GB1382947A - Process for preparing a desacetoxycephalosporin compound and 3-nitrooxycepham compounds - Google Patents

Abstract

1382947 Reacting 3-halocepham compounds ELI LILLY & CO 18 June 1973 [30 June 1972 (2)] 28800/73 Heading C2C A process for treating a cepham compound comprises reacting a cepham compound of Formula I with AgQ to obtain a mixture comprising a compound of Formula II a compound of Formula III and a compound of Formula IV wherein R is the residue of an imide derived from a dicarboxylic acid, R 1 is a carboxy protecting group, X is chlorine or bromine and Q is -ONO 2 or wherein R 2 is C 1-4 alkyl or C 5-6 cyclo-alkyl. The compound of Formula III may be converted by heating to 80 # 175‹ C. into the compound of Formula II. The following treatments are exemplified (1) the reaction between p-nitrobenzyl 7 - phthalimido - 3α - methyl - 3#- chlorocepham-4-carboxylate and silver nitrate to form a mixture of p-nitrobenzyl 7-phthalimido- 3α - methyl - 3# - nitroxycepham - 4 - carboxylate, p - nitrobenzyl 6 - phthalimido - 2amethyl - 2# - nitrooxymethyl penam - 3 - carboxylate and p-nitrobenzyl-7-phthalimido-3- methyl - 3 - cepham - 4 - carboxylate, (ii) modifications of (i) wherein the starting material is the p-methoxy- and not the p-nitro-cepham compound, (iii) p-methoxybenzyl 7-phthalimido- 3α - methyl - 3# - nitroxy cepham-4 - carboxylate prepared in (ii) is converted by heating to methoxybenzyl 7-phthalimido-3-methyl-3-cepham-4-carboxylate, (iv) modification of (i) wherein the starting material is the methyl and not the p-nitrobenzyl cepham compound, (v) methyl 7 - phthaleimido - 3α - methyl - 3#- nitro-oxycepham-4-carboxylate is converted by heating to methyl 7-phthalimido-3-methyl-3- cepham-4-carboxylate, and (vi) modification of (iv) wherein silver acetate is used instead of silver nitrate.