An Improved Process for the Preparation of Diphenylmethyl 7β-Phenylacetamido-3-hydroxymethyl-3-cephem-4-carboxylate

摘要

An efficient and improved process for the preparation of diphe-nylmethyl 7 β-phenylacetamido-3-hydroxymethyl-3-cephem-4-car-boxylate was developed. With the commercially available 7-ami-nocephalosporanic acid (7-ACA) as starting material, up to 73.5% overall isolated yield of the titled compound was synthesized in two steps via direct phenylacetylation with phenylacetyl chloride,followed by basic hydrolysis and esterification with diphenyldia-zomethane. The newly developed process obviated the use of protecting groups, reduced the environmental footprint, and could be easily controlled and conveniently scaled up for this pivotal intermediate in cephalosporin chemistry.