New 2 - acyloxy cephalosporin compounds having an antibiotic aktivitaet, for their preparation suitable intermediates and process for the preparation of the compounds and intermediates

摘要

1,269,147. 2-Acyloxy cephalosporins. ELI LILLY & CO. 6 Oct., 1969 [7 Oct., 1968], No. 49068/69. Heading C2A. Novel 2 - acyloxy - 7 - (protected amino) cephalosporins having the formula wherein R is a protected amino group; RSP2/SP is methyl, in which RSP5/SP is H, C 1 to C 6 alkyl, C 5 to C 7 cycloalkyl, or a radical of formula where Y is F, Cl, Br, C 1 to C 3 alkoxy, -NO 2 , or -CF 3 , m = 0 or 1, and s is 0, 1, or 2; RSP3/SP is C 2 to C 8 alkanoyloxy or C 6 to C 8 cycloalkanoyloxy; and RSP4/SP is H or a residue of an esterifying alcohol, are prepared by reacting a protected 7-amino cephalosporin ester of formula wherein RSP1/SP is a residue of an esterifying alcohol and R and RSP2/SP are as above, with a lead tetraacylate of formula Pb(RSP3/SP) 4 , RSP3/SP being as above and if required converting the ester group RSP1/SP to hydrogen. The novel compounds may have antibiotic activity, or if not, provide intermediates for preparing cephalosporin antibiotics, e.g. by removing the N-protecting group and reacylating, or replacing the RSP2/SP group by other groups by conversion to the 3-(bromomethyl) derivative followed by reaction with a suitable nucleophilic compound. The preparative reaction is preferably carried out in a solvent, e.g. ethers, tertiary amides and alcohols, or hexamethylphosphoramide. Typical N-protecting groups include tritylamino, (trimethylsilyl)amino, acylamido and phthalimido. The ester group RSP1/SP may be removed by treating with Zn and CH 3 .COOH, or with trifluoracetic acid, or by hydrogenation using palladium black.