IE42961B1 - Cephalosporin compounds - Google Patents

Abstract

The compounds of this invention are cephalosporins having a thienyl- or tetrazolylacetamido substituent at the 7-position and a carboxy or carbamoyl substituted triazolyl- or tetrazolylthiomethyl group at the 3-position of the cephem nucleus. The compounds have antibacterial activity.

Description

This invention relates to a new series of cephalosporin compounds which .ve antibacterial activity when administered parenterally, to processes for 'eparing them, to pharmaceutical compositions, and to use of the compounds. In rticular, the compounds of this invention are characterized by having a irboxy- or carbamoyl- substituted trizolyl or tetrazolythiomethyl group at le 3-position of the cephem nucleus.

The compounds of this invention are represented by Formula I: FORMULA I.

Which: R^ is thienyl or tetrazolyl; and Het is selected from -242961 Η CHR2)-COR3 Η amino, or a non-toxic pharmaceutically acceptable salt thereof.

As used herein, the term lower alkyl refers to groups having from one to four carbon atoms, especially methyl and ethyl.

Preferred compounds of this invention are represented by Formula I in which Advantageous compounds of this invention are represented by Formula I in which 3 2 Het is tetrazolyl substituted with -(CHR )mC0R where R is hydrogen» m is one to five and R is hydroxy or amino.

Particularly preferred are the compounds 7 -(2 - thienyl - acetamido) -3- (1carboxymethyltetrazol - 5 - ylthiomethyl) - 3 - cephem -4- carboxylic acid, 7 (2-thienylacetamido) -3-(1-(2- carbamoylethyl)tetrazol -5- ylthiomethyl] - 3- cephem - 4 - carboxylic acid, 7-(1- tetrazolylacetamido) -3-(1carboxymethyltetrazol - 5 - ylthiomethyl) - 3 - cephem - 4 - carboxylic acid, 7 f**' (2 - thienyl acetamido) - 3 - £[ - (2 - carboxyethyl)tetrazol - 5 - ylthiomethyTj 9- 3 - cephem - 4- carboxylic acid, and 7 - (1 - tetrazolylacetamido) - 3 - (l (2 - carboxymethyl)tetrazol 5 - ylthiomethyl] -3- cephem -4- carboxylic acid.

Cephalosporin derivatives having a thienyl acetamido or tetrazolylacetamido group at the 7 - position are known, for example in British Specifications Nos. 1,206,305 and 1,295,841, In a process of the invention, the compounds of Formula I are prepared by acylation of a 7 - amino - 3 - substituted triazolyl- or tetrazolylthiomethyl -361 cehpalosporin of Formula II: CHgSHet FORMULA II. ι which: Het is as hereinbefore defined; R^ is hydrogen or-an ester-forming protecting group, with an activated thienyl tetrazolyl- acetic acid, followed, if necessary, by removal of the protecting •oup. The carboxylic acid group of the thienyl- or tetrazolyl-acetic acid is :tivated by any of the standard methods such as conversion to a mixed anhydride, ;id chloride, acid imidazolide or activated ester. In addition, a reagent ich as dicyclohexylcarbodiimide can ba used provided that the carboxyl group ι the cephem nucleus is protected with an easily removable protecting group ich as a benzhydryl,t -butyl, trichloroethyl, benzyl, benzy1oxymethyl,p-nitrotenyl ,p-methoxyphenyl ,p-methoxybenzyl or p-nitrobenzyl group.

Alternatively, the compounds of Formula I are prepared by acylating 7 - amino.‘phalosporanic acid with a thienyl- or tetrazolyl- acetic acid R'CHgCOOH and ien displacing the 3-acetoxy group with the required substituted triazole- or itrazolethiol HS Het.

The protecting group can be removed according to methods well known to the •t, such as with trifluoroacetic acid when a t-butyl protective group is used.

The resulting trifluoroacetate salt may be converted to the free acid by ians of a basic ion exchange resin such as AmberTite IR-45 (Amberlite is a -44 2 9 61 the method of Hoover and Day p Registered Trade Mark) or by basicificetion of an aqueous solution of the salt.

The thienyl- and tetrazolyl- acetic acid starting materials are known or are prepared by known methods. 7-(2- Thienylacetamido)cephalosporanic acid and 7 - (2-tetrazolylacetamido)cephalosporanic acid are also known (U.S. Patent No. 3,516,997).

The 7 - amino - 3 - substituted triazolyl- and tetrazolylthiomethyl-cephalosporin starting materials of Formula II are prepared by reaction of 7 - aminocephalosporanic acid and a substituted triazole- or tetrazole-thiol.

The substituted 1,2,3,-criazole-thioIs not known to the art are prepared by rearrangement of a correspondingly substituted amino-thiadiazole according to the procedure of Goerdeler and Gnad fchem. Ber. 99:1618 (1966)j, by conversion of a suitably substituted hydroxy-1,2,3-triazoIe to the corresponding thiol by . Amer. Chem. Soc. 78:5832 (1956)j or by reaction of an acetylene-carboxylic acid with an azide and subsequent decarboxylation and conversion to the corresponding thiol.

The substituted tetrazole-thiols where R is hydroxy are prepared by reaction of an isothiocyanate, for example ethyl isothiocyanatoacetate, or an N-alkyldithiocarbamate, such as methyl 2-carboxyethyldithiocarbamate, with an azide such as sodium azide. When R is amino, lower alkylamino or di(lower alkyl)amino the tetrazolethiols are prepared from the corresponding tetrazole-thiols where R is hydroxy by standard methods for the preparation of amides from acids, for' example, by reaction of a tetrazole-thiol where R is hydroxy with 1,1-carbonyC £ G c Idiimidazole and ammonia or an amine of the formula NHR R where R and R are each hydrogen or lower alkyl, or by conversion of the tetrazole-thiol where R is hydroxy to the corresponding acid chloride with subsequent reaction of the 5 A acid chloride with ammonia or an amine (NHR R ). The tetrazole-thiols are also prepared by conversion of a suitably substituted hydroxy-tetrazole to the corresponding thiol by the method of Hoover and Day Q. Amer. Chem. Soc. 78:5832 (1956)} : The compounds of this invention are capable of forming salts with, for example, the alkali metals such as sodium or potassium, the alkaline earth metals such -52951 calcium or with the ammonium cation. These salts are prepared by standard nethods using a wide variety of non-toxic pharmaceutically acceptable acids and jases known in the art and are also considered as objects of this invention.

It will be recognised that due to the potentially asynsnetric carbon in the i-heterocyclic side chain of Formula I, optical isomers may exist. All of the isomers, including separated isomers and mixtures thereof, are included within :he scope of this invention.

The compound.s of Formula I have antibacterial activity against both Gramlositive and Gram-negative organisms. They also exhibit high serum levels and erum half-life values. Minimum inhibitory concentrations (MIC's) ranged from t .2 to>200u./ml. in in vitrio testing. These results are shown in Table 1 elow for a number of compounds of Formula I. in vivo mouse protection data re given in Table 2. Compound names corresponding to numbers are given in able 3. -642961 TABLE 1 7· 29G1 TABLE 2 Compound ED50· in vivo(mg./kg.) E. coli 12140 Kleb. pneumo. 4200 s.c. p.o. s.c. p.o. 1 21.2 - 3.9 - 2 1.56 46 1.56 35 3 7.2 35 1.0 40 4 0.4 >50 1.8 >50 5 21.2 - 25 6 • 1.12 50 1.56 - 7 . - - - - TABLE 3 Compound Nuiitber Compound Name 1 7-(2-thi enylacetami do)-3-(1-carboxymethyl tetrazol-5-y1thi omethyl)-3cephem-4-carboxylic acid 2 7- (2-thi enyl acetami do) -3- - (2carbamoylethyl)tetrazol-5-y1thi 0methylJ-3-cephem-4-carboxylic acid 3 7- (2-thi enyl acetami do) - 3-0 -(2carboxyethyl)tetrazol-5-ylthi omethylj 3-cephem-4-carboxylic acid 4 7-(1-tetrazolylacetami do)-3-(1carboxymethyltetrazol-5-y1th i omethyl)3-cephem-4-carboxylic acid 5 7-(1-tetrazolylacetamido)-3-(5-carboxymethyl-1,2,4-tri azol-3-y1thi omethyl)3-cephem-4-carboxylic acid 6 7-(1 -tetrazolyl acetami do) -3-fl - (2carboxyethyl)tetrazol-5-ylthi omethylj 3-cephem-4-carboxylic acid 7 7- (2-thi enyl acetami do) -3-0-(10- carbamoyldecyl)tetrazol-5-ylthi omethylj 3-cephem-4-carboxylic acid Pharmaceutical compositions having antibacterial activity which comprise a pharmaceutical acceptable carrier and a compound of Formula I and methods of -842961 treating or preventing bacterial infections in non-human mammals by administering a compound of Formula I in a non-toxic amount sufficient to treat or prevent said infection are also objects of this invention. The administration may be by parenteral injection such as subcutaneously, intramuscularly or intravenously.

The injection of suitably prepared sterile solutions or suspensions containing an effective, non-toxic amount of the new cephalosporin compound is the preferred route of administration.

The compounds of Formula I are formulated and administered in the same manner as other cepahalosporins in dosages of from 250 to 1000 mg., with the total daily dosage being from 1 to 6 g. The precise dosages are dependent upon the age and weight of the subject and on the infection being treated and can be determined by those skilled in the art, based on the data disclosed herein compared with that available to the art attained with known cephalosporins.

The following examples illustrate the invention but are not to be construed as limiting the scope thereof. Temperatures are in degrees Centrigrade unless otherwise stated.

EXAMPLE 1. 7- (1 -Tetrazolyl acetamido) -3- (5-carboxymethyl -T',2,4-tri azol -3-yl thiomethyl )-3cephem-4-carboxylic acid.

To a solution of 1.05 g. (12.5 mmol.) of sodium bicarbonate in 30 ml. of water was added 1.36 g. (7.5 mmol.) of 3-carboxymethyl-l,2,4-triazo1-5-thiol sodium salt, prepared by addition of an equivalent amount of a sodium hydroxide solution to a solution of 3 -carboxymethyl -1,2,4 - triazol -5- thiol in an aqueous ethanol, and 1.91 g. (5.0 mmol.) of 7 - (1 - tetrazolylacetamido) cephalosporanic acid. The reaction mixture was heated at 67.5° for four hours while maintaining the pH at 7.6 by addition of glacial acetic acid. The mixture was cooled to 20°, acid was added to bring the pH to 3.5 and the resulting solution was lyophilized and the residue triturated with ethanol. The product was dissolved in 15 ml. of absolute methanol and a 0.196N solution methoxide in methanol was added until ca. pH 6.0. Ethyl acetate was then added to the solution and the precipitate was collected and dried in vacua to give 7 - (1 - tetrazoly-9961 icetamido) -3-(5- carboxymethyl - 1,2,4 - triazol - 3 - ylthiomethyl) - 3 iphem-4-carboxylic acid di sodium salt. 15H11N9°6S2 * 2Na * 3·5H2° ilculated: 31^.98% C; 3.74% H; 21.18% N; 10.54% S iund: 32.53% C;' 3.14% H; 20.72% N; 10.55% S 7-(1- Tetrazolylacetamido) -3-(5- carboxymethyl - 1,2,4 - triazol - 3Ithiomethyl) - 3‘ cephem - 4 - carboxylic acid disodium salt is dissolved in a inimutn amount of water to which ethyl acetate is added. While stirring, 3N /drochloric acid is added until the solution is acidified to pH 2.5. The layers re separated, the aqueous phase is extracted with ethyl acetate and the combined «tracts are washed with water, dried (MgSO^) and evaporated to dryness to give ie title compound.

EXAMPLE 2. 7-(2-Thienylacetami do)-3-(5-carboxymethyl-1,2,4-triazol-3-ylthiomethyl)-3cephem-4-carboxylic acid.

When an equivalent amount of 7 - (2 - thienylacetamido)cephalosporanic acid ; substituted in the procedure of Example 1 for 7-(1- tetrazolylacetamido)iphalosporanic acid, the title compound is obtained.

The title compound may be converted to the corresponding di sodium salt by idition of sodium methoxide solution as described in Example 1.

EXAMPLE 3. 7-(1-Tetrazolylacetami do)-3-(4-carboxy-l,2,4-tri azol-5-y1thi omethyl) -3cephem-4-carboxylic acid.

To a solution of 4.6 g. (0.20 mol.) of sodium and 250 ml. of absolute ethanol is added under a nitrogen atmosphere 8.65 g. (0.05 mol.) of 5 -amino -4- carbihoxy - 1,2,3 - thiadiazole. The reaction mixture was stirred for one hour, 5 ml r water was added and the mixture was refluxed for 12 hours. After cooling, the ixture was filtered and the solid product was washed with ethanol and ether and ”ied to give 4 - carboxy - 1,2,3 - triazole -5- thiol trisodium salt.

Acidification of an aqueous solution of 4 - carboxy - 1,2,3 - triazole - 5 liol trisodium salt gives 4 - carboxy - 1,2,3 - triazole - 5 - thiol. The -1042902 corresponding mono-sodium salt is prepared as described in the procedure of Example 1.

Substitution of an equivalent amount of 4 - carboxy - 1,2,3 - triazole - 5thiol salt in the procedure of Example 1 for 3 - carboxymethyl - 1,2,4 - triazole - 5-thiol sodium salt gives the title compound.

EXAMPLE 4, 7-(1-Tetrazolylacetami do)-3-(4-carbamoy1-1,2,3-tri azol-5-ylthiomethyl)-3cephem-4-carboxylic acid.

Reaction of 7 - (1 - tetrazclylacetamido)cepbalGsporanic acid, 4 - carbamoyl1,2,3 - triazole - 5 - thiol sodium salt, prepared from 4 - carbamoyl - 1,2,3 triazole- 5 - thiol as described above, and sodium bicarbonate according to the procedure of Example 1 gives the title compound.

EXAMPLE 5. 7-(l-Tetrazolylacetamido)-3- 4-(2-carboxyethyI)-l,2,3-triazol-5-ylthiomethyl -3cephem-4-carboxylic acid.

To a solution of 1.725 g. (75 mmol.) of sodium in 50 ml. of absolute ethanol was added 6.0 g. (45 mmol.) of benzyl azide and 12.3 g (50 mmol.) of diethyl 2-(2- carbomethoxyethyl)malonate. The reaction mixture was refluxed for 12 hours, and cooled and evaporated to dryness. Water (100 ml.) was added and the mixture was heated while maintaining the pH at 12. The aqueous mixture was extracted with ethyl acetate and the aqueous phase was acidified with 3N hydrochloric acid and extracted with ethyl acetate. The ethyl acetate solution was evaporated to dryness to give 1 - benzyl -4- (2 - carboxyethyl) -5- hydroxy 1,2,3 - triazole.

- Benzyl -4-(2- carboxyethyl) -5- hydroxy - 1,2,3 - triazole (5.0 g., 0.02 mol.) was suspended in 300 ml. of ethanol. Anhydrous hydrogen chloride gas was bubbled into the suspension for 30 minutes and the mixture was then heated on a steam bath for 20 minutes. The solution was cooled and evaporated to dryness to give a residue which was dissolved in 300 ml. of ethyl acetate. The ethyl acetate solution was washed with water, dried (MgSO^) and evaporated to dryness. Trituration with hexane containing a little acetone gave 1 - benzyl -4- (2 -11)61 arbethoxyethyl) - 5- hydroxy - 1,2,3 -triazole.

A solution of 0.63 g. (2.3 mmol.) of 1 - benzyl - 4 - (2 - carbethoxyethyl) - 5- hydroxy - 1,2,3 - triazole in 0.70 g. (3.5 nmol.) of phenyl phosphoric dichloride was heated under a nitrogen atmosphere at 160° for 1.5 hours. Water (2ml.) and 2 ml. of chloroform were added to the reaction mixture and it was stirred at 5° while 6 ml. of 5% aqueous sodium bicarbonate was added. The nixture was extracted with chloroform and the extract was dried (NagSO^) and evaporated to dryness to give 1 -benzyl- 4-(2- carbethoxyethyl) - 5 - chloro 1,2,3 - triazole.

A solution of 0.54g.(0.01 mol) of sodium methoxide in 50 ml. of absolute ethanol is saturated with hydrogen sulfide. 1 - Benzyl -4- (2 - carbethoxyethyl) - 5 - chloro- 1,2,3 - triazole (2.9 g., 0.01 mol) is added and the reaction is 'efluxed for 24 hours. The cooled mixture is evaporated to dryness to give 1 >enzyl -4-(2- carboxyethyl) - 1,2,3 - triazole -5- thiol sodium salt. Acidifi:ation of an aqueous solution of the triazole - thiol salt as previously lescribed gives 1 - benzyl -4-(2- carboxyethyl) - 1,2,3 - triazole -5- thiol.

- Benzyl -4- (2 - carboxyethyl) - 1,2,3 - triazole -5 - thiol (1.1 g., 4 imol.) is suspended in 50 ml. of anhydrous liquid ammonia and sodium is added intil a permanent blue color results. The reaction mixture is stirred for 40 linutes, then allowed to. warm to ambient temperature while the ammonia evaporates, he residue is triturated with ether and the solid formed is collected and iissolved in water. The aqueous solution is acidified and extracted with thyl acetate. The extract is dried (MgSO^) and evaporated to dryness to give -(2- carboxyethyl) - 1,2,3 - triazol- 5 - thiol. The corresponding sodium alt is prepared as described in Example 1.

Substitution of 4- (2 - carboxyethyl) - 1,2,3 - triazole - 5 -thiol sodium alt in the procedure of Example 1 for 3 - carbomethyl - 1,2,4 - triazole - 5 hiol sodium salt gives the title compound.

EXAMPLE 6.

Use of equivalent amounts of diethyl 2 - carbethoxy - methylmalonate and iethyl 2-(3- carbethoxypropyl)malonate, respectively, in the procedure of -1242961 Example 5 in place of diethyl 2-(2- carbomethoxyetnyl)malonate, gives 4 carboxymethyl - 1,2,3- triazole - 5 - thiol and 4-(3- car^oxypropyl) - 1,2,3 - triazole -5- thiol. The corresponding sodium salts are prepared as described in the procedure of Example 1.

Use of 4 - carboxymethyl - 1,2,3 - triazole -5- thiol sodium salt and 4 (3- carboxypropyl) - 1,2,3 - triazole -5- thiol sodium salt in the procedure of Example 1 in place of 3 - carboxymethyl - 1,2,4 - triazole -5 thiol sodium salt gives, respectively, 7-(1- tetrazolylacetamido) -3- (4 - carboxymethyl - 1,2,3 - triazol - 5- ylthiomethyl) - 3 - cephem - 4 - carboxylic acid and 7-(1- tetrazolylacetamido)- 3 - 4-(3- carboxypropyl) - 1,2,3 - triazol -5- ylthiomethyl -3- cephem - 4- carboxylic acid.

EXAMPLE 7.

To a solution of 13.8 g. (0.6 mol.) of sodium in absolute ethanol is added a solution of 96 g. (0.6 mol.) of diethyl malonate in 500 ml. of ether. The mixture is cooled and 117.1 g. (0.6 mol.) of 2 - bromo - 2 - methyl propionic acid ethyl ester is added. The reaction mixture is warmed for two hours, then stirred at ambient temperature for 48 hours. Acetic acid and water are added, the layers are separated and the etheral phase is washed with water, dried (MgSO^) and evaporated to dryness to give diethyl 2-(1- carbethoxy 1 - methylethyl)malonate.

When an equivalent amount of the following bromoesters: - bromo - 2,2 - dimethyl propionic acid methyl ester 5 - bromo -2-methylvaleric acid methyl ester 2 - bromo-2-ethylbutyric acid methyl ester is used in place of 2 - bromo - 2 - methyl propionic acid ethyl esters in the reaction with diethyl malonate, the substituted malonates listed below are obtained: diethyl 2-(2- carbomethoxy-2-methylpropyl) -malonate diethyl 2-(4- carbomethoxynentyl )malonate diethyl 2-(1- carbomethoxy-l-ethylpropy1)malonate Substitution of a substituted malonate named hereinabove in place of -1331 diethyl 2-(2- carbomethoxyethyl)malonate, as a starting material in the procedure of Example 5, gives the following triazole-thiols as products: 4-(1-carboxy-1-methyl ethyl)-1,2,3-tri azole-5-thiol 4-(2-carboxy-2-methylpropyl)-1,2,3-tri azole-5-thi ol 4-(4-carboxypentyl)-1,2,3-tri azole-5-thi ol 4-(1-carboxy-1-ethyl propyl )-1,2,3-tri azole-5-thi ol Use of a substituted triazole-thiol sodium salt, prepared as described above, in the procedure of Example 1 in place of 3 - carboxymethyl - 1,2,4 triazole - 5- thiol sodium salt gives the following 7-(1- tetrazolylacetamido) - 3 - (substituted triazolyl)thiomethyl-cephalosporin compounds: 7-(1- tetrazolylacetamido) -3- - (1 - carboxy - 1 - methylethyl)- 1,2,3 - triazol -5- ylthiomethyl^-3-cephem-4-carboxy1ic acid 7-(1- tetrazolyl acetamido') -3- ^4-(2- carboxy - 2 - methylpropyl)- 1,2,3 - triazol-5-ylthiomethyl] -3-cephem-4rcarboxylic acid 7-(.1- tetrazolyl acetamido) -3- ^-(4- carboxypentyl) - 1,2,3 triazol-5-ylthiomethylj -3-cephem-4-carboxylic acid 7-(1- tetrazolyl acetamido) -3- β - (1 - carboxy -I- ethylpropyl)- 1,2,3 - triazol -5-ylthiomethyjJ -3-cephem-4-carboxylic acid.

EXAMPLE 8. 7-(l-Tetrazolylacetamido)-3-(4-N-methylcarbamoyl-l,2,3-triazol -5-ylthiomethyl )3-cephem-4-carboxylic acid.

A solution of 7.2 g. (44 mmol.) of 1,1 - carbonyl - diimidazole in 110 ml. of dry tetrahydrofuran and 20 ml. of dimethyl formamide is added to a solution of 7.7 g. (43.8 mmol.) of 4 - carboxy - 1,2,3 - triazole -5- thiol in 110 ml. of dry tetrahydrofuran and 20 ml. of dimethyl formamide. Tetrahydrofuran saturated with methylamine is added and the reaction mixture is stirred at 25° for 12 hours. The mixture is evaporated to dryness, the residue is diluted with 200 ml. of water and the resulting solution is adjusted to pH 2-3 by addition of sulfuric acid. The aqueous solution is lyophilized and the residue extracted with acetone to give 4-N-methylcarbamoyl-1,2,3triazole-5-thiol. -144 2961 Reaction of 4 - N - methylcarbamoyl - 1,2,3 - triazole - 5- thiol sodium salt, prepared from the thiol as described above in Example 1, with 7 (1 - tetrazolylacetamido)cephalosporanic acid as described in the procedure of Example 1 gives the title compound.

EXAMPLE 9.

When ethyl amine, propylamine or butyl amine is substituted for methyl amine in the procedure of Example 8, the following triazole-thiols are prepared: 4-N-ethylcarbamoyl-1,2,3-tri azole-5-thi ol 4-N-propylcarbamoyl-1,2,3-triazole-5-thiol 4-N-butylcarbamoyl-1,2,3-triazole-5-thiol.

Reaction of the sodium salt of a triazole-thiol listed above, prepared as described in Example 1, with 7-(1- tetrazolylacetamido)cephalosporanic acid or 7 - (2-thieny1acetamido)cephalosporanic acid as described hereinabove, gives the following compounds of this invention: - (1- tetrazolylacetamido) -3- (4 - N - ethyl carbamoyl - 1,2,3 triazol- 5 - ylthiomethyl)-3-cephem-4-carhoxylfc acid - (1- tetrazolylacetamido) -3- (4 - N - propyl carbamoyl - 1,2,3triazol- 5 - ylthiomethyl)-3-cephem-4-carboxylic acid 7-(1- tetrazolylacetamido) -3- (4 - N - butyl carbamoyl - 1,2,3 triazol- 5 - ylthiomethyl)-3-cephem-4-carboxylic acid 7-(2- thienyl acetamido) -3- (4 - N - ethyl carbamoyl - 1,2,3triazol- 5 - ylthiomethyl) -3-cephem-4-carboxylic acid 7-(2- thienyl acetamido) -3- (4 - N - propyl carbamoyl - 1,2,3triazol- 5 - ylthiomethyl) -3-cephem-4-carboxylic acid 7-(2- thienyl acetamido) -3- (4 - N - butyl carbamoyl - 1,2,3triazol- 5 - ylthiomethyl) -3-cephem-4-carboxylic acid.

EXAMPLE 10. 7-(1-Tetrazolylacetamido)-3-(5-N,N-dimethyl carbamoyl methyl-1,2,4-tri azol 3-ylthiomethyl)-3-cephem-4-carboxylic acid.

To a solution of 5.34 g. (33.8 mmol.) of 3 - carboxymethyl - 1,2,4 triazole-5 - thiol in 75 ml. of dry tetrahydrofuran and 20 ml. of dry -15)61 limethylformamide is slowly added a solution of 5.49 g. (33.9 mmol) of 1,1:arbonyl di imidazole in 95 ml. of dry dimethylformamide. The reaction mixture s stirred for 35 minutes, then 250 ml. of tetrahydrofuran saturated with limethylamine is added to the suspension and it is stirred at 25° for 12 hours, 'he mixture is concentrated to about 200 ml. and tetrahydrofuran and ether are :dded. The precipitate is collected by filtration and disolved in 170 ml. of rater. The aqueous solution is acidified to pH 2.0 by addition of 6N sulfuric cid and extracted with ethyl acetate. The ethyl acetate solution is evaporated ;o dryness and triturated with ether to give 3 - N,N - dimethyl - carbamoylethyl-1,2,4-triazole-5-thiol.

Reaction of 3 - N,N - dimethylcarbamoylmethyl - 1,2,4 - triazole - 5 - thiol odium salt, prepared from the thiol as described in Example 1, with 7-(1etrazolylacetamido)cephalosporanic acid as described therein gives the title ompound.

EXAMPLE 11, When di ethyl amine, dipropyl amine or dibutyl amine is substituted for dimethyl mine in the procedure of Example 10, the following triazole-thiols are prepared: 3-N,N-di ethyl carbamoylmethyl-1,2,4-triazole-5-thi ol 3-N,N-dipropylcarbamoylmethyl-1,2,4-triazole-5-thiol 3-N,N-dibutylcarbamoylmethyl-l,2,4-triazole-5-thiol.

Reaction of the sodium salt of a triazol e-thiol listed above, preoared as escribed in Example 1, with 7-(1- tetrazolylacetamido)cephalosporanic acid r 7 - (2-thienylacetamido)cephalosporanic acid as described above gives the ollowing compounds of this invention, respectively: 7-(1-tetrazolylacetami do)-3-(5-N,N-diethylcarbamoylmethyl-1,2,4-tri azol -3-ylthiomethyl)-3-cephem-4-carboxylic acid 7-(1-tetrazolylacetami do)-3-(5-N,N-di propyl carbamoylmethyl-1,2,4-tri azol -3-ylthiomethyl)-3-cephem-4-carboxylic acid 7-(1-tetrazolylacetami do)-3-(5-N,N-di butyl carbamoylmethyl-1,2,4-triazol -3-ylthiomethyl)-3-cephem-4-carboxylic acid 7-(2-thi enylacetami do)-3-(5-N,N-di ethylcarbamoylmethyl-1,2,4-triazol -1642961 -3- ylthiomethyl) - 3 - cephem -4 - carboxylic acid 7-(2-Thi enylacetami do)-3-(5-N,N-dibutylcarbamoyl methyl-1,2,4-tri azol -3-ylthiomethyl)-3-cephem-4-carboxylic acid.

EXAMPLE 12. 7-(2-Thi enylacetami do)-3-(1-carboxymethyltetrazol-5-ylthi omethyl)-35 cephem-4-carboxylic acid.

Glycine (60 g., 0.8 mol.) was added to a cooled (5-10°) solution of 89.6 g, (1.6 mol.) of potassium hydroxide in 200 ml, of water. After complete dissolution 60.8 g. (0.8 mol.) of carbon disulfide was added and the reaction mixture was stirred at 25° for three hours. A solution of 113.6 g. (0.8 mol.) of methyl iodide in 200 ml. of ethanol was added while maintaining the temperature at 2530°. The reaction mixture was stirred for two hours at 25°, then concentrated in vacuo and the remaining aqueous phase was made basic (pH 8.0) with aqueous sodium carbonate and extracted with ether. The aqueous phase was acidified to pH 2.5 with dilute hydrochloric acid and extracted with ethyl acetate. The extract was concentrated in vacuo and the residue recrystallized from toluene to give methyl carboxymethyldithiocarbamate.

A mixture of 16.5 g. (0.1 mol.) of methyl carboxymethyldithiocarbamate and 14.3 g. (0.22 mol.) of sodium azide in 150 ml. of water was heated at 56° for 12 hours. The reaction mixture was extracted with ether, then acidified to pH 1.5 with dilute hydrochloric acid and extracted with ethyl acetate. The extract was dried(MgS04)and evaporated to dryness to give 1 - carboxymethyltetrazole5 - thiol, m.p. 178-179°. 1-Carboxymethyltetrazole-5-thiol was also prepared by refluxing a mixture of 45.95 g. (0.316 mol.) of ethyl isothiocyanatoacetate and 30.8 g. (0.475 mol.) .of sodium azide in 500 ml. of water for 2,75 hours. Ethyl acetate (400 ml.) was added to the cooled reaction mixture and it was acidified to pH 1.9 with 3N hydrochloric acid. The layers were separated, the aqueous phase was extracted three times with ethyl acetate and the combined extracts were dried (MgSO^) and evaporated to dryness to give a resiude which was chromatographed on silica gel with 17:3:2 chloroform-isopropanol-formic acid to give the tetrazole-thiol, A mixture of 2.94 g. (10 mmol.) of 7-amino-cephalosporanic acid sodium salt, -17961 .40 g. (15 mmol.) of 1-carboxymethyltetrazole-5-thiol and 2.52 g. (30 mmol.) of jdium bicarbonate in 40 ml. of water was heated at 70° for four hours. The ’action mixture was cooled (ice bath), acidified to pH 1.8 with 3N hydrochloric :id and evaporated to dryness 'in vacuole give 7 - amino -3-(1- carboxyithyltetrazol-5-ylthiomethyl)-3-cephem-4-carboxyl'ic acid.

To a solution of 1.86 g. (5 mmol.) of 7-amino-3-(l-carboxymethyltetrazol~ •ylthiomethyl)-3-cephem-4-carboxylic acid and 1.68 g. (0.02 mol.) of sodium icarbonate in 60 ml. of water and 50 ml. of acetone at -15° was added a solution : 0.80 g. (5 mmol.) of 2 - thiophene-acetyl chloride in 50 ml. of acetone. The faction mixture was stirred and the temperature maintained below -10° during Idition. The mixture was stirred for 3.5 hours, then the acetone was removed in rcwoand the aqueous residue was extracted with ethyl acetate. Ethyl acetate is added to the aqueous phase and it was acidified to pH 1.5 by addition of 3N 'drochloric acid. The layers were separated and the aqueous phase was extracted th ethyl acetate. The extract was dried (MgSO^) and evaporated to dryness to ve a residue, which was chromatographed on silica with 8:2:1 chloroform-isoopanol- acetic acid as eluant. The product was dissolved in ethyl acetate and •iturated with hexane to give the title compound. 7H16N6°6S3· 0,25 C4H8°2 lculated: 41.69% C; '3.49% H; 16.20% N und: ’ 41.51% C; 3.54% H; 15.74% N The title compound is dissolved in methanol and the methanol solution is eated with O.196N sodium methoxide in methanol. The methanol is removed in mo and the residue is dissolved in a minimum amount of water to which isoopanol is added to give 7-(2-thienylacetamido)-3-(l-carboxymethyltetrazolylthiomethyl)-3-cephem-4-carboxylic acid sodium salt.

EXAMPLE 13, (2-Thi enylacetami do)-3-(1-M-methylcarbamoylmethyltetrazol-5-ylthi omethyl)-3cephem-4-carboxyTic acid.

A solution of 7.2 g. (44 mmol.) of 1,1-carbonyl di imidazole in 110 ml. of dry trahydrofuran and 20 ml. of dimethyl formamide was added to a solution of 7.0 g 3.8 mmol.) of 1-carboxymethyltetrazole-5-thiol in 110 ml. of dry tetrahydrofuran -18and 20 ml. of dimethylformamide. Tetrahydrofuran saturated with methylamine was added and the reaction mixture was stirred at 25° for 12 hours. The mixture was evaporated to dryness in vacuo the residue was diluted with 200 ml. of water and the resulting solution was adjusted to pH 2-3 by addition of 3N hydrochloric acid. The aqueous solution was extracted with ethyl acetate and the extract was dried (MgSO^) and evaporated to dryness. Ethyl acetate (15 ml.) and ether (10 ml.) were added to the residue and it was cooled to include crystallisation of 1 - N methylcarbamoylmethyltetrazole-5-thiol, m.p. 137-140°.

Reaction of l-N-methylcarbamoylmethyltetrazole-5-thiol-j 7-aminocephalosporanic acid sodium salt and sodium bicarbonate as described in the procedure of Example 12 gives 7 - amino - 3 - (1 - N - methylcarbamoylmethyltetrazol - 5 ylthiomethyl)-3-cephem-4-carboxylic acid.

Substitution of 7-amino - 3 - (1 - N - methyl carbamoylmethyltetrazol - 5 ylthiomethyl)-3-cephem-4-carboxylic acid in the procedure of Example 12 for 7 amino -3-(1- carboxymethy1tetrazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid while maintaining the pH at 7.6-7.8 throughout the reaction by addition of solid sodium bicarbonate gives the title compound.

EXAMPLE 14. 7-(2-Thienylacetami do)-3-(1-N,N-dimethylcarbamoylmethyltetrazol-5-y1thiomethyl)3-cephem-4-carboxylic acid.

To a solution of 5.42 g. (33.8 mmol.) of l-carboxymethyltetrazole-5-thiol in 75 ml. of dry tetrahydrofuran and 20 ml. of dry dimethylformamide was slowly added a solution of 5.49 g. (33.9 mmol.) of 1,1 - carbonyl-diimidazole in 95 ml. of dry dimethylformamide. The reaction mixture was stirred for 35 minutes, then 250 ml. of tetrahydrofuran saturated with dimethyl amine was added to the suspension and it was stirred at 25° for 12 hours. The mixture was concentrated to about 200 ml. and tetrahydrofuran and ether were added. The precipitate was collected by filtration and dissolved in 170 ml. of water. The aqueous solution was acidified to pH 2.0 by addition of 6N sulfuric acid and extracted with ethyl acetate. The ethyl acetate solution was evaporated to dryness and the residue was triturated with ether to give l-N,N-dimethy1carbamoylmethyltetrazole-5-thiol, -19ι S 1 i.p. 190-200° (dec.).

Reaction of 1 - N,N - dimethylcarbanoylmeehyltetrazole-S-thiol with 7 - amino ;ephalsporanic acid sodium salt as described in Example 13 followed by reaction if the 7-amino-3- (1- N,N - dimethyl carbamoyl-methyl tetrazol - 5 - ylthiomethyl )i-cephem -4- carboxylic acid thus formed with 2-thiophene-acethyl chloride as escribed in Example 12 gives the title compound.

EXAMPLE 15. 7-(2-Thienylacetamido)-3-(l-carbamoylmethy1tetrazol-5-ylthiomethyl )-3cephem-4-carboxylic acid. 1- Carboxymethyltetrazole - 5 - thiol and 1,1 - carbonyl di imidazole were eacted as described in Example 13. To the reaction mixture was added tetraydrofuran saturated with dry ammonia gas. The resulting suspension was stirred or 2.5 hours and the solid which formed was collected by filtration, washed with etrahydrofuran and dissolved in methanol. Amberlite IR-120 ion-exchange resin 50 g.) was added a,nd the suspension was stirred for 15 minutes. The resin was hen removed and washed with absolute methanol. The methanol solution was vaporated to dryness to give 1-carbamoylmethyl tetrazole -5-thiol, m.p. 200° dec.). l-Carbamylmethyltetrazole-5-thiol is reacted with 7 - aminocephalosporanic cid sodium salt to give 7 - amino -3-(1- carbamoymethyltetrazol -5- ylthioethyl) -3- cephem -4- carboxylic acid, which upon reaction with 2 - thiophenecetyl chloride, as described in Example 12, gives the title compound, EXAMPLE 16. 7-(2-Thienylacetamido)-3- l-(2-carboxyethylJtetrazol-5-ylthiomethyl -3cephem-4-carboxy1i c.aci d. 3-Alanine (17.8 g., 0.2 mol.) was added to a solution of 22.4 g. (0.4 mol.) f potassium hydroxide in 500 ml. of water at 25°. Carbon disulfide (12.2 ml., .2 mol.) was added and the reaction mixture was refluxed for three hours, le mixture was cooled, 28.4 g (0.2 mol.) of methyl iodide and 500 ml. of thanol were added and the resulting mixture was stirred for 30 minutes. The -ecipitate was collected by filtration, the filtrate was concentrated and the -2042961 aqueous residue was combined with the solid material and brought to pH 8.5-9 by addition of 10% aqueous sodium hydroxide. The resulting suspension was extracted with ethyl acetate and the extract discarded. Ethyl acetate was added to the aqueous phase which was then acidified to pH 1.5 with 6N hydrochloric acid. The layers were separated and the aqueous phase was extracted with ethyl acetate. The ethyl acetate extracts were combined, dried (MgSO^) and evaporated to dryness to give methyl Z-carboxyethyldithiocarbamate.

To a mixture of 25.37 g (0.143 mol.) of methyl 2-carboxyethyldi thiocarbamate and 5.5 g (0.143 mol) of sodium hydroxide in 210 ml. of water was added 9.25 g (0.143 mol.) of sodium azide. The reaction mixture was refluxed for one hour and then cooled, 100ml. of ether was added and the mixture was acidified to pH 1.7. The layers were separated, the aqueous phase was extracted with ether and the combined extracts were dried (MgSO^) and evaporated to dryness to give a residue which was recrystallized from acetone-chloroform to give 1-(215 carboxyethyl)tetrazole-5-thiol,m.p. 158-160°.

To a solution of 4.18 g. (0.01 mol) of 7 - (2 - thienylacetamido)eepha1osporanic acid sodium salt in 50 ml. of water was added 2.51 g. (0.015 mol.) of 1-(2- carboxyethyl)tetrazole -5- thiol and 1.26 g. (0.015 irol.) of sodium bicarbonate. Additional amounts of sodium bicarbonate were added to bring the pH of the reaction mixture to 7.0 and the mixture was heated at 69° for five hours. The reaction mixture was cooled, acidified to pH 6.0 by addition of dilute hydrochloric acid and extracted with ethyl acetate. The aqueous phase was acidified to pH 2.0, extracted with ethyl acetate and the extract was evaporated to dryness to give a residue which was chromatographed on silica with 90:10:3 chloroform-methanol-acetic acid as eluant to give the title compound.

The title compound was dissolved in ethyl acetate and triethylamine was added to form the corresponding triethylamine salt.

C24H33N7°6S3'C6H15N°·5 H2° Calculated: 46,43% C; 5.95% H; 15.79% N Found: 46.51% C; 5.83% H; 15.98% N -21EXAMPLE 17. 7-(2-Thi enylacetami do)—3- jj -(2-carbamoylethyl)tetrazol-5-ylthi omethyl] -3cephem-4-carboxylic acid.

When an equivalent amount of 1 - (2 - carboxyethyl) tetrazole -5- thiol /as substituted in the procedure of Example 15 for 1 - carboxymethyl tetrazole j -thiol, 1-(2- carbamoyl ethyl) tetrazole - 5 - thiol was obtanined, m.p. 181-182° (dec.).

A solution of 1 - (2 - carbamoylethyl)tetrazole - 5- thiol (10.4 g., 0.06 no!.) in 120 ml. of acetone was added to a warm (45°) solution of 10.9 g (0.04 nol.) of 7 - aminocephalosporanic acid in a mixture- of 220 ml. of water, 50 ml. )f acetone and 8.4 g. (0.01 mol.) of sodium bicarbonate. The temperature was -aised to 65° and the pH maintained at 7.4-7.6 by addition of aqueous sodium :arbonate solution. After three hours, the reaction mixture was cooled to 10° ind adjusted to pH 3.5 by addition of dilute hydrochloric acid. The resulting .olid was collected by filtration, washed with water and acetone and suspended in 95 ml. of 1.5N hydrochloric acid. The acid suspension was stirred at 25° For five hours, filtered and the pH cf the filtrate was adjusted to 3.5 by iddition of solid sodium bicarbonate. The solid was collected by filtration and /ashed with water and acetone to give 7 - amino - 3 - 0-(2-carbamoyl ethyl) tetrazol-5-ylthiomethylJ - 3 - cephem - 4 - carboxylic acid.

- Amino - 3 - 0 - (2 - carbamoylethyl(tetrazol -5- ylthiomethylj -3:ephem-4-carboxylic acid and 2-thiopheneacetyl chloride were reacted according te the procedure of Example 13 to give the title compound.

The title compound was dissolved in methanol and sodium methoxide solution vas addded until pH 6.9. Evaporation of the methanol gave the title compound is its sodium salt.

WwW3 : °·5 ¥ Calculated: 39.99% C; 3.54% H; 18.13% N :ound: 39.92% C; 3.48% H; 17.60% N 7-(2- Thienyl) -3-0-(2- carbamoyl ethyl )tetrazol-5-ylthiomethyl^J -3- cephem - 4 - carboxylic acid sodium salt is converted to the title -2242901 compound by methods previously described, EXAMPLE 18. 7-(1-Tetrazolylacetami do)-3-(1-carboxymethyltetrazol-5-ylthi omethy1 -3cephem-4-carboxylic acid. 7-(1- Tetrazolylacetamido)cephalosporanic acid (1.41 g., 3.7 mmol.) and 5 0.96 g. (6.0 mmol.) of 1 - carboxymethyltetrazole - 5 - thiol were added to a solution of 0.815 g. (9.7 mmol.) of sodium bicarbonate in 25 ml. of water. An additional 0.504 g. (6.0 mmol.) of sodium bicarbonate was added to bring the pH to 6.7 and the reaction mixture was heated at 53° for five hours while maintaining the pH at 6.6-6.8 by addition of acetic acid. The mixture was cooled, acidified to pH 1.9 by addition of 3N hydrochloric acid and extracted with ethyl acetate.

The extract was dried (NagSO^) and evaporated to dryness. The residue was dissolved in ethyl acetate and ether and hexane were added to precipitate the title compound.

C14N14N10°6S2‘°·6 C4H8°2 Calculated: 36.79% C; 3.53% H; 26.16% N Found: 36.28% C; 3.50% H; 25.85% N EXAMPLE 19. 7-(1-Tetrazolylacetami do)-3-β-(2-carboxyethyl)tetrazol-5-ylthi omethy Ij -3cephem-4-carboxylic acid.

When an equivalent amount of 1 - (2-carboxyethyl) - tetrazole - 5 - thiol was substituted in the procedure of Example 18 in place of 1 - carboxymethyltetrazole-5-thiol, the title compound was obtained.

C15H16N10°6S2 Calculated: 35.28% C; 3.24% H; 28.21% N Found: 35.80% C; 3.67% H; 24.16% N EXAMPLE 20, 7-(1-Tetrazolylacetamido)-3- {Ϊ-(3-carboxypropyl)tetrazol-5-ylthi omethyjj 3-cephem-4-carboxylic acid.

When an equivalent amount of 4 - aminobutyric acid was substituted in the -23procedure of Example 16 for 5 -alanine, methyl 3 - carboxypropyldithiocarbamate was prepared.

Reaction of methyl 3 - carboxypropyldithiocarbamate with sodium azide and sodium hydroxide as described in Example 16 gave 1-(3- carboxypropyl)tetrazole 5-thiol,m.p. 99-101°.

Substitution of an equivalent amount of 1 - (3 - carboxypropyl)tetrazole -5-thiol in the procedure of Example 18 in place of 1 - carboxymethyltetrazole -5- thiol gave the title compound.

C16H16W2-M2°·0·5 C3H8° Calculated: 33.87% C; 3.89% H; 22.57% N Found: 34.39% C; 3.46% H; 22.20% N EXAMPLE 21 7-(2-Thienylacetamido-3-£i-(3-carbanioylpropyl)tetrazol-5-ylthiomethyTj-3cephem-4-carboxylic acid.

When an equivalent amount of 1 - (3 - carboxypropyl) - tetrazole -5-thiol was substituted in the procudure of Example 15 for 1 - carboxymethyltetrazole - 5 - thiol, 1 - (3-carbamoylpropyl)tetrazole-5-thiol was obtained, m.p. 133136°.

Reaction of l-(3-carbamoylpropyl)tetrazole-5-thiol and 7-aminocephalosporanic acid as described in the procedure of Example 17 gives 7 - amino - 3 l-(3-carbamoylpropyl)tetrazol-5-ylthiomethyl -3-cephem-4-carboxylic acid.

- Amino -3- 0 - (3 - carbamoyl propyl)tetrazol -5- ylthiomethyl] -3cephem-4-carboxylic acid and 2-thiophene-acetyl chloride are reacted according to the procedure of Example 13 to give the title compound.

EXAMPLE 22. 7-(1-Tetrazolylacetami do)-3- jj -(5-carboxypentyl)tetrazol-5ylthiomethylj -3-cephem-4-carboxylic acid.

Substitution of an equivalent amount of 6-amino-caproic acid in the procedure of Example 16 forg -alanine gave methyl 5 - carboxypentyldithiocarbamate.

Reaction of methyl 5 - carboxypentyl di thiocarbamate with sodium azide and -2442961 sodium hydroxide as described in Example 16 gave 1 - (5-earboxypentyl)tetrazole· 5-thiol, m.p. 100-100.5°.

Substitution of an equivalent amount of 1 - (5 - carboxypentyl)tetrazole 5- thiol in the procedure of Example 18 in place of 1 - carboxymethyltetrazole -5-thiol gave the title compound.

C18H22N10°6S2·0·33 CH4^ Calculated: 40.09% C; 4.28% H; 25.50% N Found: 40.29% C; 4.18% H; 25.78% N EXAMPLE 23. 7-(1-T etrazoly 1 acetami do) -3- Q-( 5-carbamoyl pentyl) tetrazol -5-yl thi omethylj 3-cephem-4-carboxylic acid. 1-(5- Carboxypentyl)tetrazole - 5 - thiol (6.0 g., 28 mmol.) was slowly dissolved in 20 ml. of thionyl chloride and the mixture was stirred at 25° for 1.5 hours. Evaporation of the reaction mixture to dryness gave a residue which was dissolved in 30 ml. of tetrahydrofuran. The tetrahydrofuran solution was added to a cold mixture of 60 ml. of ammonium hydroxide and 30 ml. of tetrahydrofuran and the resulting mixture was stirred at 25° for two days. The mixture was extracted with ethyl acetate. The aqueous phase was acidified to pH 1 by addition of 6N hydrochloric acid to precipitate 1-(5-carbamoylpentyl)~ tetrazole - 5 - thiol, m.p. 155-157°.

Reaction of 7-(l-tetrazolylacetamido)cephalosporanic acid, l-(5-carbamoylpentyl)tetrazole - 5 - thiol sodium salt prepared from 1 - (5- carbamoyl pentyl) tetrazole -5- thiol as described in Example 1, and sodium bicarbonate according to the procedure of Example 1, gives the title compound.

EXAMPLE 24. 7-(2-Thi enylacetami do) -3-0 - (10-carbamoyldecyl)tetrazol-5-ylthi omethylj-3cephetn-4-carboxylic acid. 1-(10-Carbamoyldecyl)tetrazole - 5 - thiol was prepared from l-(10-carboxydecyl)tetrazole - 5 - thiol by the procedure described in Example 15, m.p. 112-114°. -25>961 To a solution of 0.084 g. (1.0 mmol.) of sodium bicarbonate in 11 ml. of water was added 0.285 g. (1.0 mmol.) of l-(10-carbamoyldecyl)tetrazole-5-thiol. The reaction mixture was heated to ca. 65°, 0.250 g. (0.6 mmol.) of 7 — (2 thienyl-acetamido)cehpalosporanic acid sodium salt was added and the heating was continued for 5.5 hours. The reaction mixture was chromatographed on Amberlite XAD-4 resin (a cross-linked polystyrene hydrophobic adsorbent resin with average pore diameter 50 angstroms; (Amberlite is a Registered Trade Mark) with water as the eluant. The product-containing fractions were evaporated to dryness and lyophized and the residue was chromatographed on silica with 9:1:0.5 chloroform-isopropanol formic acid as eluant to give the title compound.

The title compound was converted to the corresponding sodium salt as previously described. C26H34N705S3‘Na·0·5 H2° Calculated: 47.79% C; 5.36% H; 15 Found: 48.17% C; 5.37% H; 14 EXAMPLE 7-(1 -Tetrazolyl acetanii do)-3- β - (10-carboxydecyl) tetrazol-5-yl thi omethylj -3cephem-4-carboxylic acid.

A suspension of 56 g. (1.0 mol.) of potassium hydroxide and 100 g. (0.5 mol.) of 11 - aminoundecanoic acid in 170 ml. of water stirred for 30 minutes at 25°, then 40 g. (0.52 mol.) of carbon disulfide and 80 ml. of ethanol were added and the reaction mixture was stirred at 25° for 12 hours. The mixture was refluxed gently for two hours ahd cooled. Methyl iodide (71 g., 0.3 mol.) and 130 ml. of ethanol were added to the mixture and it was stirred at 25° for 12 hours. The mixture was evaporated to remove the ethanol and the solid residue was collected by filtration to give methyl 10-carboxydecyldithiocarbamate potassium salt.

Methyl 10-carboxydecyldithiocarbamate (28 g., 0.096 mol.), obtained by acidifying an aqueous solution of the potassium salt to pH 1.5 with 6N hydrochloric acid, extracting the mixture with ethyl acetate, and drying and evaporating the ethyl acetate extracts, was reacted with 6.5 g. (0.1 mol.) of -2642SC1 sodium azide according to the procedure described in Example 16. Acidification upon work-up gave 1 - (10 - carboxydecyl)tetrazole-5-thiol as a white prepcipitate, m.p. 95-98°.

I-(IO-Carboxydecyl)tetrazole-5-thiol, 7-(1-tetrazolylacetamido)cephalosporanic acid sodium salt and sodium bicarbonate were reacted as described in Example 24 to give the title compound.

EXAMPLE 26. 7-(1-Tetrazolylacetamido)-3-fl-(2-carboxy-l-methylethyl)-tetrazol-5-ylthiomethylj -3-cephem-4-carBoxylic acid.

Substitution of an equivalent amount of 3-aminobutyric acid in the procedure of Example 16 fore-alanine gave methyl (2-carboxy-l-methylethyl) di thiocarbamate.

Treatment of methyl (2-carboxy - 1 - methyl ethyl) - dithiocarbamate with sodium azide also as described in Example 16 gave 1-(2- carboxy -1-methylethyl)tetrazole-5-thio1,m.p. 169-172°. 7-(1 - Tetrazolylacetamido)cephalosporanic acid and 1-(2- carboxy - 1 methyl ethyl)tetrazole -5 - thiol are reacted in the presence of excess sodium bicarbonate as described in Example 16 to give the title compound.

EXAMPLE 27.

When an equivalent amount of an amino acid listed below: alanine 2-aminobutyric acid 2-aminovaleric acid 2-aminohexanoic acid is used in the procedure of Example 16 in place of β-alanine and the resulting di thiocarbamates are treated with sodium azide as described therein, the following substituted tetrazole-thiols are obtained: 1-(1-carboxyethyl)tetrazole-5-thi ol 1-(1-carboxypropyl)tetrazole-5-thi ol 1- (1-carboxybutyl)tetrazole-5-thiol 1-(1-carboxypentyl)tetrazole-5-thi ol -27Reaction of a tetrazol e-thi ol listed above with 7-(1 - tetrazolylacetaiiido)-cephalosporanic acid as described hereinabove gives the following :ompounds of this invention: 7-(1 - tetrazolylacetamido) - 3 - 0 - (1 - carboxyethyl) -tetrazol - 5- ylthiomethylj -3-cephem-4-carboxylic acid 7-(1 - tetrazolyl acetami do) -3-0-(1- carboxypropyl )-tetrazol - 5- ylthiomethylj -3-cephem-4-carboxylic acid 7-(1 - tetrazolyl acetami do) -3-0-(1- carboxybutyl )-tetrazol - 5- ylthiomethylj -3-cephem-4-carboxylic acid 7-(1 - tetrazolylacetamido) -3-0-(1- carboxypentyl) -tetrazol - 5- ylthiomethylj -3-cephem-4-carboxylic acid.

Likewise, reaction of a substituted tetrazolethiol listed above with 7-(2fchiertylacetamido)cephalosporanic acid according to the procedures described lerein gives the corresponding 7-(2- thienyl acetamido) - 3 - (1 - carboxyilkyltetrazol - 5- ylthiomethyl)-3-cephem-4-carboxylic acids.

EXAMPLE 28.

The following compounds were prepare^ according to procedures described lereinabove: 7-(2- thienyl acetami do) -3-0-(3- carboxypropyl) tetrazol - 5- ylthiomethyl] -3-cephem-4-carboxylic acid Ί9Η18Ν653θ6·2Ν3·2Η2θ Calculated: 37.75% C; 3.67% H; 13.89% N -ound: 38.25% C; 3.61% H; 13.49% N - (2 - thienylacetamido -3-0-(5- carboxypentyl) tetrazol - 5- ylthiomethylj -3-cephem-4-carboxylic acid :21H22N6°6S3‘2Na·0·75 H2° Calculated: 41.34% C; 3.88% H; 13.77% N 7ound: 41.30% C; 3.76% H; 13.58% N EXAMPLE 29.

An injectable pharmaceutical composition is formed by adding sterile water Dr sterile saline solution (2 ml.) to 500 mg of 7 - (2 - thienylacetamido) - 3 -2842SG1 Π - (2-carbamoylethyl)tetrazol - 5 - ylthiomethylJ -3-cephem-4-carboxylic acid, sodium salt.

Pharmaceutical compositions of the other antibacterial compounds disclosed above may be formulated in a similar manner.

Claims (14)

1. A cephalosporin compound of the formula in which is thienyl or tetrazolyl; and Het is selected from: H -»n • ·

2. In which each individual R is hydrogen or lower alkyl, n is zero or one to ten, m is one to ten and R is hydroxy, amino, lower ilkyl- amino or di(lower alkyl)amino, or a non-toxic pharmaceutically acceptable :alt thereof. I. A compound according to claim 1 in which Het is substituted tetrazolyl. I. A compound according to claim 2 in which m is from 1 to S ο A compound according to any one of claims 1 to

3. In which R is hydrogen. o >. A compound according to any one of claims 1 to

4. In which R is hydroxy •r amino, 7-(2 - Thi enyl acetami do) -3- 0- (10 - carbamoyl decyl) - tetrazol -51thi omethy l^-3-cephem-4-carboxylic acid. -304S9G1 7. 7-(1- Tetrazolylacetamido) -3-(5- carboxymethyl - 1,2,4 - triazol 3-ylthiomethyl)-3-cephem-4-carboxylic acid. 8. 7-(2- Thienylacetamido) -3-(1- carboxymethyltetrazol - 5 - ylthiomethyl)-3-cephem-4-carboxylic acid.

5. 9. 7-(2- Thienylacetamido) - 3 - |l - (2 - carbamoyl ethyl) - tetrazol - 5ylthiomethylj -3-cephem-4-carboxylic acid.

6. 10. 7-(1- Tetrazolylacetamido) -3-(1- carboxymethyl tetrazol - 5 - yl thiomethyl )-3-cephem-4-carboxy1ic acid.

7. 11. 7-(2- Thienylacetamido) -3- £l-(2-carboxyethyl)tetrazol-5-ylthiomethylj 10 -3-cephem-4-carboxylic acid.

8. 12. 7-(1- Tetrazolylactamido)-3- £l - (2-carboxyethyl)-tetrazol - 5-ylthiomethyl] -3-cephem-4-carboxylic acid.

9. 13. A process for preparing a compound according to Claim 1 which comprises acylating a compound of the formula . 4 in which Het is as defined in Claim 1 and R is hydrogen or an ester-forming protecting group, with an activated thienyl- or tetrazolyl- acetic acid, followed, if necessary, by removal of the protecting group.

10. 14. A process for preparing a compound according to Claim 1 which comprises 20 acylating 7 - aminocephalosporanic acid with a thienyl- or tetrazolyl- acetic acid RkH 2 C00H and then displacing the 3-acetoxy group with the required substituted triazole- or tetrazole- thiol HSHet.

11. 15. A process for the preparation of a compound according to Claim 1 substantially as hereinbefore described in any one of Examples 1 to 27. 25

12. 16. A compound according to Claim 1 whenever prepared by a process according to -31asset to any one of Claims 13, 14 and 15.

13. 17. A pharmaceutical composition comprising a compound according to any one of Claims 1 to 12 and 16 and a pharmaceutically acceptable carrier.

14. 18. A method of treating or preventing bacterial infections in non-human mammals which comprises administering a compound according to any one of Claims 1 to 12 and 16 in a non-toxic amount sufficient to treat or prevent said infection.