Novel cephalosporins having various acyl substituents at the 7-position and a carboxymethylthio substituted triazolylthiomethyl group at the 3-position of the cephem nucleus are prepared. These compounds have antibacterial activity.

This invention relates to a new series of cephalosporin compounds having 
antibacterial activity and to intermediates useful for preparing them. The 
structures of the new compounds are characterized by having at the 
3-position a carboxymethylthio substituted triazole group. 
Exemplary of the compounds of this invention are those represented by the 
following structural formula: 
##STR1## 
in which R represents a pharmaceutically acceptable acyl group know to be 
of utility as a substituent on the 7-amino group in the structures of 
known or prior art cephalosporins or on the 6-amino group in the 
structures of known or prior art penicillins. 
Representative acyl substituents are: 
##STR2## 
wherein: X is thienyl, furyl, phenyl or phenyl monosubstituted with 
hydroxy, hydroxymethyl, formamido or ureido; 
A is NH.sub.2, OH, COOH, SO.sub.3 H, formyloxy or, when the 
.alpha.-C-hydrogen is absent, methoxyimino; 
Y is cyano, sydnone, pyridone, thienyl, o-aminomethylphenyl, phenyl or 
tetrazolyl; 
Z is methyl, trifluoromethyl, trifluoroethyl, pyridyl or cyanomethyl; and 
m is 0 to 2; 
R' is hydrogen or an alkali metal salt such as sodium or potassium. 
Each of the three partial structures above represent subgeneric groups of 
compounds covered by this invention. 
Representative 7-acylamino substituents of the compounds of Formula 1 are 
listed below: 
.alpha.-hydroxyphenylacetamido 
.alpha.-aminophenylacetamido 
.alpha.-amino-4-hydroxyphenylacetamido 
Trifluoromethylthioacetamido 
2,2,2-trifluoroethylsulfinylacetamido 
2,2,2-trifluoroethylthioacetamido 
Cyanoacetamido 
.alpha.-carboxythienylacetamido 
.alpha.-carboxyphenylacetamido 
.alpha.-sulfophenylacetamido 
Methylsulfonylacetamido 
Cyanomethylthioacetamido 
3-sydnoneacetamido 
1-tetrazolylacetamido 
2-thienylacetamido 
.alpha.(Z)-(methoxyimino)-2-furanacetamido 
4-pyridylthioacetamido 
O-aminomethylphenylacetamido 
Others together with N-acrylation procedures may be found in Cephalosporins 
and Penicillins, Flynn, Academic Press, 1972; U.S. Pat. Nos. 2,721,196 and 
3,953,424; Belgian Pat. No. 832,725; German Pat. Nos. 2,127,285 and 
2,406,165. 
It will be recognized that the 4-carboxylic acid group of the compounds of 
Formula 1 may be readily esterified by methods well known to the art. 
These esters include, for example, simple alkyl and aryl esters as well as 
esters which are easily cleaved, within the body, to the parent acid such 
as indanyl, pivaloyloxymethyl, acetoxymethyl, propionyloxymethyl, 
glycyloxymethyl, phenylglycyloxymethyl and thienylglycyloxymethyl esters 
and others. Of course, when A is COOH, this group may be similarly 
esterfied. All such ester derivatives are included within the scope of 
this invention. 
Also covered in this invention are the pharmaceutically acceptable, 
nontoxic derivatives of the compounds of Formula 1 from which they derive 
utility: the salts, as stated above easily split ester or ether 
derivatives of either a carboxy or hydroxy function, amide derivatives at 
an amino group contained in a 7-phenylglycylamino group, for example, the 
furyl-, pyranyl-, oxolanyl- or oxiranylcarbonyl amides (i.e. Belgian Pat. 
No. 835,295), the solvates such as hydrates, glycolates or alcoholates. As 
examples of these, one skilled in the art would be able to prepare and use 
the alkali metal salts such as the sodium or potassium salts (for example 
using sodium or potassium 2-ethyl hexanoate), ammonium salts, organic 
amine salts such as those with procaine or dibenzylethylenediamine. 
Other known cephalosporin modifications can be made by known synthetic 
procedures such as introduction of an .alpha.-methoxy group at position 7, 
preferably at the stage of the 7-aminocephalosporanic acid reactants 
disclosed below (IV), prior to N-acrylation. Optical isomers are also 
possible such as with the mandeloyl or phenylglycyl substituents at 7. The 
D-forms of these subgeneric groups are preferred. 
The compounds of this invention are most conveniently prepared by a 
displacement of the acetoxy group of a known 7-acylaminocephalosporanic 
acid (II) by [(4,5-dihydro-5-thioxo-1H-1,2,4-triazol-3-yl)thio]acetic acid 
(III). Alternatively a similar displacement with the above acetic acid can 
be run on 7-aminocephalosporanic acid to give 
7-amino-3-[[3-(carboxymethyl)thio-1H-1,2,4-triazol-5-yl]thiomethyl]-3-ceph 
em-4-carboxylic acid (IV) which may then be N-acylated as known to the art 
as described above. Suitable protective groups may be used in either 
method as is known to the art (see "Protective Groups in Organic 
Chemistry", J. F. W. McOmie, Plenum Press, 1973, Chapters 2 and 3 for use 
of amino, carboxy, sulfo or hydroxyl protective groups). 
For example, the t-butyl (for COOH) or t-butoxycarbonyl (for NH.sub.2) 
groups are easily removed by treatment with trifluoroacetic acid. 
The carboxymethylthio substituted triazole, which may exist in several 
tautomeric forms, and is here expressed by Formula III, is a new compound 
and is part of this ivnention. 
##STR3## 
The invention also includes the alkali metal and ammonium salts of the 
compound of Formula III. 
The compounds of Formula I have antibacterial activity against both Gram 
positive and Gram negative bacteria with minimum inhibitory concentrations 
(MIC's) in vitro from 0.2 to greater than 200 .mu.g/ml. Test results for 
7-D-mandelamido-3-[[3-(carboxymethyl)thio-1H-1,2,4-triazol-5-yl]thiomethyl 
]-3-cephem-4-carboxylic acid, disodium salt, hydrate (A) are: 
______________________________________ 
Cepha- Cefa- 
A lothin zolin 
______________________________________ 
S. aureus HH 127 1.6 0.4 0.4 
S. aureus SK 23390 
0.8 0.2 0.4 
S. aureus villaluz SK 70390 
&gt;200 50 200 
Strep. faecalis HH 34358 
100 12.5 6.3 
E. coli SK 12140 0.8 3.1 1.6 
E. coli HH 33779 0.8 6.3 1.6 
Kleb. pneumo. SK 4200 
0.4 3.1 1.6 
Kleb. pneumo. SK 1200 
0.2 1.6 0.8 
Salmonella ATCC 12176 
0.8 1.6 0.8 
Pseudo. aeru. HH 63 
&gt;200 200 &gt;200 
Serratia marc. ATCC 13880 
12.5 &gt;200 &gt;200 
Proteus morgani 179 
1.6 &gt;200 200 
Entero. aerog. ATCC 13048 
1.6 12.5 1.6 
Entero. cloacae HH 31254 
0.8 6.3 0.8 
______________________________________ 
Compound A gave an ED.sub.50 in mice of 1.56 against E. coli as well as 
1.02 mg/kg against Kleb. pneumo. (s.c.). 
These results are superior to those for a related compound, 
7-D-mandelamido-3-(2-carboxymethylthio-1,3,4-thiadiazol-5-yl-thiomethyl)-3 
-cephem-4-carboxylic acid, sodium salt hydrate which gave an ED.sub.50 
against E. coli of 6.4 and as well as 4.4 mg/kg against Kleb. pneumo. 
Pharmaceutical compositions having antibacterial activity which comprise a 
pharmaceutical carrier containing an active but nontoxic quantity of a 
compound of Formula 1 as well as methods of combatting bacterial 
infections by administering such a composition to an infected animal or 
human host in a nontoxic amount sufficient to combat such infections are 
also objects of this invention. The administration may be orally or by 
parenteral injection such as subcutaneously, intramuscularly or 
intravenously. The injection of suitably prepared sterile solutions or 
suspensions containing an effective, nontoxic amount of the new 
cephalosporin compound is the preferred route of administration. 
The compounds of Formula 1 are formulated and administered in the same 
manner as other prior art cephalosporins such as cephazolin of 
cephalothin. The dosage regimen comprises administration, preferably by 
injection, of an active but nontoxic quantity of a compound of Formula 1 
selected from the dosage unit range of from about 250 mg. to 600 mg. with 
the total daily dosage regimen being from about 750 mg. to 6 g. The 
precise dosages are dependent upon the age and weight of the subject and 
on the susceptibility of the infection being treated to each individual. 
These can be determined by those skilled in the art based on the data 
disclosed herein compared with that available to the art attained with the 
known cephalosporins outlined herebefore. 
The following examples illustrate the invention but are not to be construed 
as limiting the scope thereof. Temperatures are in degrees Centigrade 
(.degree. C.) unless otherwise stated.

EXAMPLE 1 
To a suspension of 5.48 g. (40 mmol) of 1,2,4-triazolidine-3,5-dithione, 
monohydrazine salt in 80 ml. of tetrahydrofuran and 80 ml. of 
dimethylformamide was added a solution of 6.7 (40 mmol) of ethyl 
bromoacetate in 20 ml. of tetrahydrofuran. The mixture was stirred at room 
temperature for 11/2 hours, and then at 50.degree. C. for 1/2 hour. The 
solution was filtered and the filtrate was concentrated to 80 ml., diluted 
with 250 ml. of water and extracted with diethyl ether. The extract was 
dried (MgSO.sub.4) an evaporated to dryness to give a residue which was 
crystallized from methanol and water to give 5.76 g. (65% yield) of ethyl 
[(4,5-dihydro-5-thioxo-1H-1,2,4-triazol-3-yl)thio]acetate. mp 
134.degree.-6.degree. C. 
A solution of 2.19 g. (10 mmol) of ethyl 
[(4,5-dihydro-5-thioxo-1H-1,2,4-triazol-3-yl)thio]acetate in 50 ml. of 5% 
sodium hydroxide was heated at reflux for 1 hour. After thorough cooling, 
the mixture was filtered, and the filtrate was washed with ethyl acetate. 
The aqueous layer was separated, acidified to pH 1 and extracted with 
ethyl acetate. The extract was evaporated in vacuo to dryness. The residue 
was crystallized from chloroform to give 1.43 g. (75% yield) of 
[(4,5-dihydro-5-thioxo-1H-1,2,4-triazol-3-yl)thio]acetic acid. 
To a solution of 1.16 g. (13.8 mmol) of sodium bicarbonate in 30 ml. of 
water was added 1.32 g. (6.9 mmol) of 
[(4,5-dihydro-5-thioxo-1H-1,2,4-triazol-3-yl)thio]acetic acid. After 
CO.sub.2 gas evolution had ceased, 2.12 g. (5 mmol) of 
7-mandelamido-cephalosporanic acid sodium salt was added to the solution. 
The mixture was heated at 80.degree. C. for 3.5 hours. After cooling, the 
solution was filtered. The filtrate was applied to an XAD-7 (200 ml.) 
resin column, eluting with water. The fractions containing product by thin 
layer chromatography were pooled and evaporated to dryness. The residue 
was triturated with absolute ethanol and filtered. The filtrate was 
diluted with isopropanol, and the solid formed was filtered, air-dried, 
dissolved in de-ionized water and lyophilized to give 1.02 g. (15.6% 
yield) of 
7-D-mandelamido-3-[[3-(carboxymethyl)thio-1H-1,2,4-thiazol-5-yl]thiomethyl 
]-3-cephem-4-carboxylic acid, disodium salt hydrate, mp 
220.degree.-230.degree. C. dec. Anal. calculated for C.sub.20 H.sub.17 
N.sub.5 O.sub.7 S.sub.3 Na.sub.2 . 4H.sub.2 O = C, 36.75; H, 3.85; N, 
10.71. Found: C, 36.47; H, 3.53; N, 10.11. IR-(NUJOL) = 5.65 .mu.. 
EXAMPLE 2 
An aqueous solution (100 ml.) of 4.27 g. (0.0096 mol) of 
7-[.alpha.(Z)-(methoxyimino)-2-furanacetamido]cephalosporanic acid sodium 
salt, 1.78 g. (0.0212 mol) of sodium bicarbonate and 2.02 g. (0.0106 mol) 
of [(4,5-dihydro-5-thioxo-1H-1,2,4-triazol-3-yl)thio]acetic acid is heated 
at 65.degree. C. for 6 hours during which time the pH is maintained at 
7.6-7.8 with dilute sodium bicarbonate. After cooling, the reaction 
mixture is purified on an XAD-7 column as described in Example 1 to give a 
lyophilized product, 
7-[.alpha.(Z)-(methoxyimino)-2-furanacetamido]-3-[[3-(carboxymethyl)thio-1 
H-1,2,4-triazol-5-yl]thiomethyl]-3-cephem-4-carboxylic acid, disodium salt. 
EXAMPLE 3 
A mixture of 5.22 g. (10.0 mmol) of 
7-(D-.alpha.-t-butoxycarbonylamino-4-hydroxyphenylacetamido)cephalosporani 
c acid and an excess (15.0 mmol) of 
[(4,5-dihydro-5-thioxo-1H-1,2,4-triazol-3-yl)thio]acetic acid in 75 ml. of 
pH 6.4 phosphate buffer solution is treated with sufficient sodium 
bicarbonate to give a pH of 6.4. The mixture is heated at 70.degree. for 3 
hours, cooled, acidified with dilute hydrochloric acid to pH 2 and 
extracted with ethyl acetate. Removal of the ethyl acetate in vacuo give 
the t-boc derivative of the desired compound. This derivative is stirred 
at 25.degree. C. with 25 ml. of trifluoroacetic acid and 25 ml. of 
1,3-dimethoxybenzene for 2 hours. The mixture is evaporated to dryness in 
vacuo, ethyl acetate is added to the residue and the precipitated salt is 
collected. This is dissolved in water and treated with Amberlite IR-45 
weakly basic ion-exchange resin. The solution is lyophilized to give 
7-(D-.alpha.-amino-4-hydroxyphenylacetamido)-3-[[3-(carboxymethyl)thio-1H- 
1,2,4-triazol-5-yl]thiomethyl]-3-cephem-4-carboxlic acid. Similar treatment 
of the t-boc derivatives of the 
7-DL-(.alpha.-aminophenylacetamido)cephalosporanic acid gives the 
corresponding 
7-DL-(.alpha.-aminophenylacetamido)-3-[[3-carboxymethyl)thio-1H-1,2,4-tria 
zol-5yl]thiomethyl]-3-cephem-4-carboxylic acid. 
EXAMPLE 4 
A mixture of an excess (12.2 mmol) of 
[(4,5-dihydro-5thioxo-1H-1,2,4-triazol-3-yl)thio]acetic acid, 32.5 mmol of 
sodium dicarbonate and 8.1 mmol of 
7-trifluoromethylthioacetamidocephalosporanic acid in 50 ml. of water is 
stirred at 70.degree. for 5 hours. The reaction mixture is cooled and 
applied to an XAD-2 column and eluted with water and then methanol. The 
product-containing effluent is evaporated to dryness to give a residue 
which is dissolved in a small amount of water and lyophilized to give 
7-trifluoromethylthioacetamido-3-[[3-(carboxymethyl)thio-1H-1,2,4-triazol- 
5-yl]thiomethyl]-3-cephem-4-carboxylic acid disodium salt. Substituting 
7-(2-thienylacetamido)-cephalosporanic acid gives 
7-(2-thienylacetamido)-3-[[3-(carboxymethyl)thio-1H-1,2,4-triazol-5-yl]thi 
omethyl]-3-cephem-4-carboxylic acid disodium salt. 
Stoichiometric quantities of cephalosporanic acids having the individual 
7-acylamino substituent listed hereabove may be substituted in Examples 
1-3 with variations which will be obvious to those skilled in this art. 
EXAMPLE 5 
An injectable pharmaceutical composition is formed by adding sterile saline 
solution (2 ml.) to 500 mg. of the product of Example 1. This material is 
injected parenterally four times daily to a human patient infected with 
susceptible bacteria. Other compounds of this invention may be similarly 
used.