摘要:
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.
摘要:
Novel 3-acyloxymethyl-cephem compounds of the formula: ##STR1## wherein R.sup.1 is hydrogen or an acyl group; W is acetonyl, or a group represented by --X--COOH or --X--OH (X is an organic residue) or salts thereof were found to be useful as starting materials for preparing cephalosporins of the formula: ##STR2## wherein R.sup.3 stands for a residue of a nucleophilic compound and R.sup.1 has the same meaning as above.
摘要:
The compounds of this invention are 7.beta.-hydroxy-3-heterocyclicthiomethyl cephalosporins useful as intermediates for the preparation of 7.beta.-acyloxy cephalosporins.
摘要:
The invention relates to a novel method for the preparation of a 7.beta.-acylamido-3-bromomethylceph-3-em-4-carboxylic acid-1-oxide compound by brominating a 7.beta.-acylamido-3-methylceph-3-em-4-carboxylic acid-1-oxide compound.
摘要:
Antibacterial cephalosporins of the formula ##STR1## wherein Acyl is an acyl group; R is a hydrogen or methoxy, R.sup.1 is a hydrocarbyl group containing 1 to 8 carbon atoms; R.sup.2 is a hydrogen, alkali metal, alkaline earth metal, halo-alkaline earth metal group or acyl group containing 1 to 12 carbon atoms; R.sup.3 is a hydrogen, pharmaceutically acceptable cation, or ester residue; or when R.sup.2 and R.sup.3 are both hydrogens, they can be combined to form a lactone ring; the broken line shows a double bond at position 2 or 3; and n is zero or one, and processes for preparing them by the reaction of the compound shown by above formula in which R.sup.1 and R.sup.2 combined to show a bond, with a Grignard type or organometallic reagent to introduce R.sup.1, followed by acylation, oxidation, reduction, double bond migration, or other reactions.
摘要:
R-sulfoxides of the formulae ##STR1## wherein ##STR2## represents an usual penicillin or cephalosporin amide group and X is selected from the group consisting of hydrogen, hydroxy, an alkanoyloxy and the residue of a nucleophilic agent and their salts and esters are prepared by oxidation of the corresponding penicillins and cephalosporins to convert the sulfur atom in the ring to a sulfoxide group and separating and isolating the penicillin- or cephalosporin R-sulfoxide so formed from the reaction mixture or by acylation of the free amino group of the intermediate 6-aminopenicillanic acid R-sulfoxide and 7-aminocephalosporanic acid R-sulfoxide and derivatives. A preferred straight oxidation method is the photosensitized oxygenation method.
摘要:
An improved process for preparing the compound 7.beta.-(2-thienylacetamido)-7-methoxy-3-carbamoyloxymethyl-3-cephem-4-carboxylic acid or its esters, from the compound 7.beta.-(D-5-amino-5-carboxyvaleramido)-3-carbamoyloxymethyl-7-methoxy-3-cephem-4-carboxylic acid, by conducting the transacylation of the latter compound in the presence of commercially available alumino-silicate zeolites, also known as "molecular sieves." The process can be employed to prepare a cephalosporin with a desired 7-acylamido group from cephalosporins having a broad range of different 7-acylamido groups without having to isolate and purify a 7-amino intermediate. The final products have utility as broad spectrum antibiotics.
摘要:
Reaction of 3-hydroxy cephalosporins with alkylfluorosulfonates in the presence of a base provides 3-alkoxy cephalosporins which are useful as intermediates for cephalosporin antibiotic preparation.
摘要:
Cephalosporin intermediates of the formulas ##STR1## wherein R is lower alkyl, 2,2,2-trichloroethyl, diphenylmethyl, p-methoxybenzyl, or p-nitrobenzyl; R.sub.1 is lower alkyl or phenyl; R.sub.2 is hydrogen or acetoxy; R.sub.4 is methyl or ethyl; and R.sub.5 is hydrogen, methyl, or methoxy; are disclosed. Methods of reacting these intermediates to prepare antibacterially active cephalosporins are disclosed.