Abstract: 7.alpha.-(Dimethylamidino)-3-cephem ester 1.alpha.-oxides represented by the formula ##STR1## wherein R is hydrogen or acetoxy and R.sub.1 is a carboxy protecting group, are prepared via DBU epimerization of the corresponding 7.beta.-isomer. When R is hydrogen the intermediates are useful in the preparation of the 7.beta.-acylamino-7.alpha.-methoxy-1-oxa-.beta.-lactam antibiotics, and when R is acetoxy the compounds are intermediates to 7.beta.-acylamino-7.alpha.-methoxy-3-exomethylenecepham compounds.

Abstract: 6-Epi penicillin .alpha.-sulfoxides represented by the formula ##STR1## wherein R is a carboxy protecting group, are useful for preparing antibiotic compounds and are prepared via epimerization with an alkali metal acetate of corresponding 6.beta.-epimer.

Abstract: 7-Amino-3-hydroxy-3-cephem esters react with a chlorinating agent, e.g. phosgene, thionyl chloride and preferably PCl.sub.3 -DMF to provide 7.beta.-[(dimethylaminomethylene)amino]-3-chloro-3-cephem esters which on reaction with a carboxylic acid, a percarboxylic acid, or a phenol, having a pH in water of about 2-5, afford 7.beta.-formamido-3-chloro-3-cephem esters, and corresponding 2-cephem esters. Percarboxylic acids provide 7.beta.-formamido-3-chloro-3-cephem ester 1-oxides. The 7-formamido derivatives provide the 7-amino-3-chloro-3-cephem ester on acid hydrolysis. The 7-amino-3-chloro esters are useful for preparing antibiotics.

Abstract: 7-Acylamido- and 7-amino-3-halo-3-cephem-4-carboxylic acids, esters and pharmaceutically-acceptable salts and esters thereof are new cephalosporin compounds provided by the reaction of a 7-acylamido-3-hydroxy-3-cephem-4-carboxylic acid ester or a 7-amino-3-hydroxy-3-cephem-4-carboxylic acid ester with an iodinating, fluorinating, chlorinating, or brominating reagent. For example, 7-amino-3-chloro-3-cephem-4-carboxylic acid and 7-phenoxyacetamido-3-chloro-3-cephem-4-carboxylic acid are provided. The 7-acylamido-3-halo cephalosporin acids and pharmaceutically acceptable salts and esters provided are valuable antibiotic compounds having desirable therapeutic properties.

Abstract: 7-Acylamido- and 7-amino-3-halo-3-cephem-4-carboxylic acids, esters and pharmaceutically-acceptable salts and esters thereof are new cephalosporin compounds provided by the reaction of a 7-acylamido-3-hydroxy-3-cephem-4-carboxylic acid ester or a 7-amino-3-hydroxy-3-cephem-4-carboxylic acid ester with an iodinating, fluorinating, chlorinating, or brominating reagent. For example, 7-amino-3-chloro-3-cephem-4-carboxylic acid and 7-phenoxyacetamido-3-chloro-3-cephem-4-carboxylic acid are provided. The 7-acylamido-3-halo cephalosporin acids and pharmaceutically acceptable salts and esters provided are valuable antibiotic compounds having desirable therapeutic properties.

Abstract: 7-Acylamido- and 7-amino-3-halo-3-cephem-4-carboxylic acids, esters and pharmaceutically-acceptable salts and esters thereof are new cephalosporin compounds provided by the reaction of a 7-acylamido-3-hydroxy-3-cephem-4-carboxylic acid ester or a 7-amino-3-hydroxy-3-cephem-4-carboxylic acid ester with an iodinating, fluorinating, chlorinating, or brominating reagent. For example, 7-amino-3-chloro-3-cephem-4-carboxylic acid and 7-phenoxyacetamido-3-chloro-3-cephem-4-carboxylic acid are provided. The 7-acylamido-3-halo cephalosporin acids and pharmaceutically acceptable salts and esters provided are valuable antibiotic compounds having desirable therapeutic properties.

Abstract: 7-Acylamido- and 7-amino-3-halo-3-cephem-4-carboxylic acids, esters and pharmaceutically-acceptable salts and esters thereof are new cephalosporin compounds provided by the reaction of a 7-acylamido-3-hydroxy-3-cephem-4-carboxylic acid ester or a 7-amino-3-hydroxy-3-cephem-4-carboxylic acid ester with an iodinating, fluorinating, chlorinating, or brominating reagent. For example, 7-amino-3-chloro-3-cephem-4-carboxylic acid and 7-phenoxyacetamido-3-chloro-3-cephem-4-carboxylic acid are provided. The 7-acylamido-3-halo cephalosporin acids and pharmaceutically acceptable salts and esters provided are valuable antibiotic compounds having desirable therapeutic properties.

Abstract: 7-Acylamido- and 7-amino-3-halo-3-cephem-4-carboxylic acids, esters and pharmaceutically-acceptable salts and esters thereof are new cephalosporin compounds provided by the reaction of a 7-acylamido-3-hydroxy-3-cephem-4-carboxylic acid ester or a 7-amino-3-hydroxy-3-cephem-4-carboxylic acid ester with an iodinating, fluorinating, chlorinating, or brominating reagent. For example, 7-amino-3-chloro-3-cephem-4-carboxylic acid and 7-phenoxyacetamido-3-chloro-3-cephem-4-carboxylic acid are provided. The 7-acylamido-3-halo cephalosporin acids and pharmaceutically acceptable salts and esters provided are valuable antibiotic compounds having desirable therapeutic properties.

Abstract: 3-Exomethylenecepham and 3-hydroxy-3-cephem sulfoxides represented by the formulas ##STR1## wherein R is an acyl group derived from a carboxylic acid and R.sub.1 is a carboxylic acid protecting group, are useful intermediates in the synthesis of 3-alkoxy-3-cephem, 3-chloro-3-cephem and 3-methyl-3-cephem antibiotic compounds.

Abstract: 7-Acylamino-3-methyl-3-cephem-4-carboxylic acids and esters are prepared via the reductive cleavage of a 3-thio substituted 2-cephem-4-carboxylic acid or ester with hydrogen and Raney nickel or zinc in formic acid and DMF to provide reduction product mixtures of the corresponding 7-substituted 3-methyl-2-cephem-4-acid or ester (I) and 3-exomethylenecepham-4-acid or ester (II). Reduction product mixtures are separable via chromatography and individual I and II are isomerized to 3-methyl-3-cephem antibiotics.

Abstract: 7-Acylamido-3-cephem-4-carboxylic acid antibiotics directly substituted in the 3-position of the cephem ring system with a sulfur atom bonded to a 5- or 6-membered heterocyclic ring, a lower alkyl group, or a phenyl or substituted phenyl group are prepared with the corresponding 3-halo-3-cephem esters. For example, p-nitrobenzyl 7-[2-(2-thienyl)acetamido]-3-chloro-3-cephem-4-carboxylate reacts with 1-methyl-1H-tetrazol-5-ylthiol to provide p-nitrobenzyl 7-[2-(2-thienyl)acetamido]-3-[(1-methyl-1H-tetrazol-5-yl)thio]-3-cephem-4- carboxylate. The p-nitrobenzyl ester group is removed by catalytic hydrogenolysis to provide the antibiotic carboxylic acid compound. Alternatively, the antibiotics are prepared by reacting a 3-alkylsulfonyloxy, or 3-arylsulfonyloxy-3-cephem, for example, 3-methanesulfonyloxy-3-cephem, or a 3-p-toluenesulfonyloxy-3-cephem with the heterocyclic thiol, the phenyl or substituted phenylthiol, or with the lower alkylthiol.

Abstract: 7-Acylamido- and 7-amino-3-halo-3-cephem-4-carboxylic acids, esters and pharmaceutically-acceptable salts and esters thereof are new cephalosporin compounds provided by the reaction of a 7-acylamido-3-hydroxy-3-cephem-4-carboxylic acid ester or a 7-amino-3-hydroxy-3-cephem-4-carboxylic acid ester with an iodinating, fluorinating, chlorinating, or brominating reagent. For example, 7-amino-3-chloro-3-cephem-4-carboxylic acid and 7-phenoxyacetamido-3-chloro-3-cephem-4-carboxylic acid are provided. The 7-acylamido-3-halo cephalosporin acids and pharmaceutically acceptable salts and esters provided are valuable antibiotic compounds having desirable therapeutic properties.

Abstract: 3-Methylenecepham-4-carboxylic acids and esters of the Formula I and 3-methyl-.DELTA..sup.3 -cephem-4-carboxylic acids and esters of the Formula II ##SPC1##where R is hydrogen or an organic acyl group and R.sub.1 is hydrogen, C.sub.1 -C.sub.4 alkyl a carboxylic acid protecting group or a pharmaceutically acceptable cation are prepared via the reductive displacement of a 3-substituted methyl cephalosporin of the Formula III ##SPC2##where R.sub.2 is an organic residue such that --SR.sub.2 constitutes a reductively displaceable moiety, and R and R.sub.1 have the same meanings as defined in Formulae I and II, reductive displacement being accomplished by catalytic hydrogenation or chemical reduction. The 3-methylene cepham compounds are isomerized in dimethylacetamide in the presence of a tertiary alkyl amine to provide 3-methyl-7-acylamido-.DELTA..sup.3 -cephem-4-carboxylic acids and esters.