反应详情

The compounds of the Formula I wherein Q is a carboxylic acid group can be prepared for example, by the acylation of a 3-halo-3-cephem nucleus ester with tert-butyl phenylmalonic acid chloride, or with tert-butyl 2-thienylmalonic acid chloride in the presence of a hydrogen halide acceptor such as sodium bicarbonate. For example, tert-butyl 7-amino-3-chloro-3-cephem-4-carboxylate is reacted with 2 equivalents of tert-butyl phenylmalonyl chloride in acetone at a temperature of about 5°C. and in the presence of excess sodium bicarbonate to provide, tert-butyl 7-(α-tert-butyloxycarboxylphenylacetamido)-3-chloro-3-cephem-4-carboxylate. Removal of both tert-butyl ester groups with 90% formic acid provides the diacid, 7-(α-carboxyphenylacetamido)-3-chloro-3-cephem-4-carboxylic acid.

1. customto provide
2. customRemoval of both tert-butyl ester groups with 90% formic acid