Abstract: A method for preparing 2-amino-.beta.-lactams which are substituted by readily-removed protecting groups is provided. According to this invention, an acyl-2-amino-.beta.-lactam is further acylated with a different acyl group and is subsequently treated with base to provide a protected 2-amino .beta.-lactam with a more desirable protecting group.

Abstract: A method for preparing 2-amino-.beta.-lactams which are substituted by readily-removed protecting groups is provided. According to this invention, an acyl-2-amino-.beta.-lactam is further acylated with a different acyl group and is subsequently treated with base to provide a protected 2-amino .beta.-lactam with a more desirable protecting group.

Abstract: A method for preparing 2-amino-.beta.-lactams which are substituted by readily-removed protecting groups is provided. According to this invention, an acyl-2-amino-.beta.-lactam is further acylated with a different acyl group and is subsequently treated with base to provide a protected 2-amino .beta.-lactam with a more desirable protecting group.

Abstract: A method for preparing 2-amino-.beta.-lactams which are substituted by readily-removed protecting groups is provided. According to this invention, an acyl-2-amino-.beta.-lactam is further acylated with a different acyl group and is subsequently treated with base to provide a protected 2-amino .beta.-lactam with allyloxycarbonyl, t-butoxycarbonyl, naphthyloxycarbonyl, trichloroethyloxycarbonyl, p-nitrobenzyloxycarbonyl, benzhydryloxycarbonyl, p-methoxybenzyloxycarbonyl, or o-nitrobenzyloxycarbonyl.

Abstract: 3-(alkynylalkyloxy)cephalosporin antibiotics and the intermediates therefor are disclosed. Pharmaceutical compositions for the antibiotics are also disclosed.

Abstract: Fused 4,7-.beta.-lactam bicyclic antibacterials, namely 8-acylamino-4-anilino-9-oxo-6-thia-1,3-diazabicyclo[5.2.0]non-3-ene-2-carb oxylic acids, and the esters, salts and sulfoxides thereof, are provided. The compounds as esters are prepared by process comprising heating a 3-azido-3-cephem ester with aniline, a substituted aniline, or an N-(C.sub.1 -C.sub.3 alkyl) derivative thereof.

Abstract: 3-Azido-3-cephem esters are reacted with electron rich olefins, e.g., enamines and cyclic enol ethers, to provide C.sub.3 amidines and imidates having antibacterial activity in the free acid form. For example, 3-azido-3-cephem esters react with ethyl vinyl ether to provide 3-[1-(ethoxyethylidene)amino]-3-cephem esters. The latter are deesterified to provide the free acid antibacterials.

Abstract: N-ethylidene azetidinones are new antibiotic compounds. They are produced from the reaction of a Grignard reagent with a cephalosporin substituted at the 3 position with a chloro, oxy, amino or sulfide moieties.

Abstract: 7.beta.-Acylamino-3-azido-3-cephem-4-carboxylic acid esters are obtained with the corresponding 3-halo or 3-sulfonyloxy-3-cephem esters and an alkali metal azide. The 3-azido compounds as the free acids or salts are antibacterial agents while in esterified form react with alcohols and phenols to provide 2-alkoxy (or 2-phenoxy)-3amino-3-cephem esters and isomeric ring expanded 4,7-bicyclo .beta.-lactam compounds, namely [2R-(2.alpha.,7.alpha.,8.beta.)-4-alkoxy (or 4-phenoxy)-9-oxo-8-acylamino-6-thia-1,3-diazabicyclo[5.2.0]non-3-ene-2-car boxylic acids and esters and the corresponding 3-alkoxy (or 3-phenoxy) 1,4-diazabicyclo[5.2.0]non-3-ene-2-carboxylic acids and esters. These reaction products obtained with the azide possess antibacterial properties.

Abstract: 7-Acylamido-2-halomethylidene-3-methyl and 3-acetoxymethyl-3-cephem-4-carboxylic acids and esters are prepared via reaction of the corresponding 2-exomethylene-3-cephem ester sulfoxides with chloro (or bromo) dimethyliminium chlorides (or bromides). The 2-halomethylidene derivatives are useful as antimicrobial agents and intermediates to novel 2-acyloxymethylidene cephalosporins and to the known 2-aryl (or alkyl) mercaptomethylidene cephalosporins.

Abstract: 7-Acylamido-2-halomethylidene-3-methyl and 3-acetoxymethyl-3-cephem-4-carboxylic acids and esters are prepared via reaction of the corresponding 2-exomethylene-3-cephem ester sulfoxides with chloro (or bromo) dimethyliminium chlorides (or bromides). The 2-halomethylidene derivatives are useful as antimicrobial agents and intermediates to novel 2-acyloxy-methylidene cephalosporins and to the known 2-aryl (or alkyl) mercaptomethylidene cephalosporins.

Abstract: 7-Acylamino-2-halomethylidene-3-methyl and 3-acetoxymethyl-3-cephem-4-carboxylic acids and esters are prepared via reaction of the corresponding 2-exomethylene-3-cephem ester sulfoxides with chloro (or bromo) dimethyliminium chlorides (or bromides). The 2-halomethylidene derivatives are useful as antimicrobial agents and intermediates to novel 2-acyloxymethylidene cephalosporins and to the known 2-aryl (or alkyl) mercaptomethylidene cephalosporins.

Abstract: Ozonolysis of 3-bromomethyl-2-cephem-4-carboxylic acid esters provides 1-(1-protected carboxy-2-hydroxy-3-bromo-1-propenyl)-3-amido(or imido)-4-formylthio-azetidin-2-ones, useful as intermediates in the preparation of cephalosporin antibiotics.

Abstract: 7-Acylamido-3-hydroxy-3-cephem-4-carboxylic acid ester sulfoxides are chlorinated and reduced in a single step process with phosphorus trichloride in dimethylformamide to provide 7-acylamido-3-chloro-3-cephem-4-carboxylic acid ester sulfides.

Abstract: Ozonolysis of 3-bromomethyl-2-cephem-4-carboxylic acid esters provides 1-(1-protected carboxy-2-hydroxy-3-bromo-1-propenyl)-3-amido(or imido)-4-formylthio-azetidin-2-ones, useful as intermediates in the preparation of cephalosporin antibiotics.

Abstract: 7-Acylamido-3-exomethylenecepham ester sulfoxides are reacted with ozone to provide the corresponding 3-hydroxy-3-cephem ester sulfoxides, intermediates for 3-methoxy and 3-halo substituted cephalosporin antibiotics; e.g., p-nitrobenzyl 7-phenoxyacetamido-3-exomethylenecepham-4-carboxylate-1-oxide provides the corresponding 3-hydroxy-3-cephem ester sulfoxide.

Abstract: Intermediate C-3 1-hydroxyalkyl or 1-hydroxyarylalkyl cephems, prepared by reacting Grignard reagents at low temperature with 3-formyl-2-cephem compounds, are oxidized to the corresponding 7-acylamino-3-acyl-2(or 3)cephem-4-carboxylic acids and esters thereof, which are useful as antibiotics or as intermediates in preparing antibiotic substances.

Abstract: 7-Acylamino and 7-amino-3-(substituted)carbonylamino-3(or 2)-cephem-4-carboxylic acids and esters thereof, which are useful as antibiotics or as intermediates in preparing antibiotic substances respectively, are prepared from 7-acylamino-3-azidocarbonyl-2(or 3)-cephem-4-carboxylic acid esters via the corresponding thermally derived 3-isocyanatocephem derivatives.

Abstract: 7-Acylamino and 7-amino-3-carboxy-3-cephem-4-carboxylic acids and derivatives thereof, which are useful as antibiotics or as intermediates in preparing antibiotic substances, are prepared by an NBS oxidation of acetal derivatives of 3-formyl cephalosporins.

Abstract: 7-Acylamino-2-(substituted ethyl)-3-(substituted alkyl)-3-cephem-4-carboxylic acids and esters are prepared via carbanion addition to 2-methylene-3-cephem sulfoxides to provide antibiotic cephalosporin Michael adducts.