 g, 3.44 mmol). After 1.25 h, diisopropylethylamine (0.1 mL, 0.57 mmol) was stirred and the stirring was continued for 2 h. A part ofthe acetonitrile was eliminated under reduced pressure and the resulting red mixture was chroma- tog graphed on 1PrepPak-500/C18 (Water Associates) column with 25-75% acetonitrile in water as eluting solventto give a yellowish powder (1.4 g) after lyophylization. The powder was solubilized in water and the solution was passed on a column (1.2 x 58 cm) of permutitS-1 Cl- using water an eluting solvent.Lyophlization ofthe appropriate fractions gave 1.17 g of a powderthatwas repurified on a column of PrnpPak-500/cl5. Lyophylization ofthe appropriate fractions gave a yellowish powder, 0.80 g (53%); ir (KBr) vmax: 3400 (br, OH), 1770 (C=O ofthe ss-lactam), 1690 (C=O of PNB ester), 1605 (aromatic), 1515 (NO2), 1345 (NO20cm-1 ; Hmr (D2O) # : 1.26 (d, J=6.3 Hz, 3H, CH3CHOH), 3.39(s, NCH3), 4.00 (s), 5.37 (br, s,CH2 of PNB), 7.60 (d, J=8.6 Hz, 2H, Ho of PNB), 8.20 (d, J=8.7 Hz, 2H, Hm of PNB); uv (H2O) Ajax: 276 (#12094), 306 (#10752).Anal. calcd. for C25H36N4O6SCL2 3H2O: C 46.51, H 6.56, N 8.68, S 4.97, Cl 1 10.98; found: C 46.31, H 6.18, N 8.57, S 5.36, Cl 11.37.

D. (5R,6S)-3-[2-(1,4,4-trimethyl1-piperazinium) ethylthio]-6-[1R-hydroxyethyl]-7-oxo-1azabicyclo(3.2.0)hept-2-ene-2-carboxylate chloride

A mixture of (5R, 6S) paranitrobenzyl-3-[2-(1,4,4 trimethyl - 1 - piperazinium) ethylthio] -6 - [1 A- hydroxyethyl] - 7 - oxo - 1 - azabicyclo(3.2.0)hept - 2 ene -2- carboxylate bischloride (0.40 g, 0.68 mmol), phosphate buffer (30 mL, 0.05M, pH 7.0), tetrahydrofuran (10 mL), ether (30 mL) and 10% palladium on charcoal (0.40 g) was hydrogenated at 230C under 35 psi for 1 h. The two phases were separated. The organic phase was extracted with water (10 mL). The aqueous phases were filtered on a Celite pad, washed with ether (10 mL), concentrated under vacuum to 10 mL and chromatographed on PrePak-500/C18column (2.2 > c 11 cm)with water as eluting solventto give 70 mg (25%) after lyophylization; ir (KBr) vmax: 3400 (br, OH), 1755 (C=O of the , - lactam), 1585 (carboxylate) cm-1 ; Hmr (d2O) # : 1.24 (3H, d, J=6.3 Hz, CH3CHOH), 3.36 (s, NCH3), 3.98 (s); uv (H2O) Ajax: 296 (#7987 ) ; [&alpha;]D 35.9 (c, 0.30, H2O), T112 = 9.8 9.8 h (measured at a concentration of 10-4 M in phosphate buffer pH 7.4 at 36.8"C).

Claims (17)

1. Aprocessforthepreparation ofacarbapenem derivative of the formula

wherein R8 is hydrogen and R' is selected from the group consisting of hydrogen; substituted and unsubstituted: alkyl, alkenyl and alkynyl, having from 1-10 carbon atoms; cycloalkyl and cycloalkylalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in the alkyl moieties; phenyl; aralkyl, aralkenyl and aralkynyl wherein the aryl moiety is phenyl and the aliphatic portion has 1-6 carbon atoms; heteroaryl, heteroaralkyl, heterocyclyl and heterocyclylalkyl wherein the hetero atom or atoms in the above-named heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen orsulfuratoms and the alkyl moieties associated with said heterocyclic moieties have 1-6 carbon atoms; wherein the substituent orsubstituents relative to the above-named radicals are selected from the group consisting of C1 -C6 alkyl optionally substituted by amino, halo, hydroxy or carboxyl halo

wherein relative to the above-named substituents, the groups R3 and R4 are independently selected from hydrogen; alkyl, alkenyl and alkynyl, having from 1-10 carbon atoms; cycloalkyl, cycloalkylalkyl and alkylcycloalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in the alkyl moieties; phenyl; aralkyl, aralkenyl and aralkynyl wherein the aryl moiety is phenyl and the aliphatic portion has 1-6 carbon atoms; and heteroaryl, heteroaralkyl, heterocyclyl and heterocyclylalkyl wherein the hetero atom or atoms in the abovenamed heterocyclic moieties are selected from the group consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkyl moieties associated with said heterocyclic moieties have 1-6 carbon atoms, or R3 and Retaken together with the nitrogen to which at least one is attached may form a 5- or 6- membered nitrogen-containing heterocyclic ring; R9 is as defined for R3 except that it may not be hydrogen; or wherein R1 and R8 taken together represent C2-C10 alkylidene or C2-C,0 alkylidene substituted by hydroxy; A is cyclopentylene, cyclohexylene or C2-C6 alkylene optionally substituted by one or more C1-C4 alkyl groups;R2 is hydrogen, an anionic charge or a readily removable carboxyl protecting group, providing that when R2 is hydrogen ora protecting group, there is also present a counter anion; and R14 is quaternized nitrogen-containing aromatic or nonaromatic heterocycle attached to Athrough a ring nitrogen, thereby forming a quaternary ammonium group, or a pharmaceutically acceptable salt, thereof, which process comprises reacting an intermediate of the formula

wherein R1 and R8 are as defined above, R2 is a readily removable carboxy protecting group and L is a leaving group,with athiol compound oftheformula HS-A-R14 Xe VII wherein Aand R'4are as defined above and Xe is a counter anion, in an inertsolventand in the presence of base, to produce a carbapenem product of the formula

wherein R7, R8, R2, A, R14 and Xe are as defined above and, if desired, removing the carboxyl protecting group R2 to give the corresponding de-blocked compound offormula I, ora pharmaceutically acceptablesaltthereof.

2. The process according to Claim 1 wherein the base is a non-nucleophilictertiary amine or a tri(C1-C4)alkylamine.

3. The process according to Claim 2 wherein the base isa non-nucleophilictertiaryamine.

4. The process according to Claim 1.2or3 wherein the reaction is carried out at a temperature of -iSCupto room temperature.

5. The process according to Claim 4wherein the reaction is carried out at a temperature in the range of from about -15 Cto +15 C.

6. The process according to Claim 1,2,3,4Or5 wherein the inert solvent is selected from the group consisting of acetonitrile, a mixture of acetonitrile, dimethylformamide, tetrahydrofuran, a mixture of tetrahydrofuran and water, a mixture of acetonitrile and water and acetone.

7. Aprocessforthe preparation of a quaternary aminethiol compound of the formula HS-A-R14 wherein A is cyclopentylene, cyclohexylene or

in which B10, R11, B12 and R13 are each independently hydrogen or C1-C4alkyl, Xe is a counter anion and R14 represents a substituted or unsubstitute mono, bi- or polycyclic aromatic or non-aromatic heterocyclic radical containing at least one nitrogen in the ring and attachedtoAthrough a ring nitrogen, thereby forming a quaternary ammonium group, which process comprises reacting a sulfide ofthe formula

wherein R10, R, R12 and R13 are each independently hydrogen or C1-C4 alkyl with a strong acid and either (a)aheteroaromaticamineoftheformula

represents a substituted or unsubstituted mono-, bior polycyclic aromatic heterocyclic radical containing at least one nitrogen in the ring capable of being quaternized and bonded to a carbon atom ofsubstituentA or (b) a heterocyclic amine ofthe formula

represents a substituted or unsubstituted mono-, bior polycyclic non-aromatic heterocyclic radical containing at least one nitrogen in the ring capable of being quaternized bysubstituent R16 and bonded to a carbon atom of substituent A and B16 represents either (a) an optionally substituted aliphatic, cyc- loaliphatic, cycloaliphatic-aliphatic, aryl, araliphatic, heteroaryl, heteroaraliphatic, heterocyclyl or heterocyclyl-aliphatic radical or (b) a divalent phenylene or C1-C4alkylene group joined to the

ring so as to form a bridged polycyclicgroup.

8. The process according to Claim 7 wherein the reaction is carried out at a temperature in the range of from about -200Cto about 100 C

9. The process according to Claim7 or8 wherein the strong acid is hydrochloric, hydrobromic, methanesulfonic, p-toluenesulfonic ortrifluoromethanesulfonic.

10. The process according to Claim 7,8 or9 wherein the reaction is carried out in the presence of a non-polar organicsolvent, preferably methylene chloride, benzene, xylene ortoluene.

11. The process according to Claim 7,8,9 or 10 wherein when the amine and sulfide reagents are liquids or when the amine reagent is a solid, the sulfide reagent is liquid and the solid amine is soluble in the liquid reagent, the reaction is carried out without additional solvent.

12. A quaternary aminethiol compound of the formula HS-A-R14 Xe VII wherein A is cyclopentylene, cyclohexylene or

in which R10, 1 R", R12 and R'3 are each independently hydrogen or cl-C4 alkyl, Xe is a counter anion and R14 represents a substituted or unsubstituted mono, bior polycyclic aromatic or non-aromatic heterocyclic radical containing at least one nitrogen in the ring and attached to Athrough a ring nitrogen, thereby forming a quaternary ammonium group.

13. A process according to claim 1, substantially as described in any of the foregoing Examples.

14. A process according to claim 7, substantially as described in any of the foregoing Examples.

15. A ca rbapenem derivative prepared by a pro- cess according to any of claims 1 to 6 or claim 13.

16. A quaternary ammonium thiol compound prepared by a process according to any of ciaims 7 to ii or claim 14.

17. A pharmaceutical composition comprising a carbapenem derivative as claimed in claim 15 and a pharmaceuticall@@ accentable carrier or diliient