CA1197252A - Derivatives of cis, endo-2-azabicyclo-[3.3.0]- octane-3-carboxylic acid a process for their preparation, agents containing these compounds and their use - Google Patents

Abstract

Abstract of the Disclosure A process is provided for the production of compounds of formula wherein (II) R1 denotes hydrogen, allyl, vinyl or a side-chain of a naturally occurring .alpha.-aminoacid R1-CH(NH2)-COOH, which may be protected, R2 denotes hydrogen, (C1-C6)-alkyl, (C2-C6)-alkenyl or aryl-(C1-C4)-alkyl, Y denotes hydrogen or hydroxyl and Z denotes hydrogen, and X denotes (C1-C6)-alkyl, (C2-C6)-alkenyl or (C5-C9)-cycloalkyl, or (C6-C12)-aryl, which can be mono-, di- or tri-substituted by (C1-C4)-alkyl, (C1-C4)-alkoxy, hydroxyl, halogen, nitro, amino, (C1-C4)-alkylamino, di-(C1-C4)-alkylamino or methyl-enedioxy, or denotes indol-3-yl.
Also provided are products of the formula IV

Description

%~

~OE 82/F 14B J

This application is a divisional of Canadian Patent Application serial number 414,858 filed November 4, 1982.
The ;nvent;on relates to der;vatives of cis,endo-azabicyclo-C3~340~-octanecarboxylic ac;d of the formula I
~ ~1 *
T~ ~ * I I 1 2 HOOC C~2 CH~
in ~hich the hydrogen atoms on the bridge-head carbon atoms 1 and 5 are in the cis-conf;guration relative to one another and the carboxyl group on carbon atom 3 is or-ienta-ted ;n the endo-pos;t;on relative to the bicyclic ring system, and ;n wh;ch R1 denotes hydrogen, allyl, vinyl or a side-chain of a naturally occurr-ing ~~aminoacid R1-CHtNHz)-COOH, ~hich may be protected, R~ denotes hydrogen, tC1-C6)-alkyl, tC2-C6)-alkenyl or aryl~{C1-C4)-alkyl, Y denotes hydrogen or hydroxyl and Z denotes hydrogen, or Y and Z together denote oxygen, and X denotes ~C1-C6~-alkyl, (Cz-C6)-alkenyl or ~C5-C9)-cycloalkyl, or (C6-C12)-aryl, pre~erably phenyl, ~hich can be mono~-, di~ or tri-substituted by (C~-C4)-alkyl, t~ -C~)~alkoxy, hydroxyl, halogen, nitro, ~7~
" ~,~

amino, tC1~C4)-alkylam;no~ di-(C1-C4) alkylamino or me~hylenedioxy~ or denotes ;ndol-3-ylO
and phys;olog;cally acceptable salts thereof.
Compounds of the formula I ;n ~h;ch R1 denotes methyl, the side-chain of lys;ne, ~hich may be acylated, or the O-alkylated side-chain of tyrosine, R2 denotes hydrogen, methyl, ethyl or benzyl, X denotes pheny~ or phenyl which is mono- or di~
subst;tuted by fluor;ne and/or chlor;ne, Y denotes hydrogen or hydroxyl and Z denotes hydrogen, or Y and Z together denote oxygen, are preferred.
If R1 represents a s;de-cha;n of a protected natur-ally occurring ~-am;noacid, such as, for example, proeected Ser, Thr, Asp, Asn, Glu, Glny Arg, Lys, Hyl, Cys, Orn, C1t, Tyr, ~rp, His or Hyp, the groups customary ;n pept~de chemistry are preferred as protective groups tcf. Houben-Weyl, ~olume XV/1 and ~V~2)). In the case where R1 denotes 20 the protected lys;ne s;de-cha;n, the known am~no-protect;ve 0roups are preferred, éspecially ~C1-C6) alkahoyl. Preferred O-protective groups for tyrosine are methyl or ethyl, Possible salts are, in part~cular, the hydro~
chlorides~ maleates and tartrates, and the alkali metal, Ca, ~lg and Zn salts.
The chirality centers on the carbon atoms labeled with a star ~*) in the chain and on carbon atom 3 of the bicyclic ring system can have ei~her the R-conf;guration or the S-configuration. However, compounds ;n ~hich these centers are in the S-conf;guration are preferred~ If

2~2 -NH-*CH~l-CO~ represents Cys, howeYer, the R-configuration of this center is preferred S The ~nvent1on furthermore rel~tes to a proc~s~ for the preparat;on of the compounds of ~he formul3 I, which comprises react;ng a compound of the formula II ;n which R2 has the abovement;oned mean;ngs, w;th the except;on of hydrogen, with a compound of the formula IIIa or IIIb, in uhich W denotes 3 carboxyl-esterify;n~ group, such as (C1-C6)~alkyl or (C7-C8)-aralkyl, preferably tertu-butyl or benzyl, by the kno~n am;de format;on methods of peptide chem;stry, and then liberat;ng the compounds of type I by hydrogenation or treatment ~ith an acid or/and base.
Z R~
l' l X - C - CH2 - CH -- NH - CH - C02H tII) Y C2R' }IN r ~'~2 C ~ ~~J t I I I a ) H~
wo2c ~iJ
(IIIb) Compounds of the formula II ;n wh;ch X ;s phenyl, Y ;s H, Z ;s H and R2 is CH3 or CzH5 are kno~n ~for example from European Patent 0,û37,2~1), and are accessible 7~5~:
_ 5 ~
ln var~ous ways~ The benzyl ester ~R2 ~ benzy~) can be prepared analogously.
It h~s furthermore been f~und th~t the Mann~ch react1on of acetophenones of the formula IVa, ~n uh~ch X
represgnts aryl which ~s optionally substituted as deso crib*d above, ~ith glyoxyl~c acid esters ~nd ~-aminoacid esters leads to compounds of the formula ~I ~n ~hich Y ~nd Z together denote oxygen ~formu~a IV). In tormula IV, ~' denotes a rad~caL which can be s~it of under basic or acidic conditions or by hydrcgenolysis, preferably benzyl or tert.-~utyl, X represents aryl ~hich ;s optionally subst~tuted as des-cribed abGve and R1 and R2 have the abovementioned mean-ings. HoweverO ;n the case of the benzyL ester ~W' =
benzyl~ R2 may not be benzyl. Hydrogenolysis of these compounds ~ith Pd gives compounds of the formula I~ in ~hich Y and Z are hydrogen.

X-CO~CH3 ~ CHO ~12N-CH-CO~W' fO~R

C 2 ~ X-CO~CH2-CH-N}I-C~J-CO ~;' IVA IV
Corpounds of the formula II ;n wh;ch Y and Z
~ogether denote oxygen can also be obtained ;n h;gh y;elds by M;chael add;t;on of correspond;ng keto-acryl;c ac;d esters w;th ~-aminoacid esters. Ester cleavage leads to the same products as the Mann;ch reaction.

~,~., .

~L972~2 ' o ~1 Il ~ ' I , .
X-C-C~l-CH-CO2R ~ N~12 ~ CH-C0~ V
When L-alanine esters are used, the diastereo~ers ~ith the preferred S,S ~onf;~urat;on are predom;nantLy formed, and can be ;solated by crysta~lization or by S chromatograph;c separat;on of the esters of II on sil;ca gel.
I~ has furthermore been ~ound that cis~endo-2~a-bicyclo~3.3.0]octane-3-carboxylic acid esters of th~
formulae III a and b are accessible from enamines of cyclopentanone of the formula VI, in ~Ihlch X1 represents dialkylamino ~ith 2 to 10 carbon atoms or a radical of the formula YII~ in wh;ch m and o denote integers from 1 to 3, ~m ~ o) ~ 3 and A denotes CHz, NH, 0 or S~

x1 " ~YI

/c1'12--.7m ~N \~ ~VIIj /CH~ 70 and N-acy1ated ~ha109eno~c4~amino~carboxy1ic acid esters of the formula VIII, in which x2 represents a 9roup whlch can escape nuc1eofu9a11y, preferab1y chlorine or bromine, y1 represents alkanoyl with 1 to 5 carbon atoms, aroyl with 7 to 9 carbon atoms or other protect~ve groups which are customary in pept;de chemistry and can be split off under ac;d cond;-tions~ and R2 represents alkyl with 1 to 5 carbon atoms or aralkyl ~îth 7 to 9 carbon atoms x2 .
C~32 (\IIII~
CH

Y 1 -l~N COOR
or with acrylic ac1d esters of the formula IX~ in ~h;ch y1 and R2 have the above meanings, ~ COt)R

C~1:2 = C tIX) \ NH~

by react;ng these start;ng mater;als to g;ve compounds of ~he formu(a X, in which R~ and y1 have the above meanings~

U{, C~ C~l tX) NH_~1 . cycliz;ng these compounds w;th the aid of strong acids, w;th acylam;de and ester cleavage, to g;ve compounds of the formula XI a or b 72~

~J~M1 COOH
a tXI) ~N J~
OOH
H b convertin0 these ;nto compounds of the formula IIla or b, in uh;ch W represents hydrogen, by catalytiG hydrogenation in the presence of transition metal catalysts or by reduc-tion ~ith borane~amine complexes or complex borohydrides;n lo~er alcohoLs, and opt;onally esterifyi~g the products to give compounds of the formula III a or b in ~h;ch ~
represents alkyl with 1 to o carbon atoms or aralkyl ~th 7 to 8 carbon atoms.
The bicyclic aminoacids of the formulae IIIa and b have the c;s,endo-configuration, i.e. the -CO~W group faces the cyclopentane ring. All thc other 2-azabicyclo-~3.3.0~-octane-3-carboxylic acid derivatives mentioned in the present invention are also in the c1s,endo-conf;gura-t;on.
Examples of preferred enamirles are pyrrol~dino-cyclopentene and morpholinocyclopentene~ Cyclization of the alkylation products of the formula X is preferably carried out with aqueous hydrochloric acid~ The compounds of the formula III tin which W is H) can be esterified by the methods customary for aminoacids (cf. for example, Houben-Weyl, Methoden der organischen Chemie ~Methods of Organic Chemistry), Volwme VIII (195~)), for example with 5~2 th;onyl chloride/benzyl alcohol or isobutylene/sulfur;c acîd~ They give~ after appropriate ~orking up, compounds of the formula III ;n the form of the free base or of a salt.
The new compounds of the formula I have a lony lasting, ;ntense hypotens;ve act;on. They are po~erful ;nhib;tors of the ang;otensin-convert;ng enzyme (ACE in~
h;b;tors) and can be used for controll;ng h;gh blood pres-sure of various or;g;ns. They can also be comb;ned w;th other hypotensive, vasodilat;ng or d;uret;c compounds.
Typ;cal representat;ves of these classes of active com-pounds are described in, for example~ Erhardt-Ruschig, Arzneimittel tMed;caments), 2nd edit;on, Weinheim, 1972.
They can be adm;nistered intravenously, subcutaneously or perorally~ me dosage for oral administration is 1 - 100, ~ ~ly 1 - 50, especially 1 - 30 ~ per lndivid~ se ~or an adult of normal body weight. In severe cases, it can also be increased, slnce no tox;c propert;es have as yet been observed. It is also poss;ble to reduce tho dose, uhich is appropr;ate, above all, 1f d;uretic agents are admin~s-2n tered at the same time~
The compounds according to the invention can beadministered orally or parenteraLly ;n an appropriate pharmaceutical ~ormulation. For an oral use form, the active compounds are mixed with the addltives customary for th;s form, such as excipients, stabili~ers or inert diluents, and the mixture is converted to suitable adminis-tration forms, such as tablets, dragees~ push-fit cap-sules, aqueous alcoholic or oily suspensions or aqueous alcoholic or o;ly solutions, by customary methods.

s~
- 10 ~
.. ~ .
Examples of ;nert carriers which can be used are gum arab;c, magnesium stearate, potass;um phosphate~ lactose, glucose and starch, espec;ally ma;ze starch. The forrnula-tion may be prepared in the form of e~ther dry or moisS
granulesn Examples of possible oily exc;pients or sol-vents are vegetable and animal oils, such as sunflower oil or cod-l;ver oil~
For subcutaneous or intravenous admin;stration, the act;ve compounds or phys;ologically acceptable salts thereof are d;ssolved, suspended or emuls;~;ed, if des;red ~ith the substances customary for this purpose, such as solub;l;z;ng agents, emulsif;ers or other aux;l;aries.
Examples of poss;ble solvents for the new active compounds and the correspond;ng physiologically acceptable salts are:
water, phys;ological sod;um chlor;de solut;ons or alco-ho~s, for example ethanol~ propanediol or glycerol, and in add;t;on also sugar solut;ons, such as ~lucose or mannitol solut;ons~ or a m;xture of the various solvents ment1oned.
The except;onally powerful activ;ty of the com-pounds accord;ng to the formula I - even when adm;n;stered orally - ~s demonstrated by the followin~ pharmacolog;cal data~
1. Intravenous adm;n;strat;on to anesthet;zed rats, 50X
inh;bition of the pressor react;on ;nduced by 310 ng of ang;otens;n I, 30 m;nutes after adm;n;strat;on of the dose ... EDSo X Y Z R1 R2 ED50 ~g/k~) C6H5 H 7I CH3 C2H5 8.3 C6H5 ~ H CH3 H 2.7 2. Intraduodenal adm;n;s~ra~ion to anesthe~;~ed rats S X Y Z R1 ~2ED~ t~g/kg~
C6H5 H H ~H3 C2H5 50 C6H5 H H CH3 ~1 600 C6H5 ~ CH3 CH3 350 C6H5 ~ CH3 C2H5 280 C6Hs - CH3 C7H7 250 C6H5 H OH CH3 C2H5380 l p~ C6H4 H H CH3 C2Hs 55 p-Cl-C6H4 ~ O CH3 H 780

3. On.oral adm;n;strat;on to consc;ous rats, a dosage of 1 m0tkg of, for example, the compound of the formula I in wh~ch X ;s phenyl, Y and ~ are each H, R1 is CH3 and R2 7S ethyl exhibits 90% inhibition, lastin~ over o hours, of the pressor react;on trlggered ofF by ;ntravenous adminis-tration oF ang;otensin I.
the Examples wh;ch Follow are ;ntended to illus-trate the procedures accord;ng to the invent;on, w;thout restr;ct;ng the ;nvention to the substances ment;oned here as representatives.

~72~i2 Example I:
N~ S~Carbethoxy-3-phenyt-propyl) S~alanyt~2-cis,endo-azab;cyclo~3.3.0~-octane-3-S~carboxylic ac;d ~1) Methyl 2-acetylamino-3-~2-oxo-cyclopentyl)-propionate:
S 269 9 of methyl 3-chloro-2-acetylamino-prop;onate and 257 9 of cyclopentenopyrroLid;ne ;n 1.5 liters of dimethylformamide ~ere kept at room temperature for 24 hours~ The mixture was concentrated ;n vacuo, the res;due was taken up ;n a little water and the aqueous mixture ~as adjusted to pH 2 with concentrated hydrochlor;~ acid and extracted tw;ce with 4 liter portions of ethyl ace~ate.
On concentration of the organic phase, a light yellow oil remained.
Yield: 290 9. ~
~5 NMR: Z~02 ~s,3H); 3.74 ~s 3H); 4.4-4~8 (m,1H) ~CDCl3) Analysis: C H N
calculated 58.1 7.5~ 6.16 found58.5 7.2 6.5 ~2) c;s,endo-2~Azab;cycLo-C3.3.0J-octane-3-carboxylic acid hydrochloride 270 g of the acetylamino derivative prepared under ~1) were boiled under reFlux ;n 1.5 liters of 2 N hydro-chlor;c ac;d for 45 m;nutes. The mixture was concentrated ~n vacuo, the residue wa~ taken up ;n glacial acetic acid, 5 g of Pt~C ~10X of Pt) were added and hydro~enation was carr;ed out under S bar. AFter filtration, the mixture was concentrated and the res;due was crystall;zed from chloroform/diisopropyl ether.
Melting point: 205 - 20~C, ~7~2 . . .
Yield: 150 g - (3~ senæyl c;s,endo-2-a~abicyclo-C3.3~0J-octane-3-carboxylate hydrochlor;de 40 g of the carboxylic acid prepared under ~2) ~ere added to an ice-coLd mixture of 390 9 of benzyl alco hol and 65 9 of thionyl chloride and the m;xture ~as left to stand at room temperature for 24 hours~ After concen-tration in vacuo, 47 g of the benzyl ester ~ere cry~al-lized from chloroform/isopropanol.
10 Melt;ng point~ 175C ~hydrochlor;de) ~4) Benzyl N-(2-S-carbethoxy-3-phenyl-propyl)-S-alanyl-cis,endo-2-azabicyclo-C3~3.0~-octane-3-S-carboxylate 14 g of the benzyl ester prepared according to S3) were reacted w;th 6.7 g of HOBt~ 13~8 g of N-~1-S-carb-ethoxy-3-phenyl-propyl)-S-alan;ne and 10~2 9 of d;cyclo-hexyLcarbodiirnide ;n 200 ml of d;methylformam;de. After the m;xture had been st;rred for 3 hours at room tempera-ture~ the diyclohexylurea wh;ch had prec;pitated was fil-tered off w;th suct;on, the f;ltrate was concentratedr the res;due was taken up in 1 l;ter of ethyl acetate and the mixture was extracted by shaking w;th 3 x 500 ml of 5 per cent strength NaHC03 solut;on~ The organic phase was concentrated and thc rcs;due was chromatographed ovar a column of 1 kg of silica gel using ethyl acetate/petroleum 2S ether ;n the rat~o 2 : 1. The ;somer eluted f;rst was the S,S,S-compound, and concentrat;on of a later eluate gave the S~S,R~compound.
In each case 8.0 g of pr~duct were obtaîned as an oi l..

7~

NMR of the S,S,S~compound: character;st;c signa~s: 1.20 (d,3H~, 1.27 (t,2H), 4.17 tq,3H)O 5.13 ~s~2H), 7.~8 ~s,SH
and 7.32 (s,5H) ~CDCl3) Analysis C 7I N
C30H38N2o5 calculated 71~1 7.56 5.53 found 70.8 7.8 5.7 t5~ N~ S-Carbethoxy-3~phenyl-propyl)-S-alanyl-cis,endo-2-azabicyclo-t3.3.0]~octane-3-S-carboxylic acid ~ .0 9 of the L,L,L-ben~yl ester from (4) ~ere d;s-1Q solved in 100 ml of ethanol and ~ere deben~ylated hydro~
~enolyt;cally under normal pressure, with addition of 0.5 g of 10X Pd/C. This reaction could aiso have been carr;ed out under pressure, together ~;th a shortening of the reaction time. After the calculated amount of hydro-gen had been taken up, the catalyst was filtered off andthe residue ~as concentrated in vacuo. The zwitter ;on crystall;zed from ether, ;n almost quantitative yieldn Melting po;nt- 110 - 112C ~decomposit;on) A llydrochlor;de td~composit;on from 120C) can be obta1ned by addition of an equivalent amount of hydro-chloric ac1d~ or a z;nc complex salts which is particularly stable to heat tdecomposition above 160C) can be obtained by add1t;on of aqueous z1nc saltsto a concentrated methano~
lic solution of the t;tle compound~
Analys1s ~ H N
G23H32N205 calculated 66.3 7.7 6.73 found o6~1 7.8 6.6 The NMR and mass spectra obta;ned are in agreement with the g;ven structure.

7~

~ 15 -G~Jp = ~ 15o6 (c ~ 1~ methano~).
Example II
(1~ tert.-Bu~yl c;s,endo-2-azabicyclo-~3.3.0~-octane-3-carboxylate 25 9 of azabicyclo-C3A3.0~-octane-carboxylic acid hydrochloride from Example I (2) were reacted uith 250 ~
of isobutylene and 25 ml of concentrated sulfuric acid In 250 ml of d;oxane. After 14 hours at room temperature, the m;xture was rendered alkaline with sodium hydrox~de solution and concentrated in vacuo, 1no ml of uater were added and the ester was extracted with ether. Evaporation o~ the ether gave 15 9 o~ a colorless o;l.
Analysis C H N
c12HZ1N0Z calculated 68.2 10.2 6.63 found 67.9 10.1 6.3 ~2) N~ S-Carbobenzyloxy-3-oxo~3-phenyl-propyl)-S-alanine tert~-butyl ester 1Z~0 9 of acetophenone, 17 ~ of benzyl glyoxylate and 31.7 9 of alanine tert.-butyl ester toluenesulfonate ~ere heated to 45 - 50C in 200 ml of glacial acetic acid for 24 to 48 hours. The reaction was monltored by th1n layer chromatography and was interrupted at the optîmum reaction po;nt. The m~xture was concentrated thoroughly ;n vacuo, the res;due was rendered basic w;th aqueous Z5 bicarbonate solut;on and the mixture was extracted with ethyl acetate. The organ;c phase was concentrated as sub-stantially as poss;ble and the S,S~;somer ~as crystallized from cyclohexane/petroleum ether. The ~,S-compound rema;ned substant;ally in solution. To obta;n seed crys-~97~i;2 ta~s~ chromatography of the crude ~ixture on silica gel ~n a 2 : 1 cyclohexane : ethyl acetate system to ~hlch 0~1X
of triethylam;ne had been added was advisable. The S,S-compound ~as eluted as the second of the two d;astereomers and was obta;ned in the larger amount. 9 ~ were obtained.
Analysis C H N
C~H2gN05 calculated 70.1 7.1 3.4 found 70.0 6.~ 3.5 (3) N~ SwCarbobenzyloxy~3-oxo-3-phenyl-propyl) S-alan;ne tr;fluoroacetate 8 9 of the Mannich condensation product from (2) were dissolved in 25 ml of anhydrous trifluoroacet;c acid and the solution was left at room temperature for one hour.
The solution was concentrated ;n vacuo, di;sopropyl ether ~as added and the product was prec;pitated w1th petroleum ether. 7.2 g of an amorphous substance were obtained.
Analysis C H N
C22H2ZNo7F3 calculated 56.3 4.7 3.0 found 56.0 4.8 3.1 Molecular weight: 469

(4) ~ert.-8utyl N-t1-S-carbobenzyloxy-3-oxo-3 phenyl~
propyl)-S-alanyl-2-cis,endo-azabicyclo-C3.3~0~-octane-3~
carboxylate 35.5 g of the N-substituted alanine from t3) were reacted with 21.1 ~ of the t~rt~-butyl azabicyclooctane-carboxylate from Example II (1) analogously to Example I
t4). Chromatography over silica gel gave 20.3 g of the title compound~

~r~

Analys;s C H N
t3~H4~N20~ calculated 70~04 7.35 5~10 found ~9.6 7D4 5.3 ~5~ N~ S-Carbobenzyloxy-3-oxo-3~phenyl-propyl)~S-alanyl-2-c;s~endo~azabicyclo-C3.3O0~-octane-3-carboxyl;c acid 20 g of the tert~-butyl ester from ~4) were d;s-solved in 130 ml of trifluoroacetic acid and the solut;on was left to stand at room temperature for one hour. The solution was concentrated in vacuo, the res;n wh;ch remained was taken up in ~thyl acetate and the mixture ~as neutral;zed ~ith aqueous bicarbonate. 14 ~ of the title compound were obta;ned from the ethyl acetate phase~
Analys;s C H N
C2gH3ZN2o6 calculated 68.27 6.55 5.69 found 68.1 6.4 5~7 ~6) N~ S-Carboxy-3-R,S-hydroxy-3-phenyl-propyl)-S-alanyl-c;s,endo-2-azab;cyclo-C3.3~0~-octane-3-carboxy-l;c acid 1 9 of N ~1-S-carbobenzyloxy-3-oxo-3-phenyl-propyl)-S-alanyl-c1s,endo-Z-azab;cyclo-C3.3.0~-octane-3-carboxylic ac;d were dissolved in 50 ml of ethanol, 150 mg of Pd/BaS04 were added and hydrogenation was carr;ed out under normal pressure. After the calculated amount of hydrogen had becn taken up, the m;xture was f~ltered, the 25 filtrate was concentrated and the residue was chromato-graphed over sllica gel ;n the solvent CHCl3/CH3OH/CH3COOH
50 : 20 : 5.
Y;eld: 0.6 g ~72~

- ~8 -(7~ N~ S7Carbobenzyloxy-3-R~S-hydroxy-3-phenyl-propyl)~
S-alanyl-c;s,endo-2-a~abicyclo-~3~3~0J--octane-3-carboxyl;c acid 1 9 oF N ~1 S-carboben yloxy 3-oxo-3-phenyl-propyl)-S-alanyl-2~c;s,endo-azab;cyclo~3~3.0~-octane-3-carboxylic acid were d;ssolved in 50 ml of a m;xture of acetonitr;le and water and were reduced ~ith 150 mg of NaBH4. After 12 hours, the m;xture ~as concentrated to dryness, the residue ~as rendered neutral with dilute hydrochloric acid and the title compound was extracted Hith ethyl acetate. To remove bor;c ac;d and other impuri-t;es, the product was chromatographed over silica gel ;n the solvent CHCl3/CH30H/CH3COOH 50:10:5.
Analysis C H N
C2gH34N206 calculated 67.99 6.93 5~66 found 67.7 6.6 5.3 Example III
General method: Hydrolysis of esters to prepare compounds of the ~ormula I in which R2 is U.
10 g of the correspondin~ ethyl or benzyL ester of the formula X were d1ssolved ;n 200 ml o~ dimethoxyethanen One drop of a dilute ~ndicator solution, for example bromo-thymol blue, was added, and an equivalent amount of 4N KOH
Saqueous) was added in the course of S minutes, ~h~le stirring v;gorously, so that at the end of the reaction the indicator indicated a pH value of 9 - 10. The mixture ~as then adjusted to pH 4 with hydrochloric acid and con-centrated to dryness in vacuo, the residue was taken up in 250 ml of ethyl acetate and the mixture was filtered. On concentrat;on of the ethyl acetate, the d~carboxyllc ac;ds precipitated as solid, crystalline or amorphous compounds.
The yields were between 8D and 95%.
Example III a

5 N~ S~Carboxy-3-phenyl-propyl)~S-alanyl-c;s,endo-2-aza b~cyclo-~3.3.03-octane-3-S-carboxylic acid 1 g of N~ S-carbethoxy-3-pher~yl-propyl) S-alanyl-2-azabicyclo-C3.3.0~-octane-3-S carboxylic acid from Example I ~5) was hydrolyzed (1 hour) and the m;xture was ~orked up~ as described under Example III.
Yield: 0.85 g m/e: 38 Example IV
N-t1-S-Carbethoxy~3-oxo-3-phenyl-propyl)-S-alan~ne benzyl ester 65.7 g of ethyl 3-phenyl-3-oxo-1~propen~1~ca~box~1ate ~e~hyl benzoylacrylate) were dissolved ~n 225 ml of ethano~, and 1 ml o~f triethylamine was added~ A solution of 70 9 of S-alan~ne benzyl ester in 90 ml of ethanol was rap~dly added dropwise at room temperature~ The mixture was stirred at room temperature for 2 hours and the solut~on was then cooled. The S,S-isomer crystallized out.

Yield: 94.3 9 Meltin~ point: 83 - 74C
~20 ~ ~ 17.8 (c = 1, CH30H) Example V
N-~l-S-Carbethoxy-3-oxo~3~phenyl-propyl)~S-alanille 0.5 g of the compound from Example IV was dis-solved in 40 ml of ethanol, 0.1 g of 10X Pd/C ~as added and hydrogenation was carried out at room temperature and 7~

under normal pressure.
Yield: 300 mg melting point: Z10 220~C
H-NMR tDMSO-d6): 1.0-1.4 tt,6H); 3.2-5.0 (m,8H);
7.2~8.2 tm,5H) 5 Example VI
Benzyl N-t1-S-carbethoxy-3-oxo-3-phenyl-propyl) S-alanyl-cis,endo-2-azab;cyclo-C3.3.0~-octane-3-S-carboxylate The compound was prepared from benzyl cis,endo-2-azabicyclo~C3.3.0~-octane-3-S-carboxylate hydrochloride and N-t1-S-carbethoxy-3-oxo-3-phenyl-propyl)-S-alanine from Example V, analogously to the process descr;bed ln Example I (4).
Example VII
H-t1-$-carbethoxy-3-oxo-3-phenyl-propyl)-S-alanyl-cis, endo-2-azabicyclo-C3.3~0~-octane-3-S-carboxylic acid 1 9 of the benzyl ester from Example ~I ~as dis-solved in 30 ml of ethanol ànd hydrogenated with 100 mg of Pd/C (10%) at room temperature and under normal pressure.
After one mole e~u;valent of hydrogen had been taken up, the hydrogenation was interrupte~. The catalyst ~as f~l-~ered of~ with suction and the solution was concentra~ed.
Y1eld: 600 mg of an o~l.
H-NMR tDMSO~Do): 1.0~3~0 tm,15H); 3.3-5~0 tm~10H);
7.2-8.1 tm,5H) Example YIII
-t1-S-Carbethoxy-3-phenyl-propyl)-S-lysyl-cis,endo-2-azabicyclo-C3.3~0~-octane-3-S-carboxylic acid dihydro-chloride t1) ~ -(1-S-Carbethoxy-3-oxo-3-phenyl-propyl)-N -benzyloxy-~g~
2~ -carbonyl-S-lysine benzyl ester 10 9 of ethyl 3-phenyl-3-oxo-l-p'ropen-l-carboxy~ate' ~ere d~ssolved 'in 100 ml o~ ethanol. 19.1 9 of N~-benzyl~
oxycarbonyl-S-lysîne benzyl ester and 0.2 g of tr;ethyl--S amine were added~ The solut;on was stirred at room tem-perature for 3 hours and ~as then concentrated in vacuo.
The oily residue ~31 9) ~as d;ssolved ;n isopropanol/di;
isopropyl ether and the solut;on ~as cooled. 13 ~ of Nd-S-carbethoxy-3-oxo-3-phenyl-propyL)-N~-ben~yloxycarbon-yl-S-lys;ne benzyl ester crystall;zed~
~20 - 3.5 tc = 1, CH30H) H-NMR ~CDCl3); 1.0-1.4 ~tr, 3H); 1.0~2.0 (m,9H);
2.0-2.6 (broad s., 1H); 2.9-3.9 ~m, 6H); 3.9-4.4 ~quadr. 2H); 4.6-4.9 ~broad s., 1H); S.0-5.2 ~double s.~ 4H9 7.1-8.1 ~m,15H) ~2) ~ -~1-S-Carbethoxy-3-phenyl-propyl)-N~-benzyloxy-carbonyl-S-lysine ' 4.0 g of the lysine benzyl ester derivat;ve pre-pared in Example VIII t1) were d;ssolved in 50 ml of glac;al acetic acid, and 0.6 9 of Pd/C ~10X) and ~.6 g of concentrated sulfuric ac;d were added~ llydrogenat1on w~s carr~ed out at room temperature and under normal pressure for 6 hours. The catalyst was then filtered off ~;th suc-tion and the ethanol;c solut;on was stirred with 1.4 g oFsol~d sod;um bicarbonate. The solut;on was concentrated on a rotary evaporator and the res;due was dissolved ;n ~ater. The aqueous phase was extr3cted with ethyl acetate and methylene chlor;de. The organ;c phases were d;scarded 2~

and the aqueous phase was evaporated to ~ryne~s in vacuo~
The res;due was extracted by stirring ~th me~hanol. After the methanol had been evaporated off~ an oily residue rema;ned~ which sol;dif;ed ~hen treated with diisopropyl e~her. Yield o~ ~-t1-S-carbethoxy--3-phenyl-propyl)-S-lys~ne: 2.0 9 H-NMR ~DzO): 1.0-1.4 (tr~ 3H); 1.0-2.5 (m, 9H~, 2.5-4~4 tm, 9H); 3.9-4.4 tq, 2H);
4.5-S.0 tm, 1H)~ 7~1-7.6 tm, 5H~
m/e: 336 3.4 9 of N~-t1-S-carbethoxy-3-phenyl-propyl)-S
lysine were d;Ssolved in 30 ml of methylene chloride and the solution was cooled to 0C. Wh;le cooling with ice, 2.1 9 of triethylamine were added, and 1.9 g of benzyl chloroformate were then added dropw;se. The mixture was st~rred at 0C for 1 hour and was then brought to room temperature. The methylene chloride solut~on was extrac-ted by shak1ng success;vely with water, sodium carbonate solution and water. After the product phase had been 2n dr~ed, 7t was concentrated and the oily residue ~as chromatographed over sll;ca gel uslng methylene chloride/
methanol. 2.0 9 of N~-t1-S-carbethoxy--3-phenyl-propyl)-N~benzyloxycarbonyl~S-lysine w~re obta;ned.
1H-NMR ~D20): 1.0-1.4 ~r, 3H); 1.0-2.5 (m, 9H);
2.5-4.4 tm, 9H~; 3.9-4.4 ~q, 2H);
4.5-5.0 tm~ 1H); 5.1 ~s, 2H); 7.1-7.5 tmr 1 OH) t3~ Benzyl N~-t1-S-carbethoxy-3-phenyl-propyl)-N~-benzyl-oxycarbonyl-Swlysyl-cis,endo-2-azabicyclo-C3.3..0~-octane-2~

3-S-carboxyiate a) 560 mg of benzyl 2-a~ab;cyGlo-C3.3.0~-octane-3-carboxylate hydrochloride prepared accordiny to Examp~e I
(3) were reacted with 940 mg of N~-~1-S-carbethoxy-3-phenyl~propyl)-N~-benzyloxycarbonyl~S~lysine prepared according to Example VIII ~2), analo~ously to Example I
~4). After the mixture had been worked Up9 1.5 g of an oil, uhich ~s a mixture of two diastereomeric co0pounds, were obtained.
The diastereomer mixture was separated ;nto the ~nd;vidual components by column chromato~raphy with silica ~el and cyclohexane/ethyl acetate 2:1 as the elut;n0 agent.
The ;somer eluted f;rst was the above compound. 0.6 g of an o;l ~as obtained. ~
1H-NMR ~CDCl3) (after replacement of H by D ~ith D20):
1~0 2.6 ~m~ 20H); 2~6-4.5 tm, 8H); 4.6-5.0 tm, 2H); 5.1-5.3 ~double s~, 4H~; 7~1-7.6 ~m, 15H) b) ~he later eluate gave 0~4 g of benzyl N~-~1-S-carbethoxy-3-phenyl-propyl)-N~benzyloxycarbonyl-S-lysyl-Z0 cis,endo-2-azabi cyc lo-C3.3.ûJ-octane-3-R-carboxylate~
H-NMR SCDCl3) ta~ter replacement of H by D ~th DzO):
1~0-206 tm, 20H); 2.6-4.4 tm, 8H); 4.5-5.0 tm, 2H); 5.1~5.3 ~double s., 4H); 7~1-7~5 tm, 15H) ~4) ~ -t1-S-Carbethoxy-3-phenyl-propyl)-S-lysyl-c~s,endo-Z-azab;cyclo-C3.3.0~-octane-3-S-carboxyl;c acid dihydro-chlor;de 500 mg of benzyl Nd-t1-S-carbethoxy-3~phenyl-propyl)-N-benzyloxycarbonyl-S-lysyl-c;s,endo-2-azabi cyGlo-~3.3.D~octane-3-S-carboxylate from Example VIII (3a) 7Z~
- 24 ~
~ere dissolved ;n 20 ml of eth~nol and were debenzylated hydrogenolytically under normaL pressure, ~ith add;t;on of 0~1 g of 15X Pd/C. ~Ihen the uptake of hydrogen had ended, the catalyst was filtered off, ethanol1c hydrogen chloride solution ~as added to the ethanol;c soLut;on until a pH of 1 ~as reached, and the ethanol was evaporated off in vacuo.
D;;sopropyl ether was added to the res;due~ where~pon the product sol;d;fied. 200 mg were obtained.
1H-NMR of the beta;ne (CDCl3, after replacement of H
by D with D20): 1.0-2.5 ~m, 20H); 2.6-4.4 tm, 8H~; 4.4-5.1 ~m, 2H); 7.2 (s, 5H) Example IX
N ~ S-Carbethoxy-3-phenyl propyl)-S-lysyl-cis,endo-2-azabicyclo-C3.3.0~-octane-3-R-carboxyl;c ac;d d;hydro-chlor;de 0.3 mg of the correspond;ng benzyl ester fromExample VIII t3 b) were reacted, and the m;xture worked up, analogously to Example VIII (4). 110 mg of the car-boxylic ac;d ~ere obtained ;n the form of the dihydro chlor;de.
H-NMR of the betaine ~CDCl3, af~er replacement of H
by D with D20): 1.0-2.o (m~ 20H); 2.b-4.4 tm, 8H);
4.1-5~1 ~m, 2H); 7.2 ~s, SH) Example X
N -~1-S-Carboxy-3-phenyl-propyl~-S-lysyl-c;s,endo-2-aza-b;cyclo-C3.3.0~-octane-3-S-carboxyl;c acid hydrochloride O.S 9 of N -~1-S-carbethoxy-3-phenyl-propyl)-S-lysyl-cis,endo-2-a~abicyclo-C3.3~0~-octane-3 S-carboxylic acid dihydrochloride from Example VIII ~4) was suspended 7~

~n 2n mL of dimethoxyethane. Aqueous 4 N KOH was add~d unt;~ a pH of 9-10 ~as reached~ Th~ mixture ~as st~rred for half an hour. It ~as then adjusted to pH 4 ~ith hydroch~oric acid and concentrated to dryness in vacuo~
th~ ~eçidue was taken up ln ethyl acetate and the m1xtur0 ~as fi~ered. The ethy~ acetate soLution ~as concentrated and the res;due was tr;turated w;th di~sopropyl ether, ~hereupon ;t sol~d;f;ed.
Yield: 0.35 g ~H-NMR ~Dz0~ 1.2-2.5 (m~ 17H); 2~5-4.5 tm, 6H);
4.5-5.0 tm, 2H); 7.2 ~s~ 5H) Example XI
S-Carboxy-3-phenyl-propyl)-S-lysyl-c;s,ondo-2-aza-b;cyclo-C3.3.0J~octane-3-R-carboxylic ac;d hydrochloride 500 mg o~ N~-~1-S-carbethoxy-3-phenyl-propyl)-S-lysyl-c;s,endo-2-azab;cyc~o-~3.3.0~-octane-3-R carboxylic acid d;hydrochlor;de from Examp~e IX ~ere hydrolyzed, and the mixture ~as work~d up, analogous~y to Example X.
Y;eld. 0.32 0 1H-NMR ~D20): 1.2-2.5 tm, 17H); 2.5-4~5 tm~ 6H);
4.5-5.0 ~m, 2H)~ 7.2 ~s, 5H) Example XII
N-(l-S-Carbethoxy-3-phenyl-propyl)-0-ethyl- ~tyrosyl-cis, endo-2-aza bicyclo~3.3.0] octan-3-S-carboxylic acid ~l) N-(l~R,S-carbethoxy-3-phenyl-propyl)-0-ethyl-S-tyrosine benzyl ester Analogously to example IV, 24g ethyl benzoyl-acrylate dissolved in lOO ml ethanol were reacted with 30g O-ethyl-S-tyrosine benzyl ester in the presence of 0.5 ml triethylamine.

~7~

The solution was concentrated, the resudue was digested with diethylether¦petroleum ether (1:1) and dried in vacuo. 42g of the RS, S-compound were obtained.
(2) N-~l-R,S-carbethoxy-3-phenyl-propyl)-O-ethyl-S-tyrosine 40g of the product from (1) were dissolved in 800 ml glacial acetic acid and the solution was hydrogenated under 100 bar and room temperature in the presence of 4g Pd/C (10 percent).
After the crude product had been chromatographedover silica gel in the solvent ethyl acetate/cyclohexane 1:3 and the solution had been concentrated to dryness, 25g of the title compound were obtained, which proved to be almost homogen by thin layer chromatography. Melting point: 205-213 C.
Analysis:
C23 H39 NO~ (399.5) Calculated: 69.15 C 7.31 H 3.50 N
Found: 69.5 7.4 3.3 (3) N-(l-S-carbethoxy-3-phenyl-propyl)-0-ethyl-S-tyrosyl-cis, endo-2-aza bicyclo[3.3.0]-octan-3-S-carboxylic acid Analogously to example I (4), 5g of the ~ree benzyl ester, obtained from example I (3) by treating with alkali and extracting with diethylether, were reacted with 8g of the compound from example XII (2) and 4.4g dicyclohexyl-carbodiimide in the presence of 2.7g l-hydroxy benzotriazole. After subsequent chromatography as described in example I (4) 2.9g of an oil, which is the intermediate benzyl ester, were obtained.
lH-HMR- and mass spectra were in accordance with the given structure.

r The benzyl ester was dissolved in 50 ml ethanol, Pd ~C) was added and hydrogenation was carried out under normal pressure.
The mixture was filtered, the filtrate was concentrated~ the residue was digested and dried in vacuo. Yield: 2.2g.
lH-NMR (CDCI3): 1.2-3.0 (M, l5H), 1.27 (T, 3H), 1.4 (T,3H), 3.0-4.3 (M, 4H), 3.8-4.2 (M, 4H), 6.5-7.1 (2D, 4H), 7.3 (S, 5H).
Example XIII
N-(l-S-Carbethoxy-3-phenyl-propyl)-O-methyl-S-tyrosyl-cis, endo-10 2-aza bicyclo ~3.3.0]octan,3-S-carboxylic acid The compound was prepared from O-methyl-S-tyrosine benzyl ester analogously to the process described in example XII. The lH-NMR spectrum is in accordance with the given structure.

Claims (3)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for the preparation of a compound of the formula II
(II) wherein R1 denotes hydrogen, allyl, vinyl or a side-chain of a naturally occurring .alpha.-aminoacid R1-CH(NH2)-COOH, which may be protected, R2 denotes hydrogen, (C1-C6)-alkyl, (C2-C6)-alkenyl or aryl-(C1-C4)-alkyl, Y denotes hydrogen or hydroxyl and Z denotes hydrogen, or Y and Z together denote oxygen, and X denotes (C1-C6)-alkyl, (C2-C6)-alkenyl or (C5-C9)-cycloalkyl, or (C6-C12)-aryl, which can be mono-, di- or tri-substituted by (C1-C4)-alkyl, (C1-C4)-alkoxy, hydroxyl, halogen, nitro, amino, (C1-C4)-alkylamino, di-(C1-C4)-alkylamino or methyl-enedioxy, or denotes indol-3-yl, in which (a) if X is aryl, an aryl methyl ketone X-CO-CH3 is reacted with a glyoxylic acid ester CHO-CO2R2 and an .alpha.-aminoacid ester H2N-CHRl-CO2W', wherein W' is a radical which can be split off under basic or acidic conditions or by hydrogenolysis and R2 does not denote benzyl or nitrobenzyl if W' is benzyl, to give a compound of the formula IV

(IV) wherein X, W', R1 and R2 have the meanings given above, or (b) a keto-acrylic acid ester X-CO-CH=CH-CO2R2 is reacted with an .alpha.-aminoacid ester H2N-CH(R1)-CO2W' to give a compound of the formula IV, the compound obtained according to (a) or (b), if W' is a radical which can be split off under acidic or basic conditions, may be subjected to acidic or basic ester cleavage, or, if W' is benzyl or nitrobenzyl, R2 being equal to benzyl or nitrobenzyl, the compound may be converted into the carboxylic acid by hydrogenolysis and the product hydrogenated to a compound of the formula II wherein X, R1 and R2 have the above meanings, Y denotes hydrogen or hydroxyl and Z
denotes hydrogen, or a lower alkyl ester thereof, which, if appropriate, can also be subjected to acid-catalyzed ester cleavage.

2. A compound of the formula IV as defined in claim 1, whenever obtained by the process of claim 1, or by an obvious chemical equivalent thereof, wherein X, R1 and R2 have the meanings given in claim 1, W' denotes a radical which can be split off by basic or acidic hydrogenolysis and R2 is not benzyl or nitrobenzyl if W' is benzyl.

3. The process as claimed in claim 1, wherein W' is benzyl or tert. butyl.