Triethylamine → Benzhydryl 7-amino-3-cephem-4-carboxylate

Participants

Reaction Steps

To a solution of 3-acetoxy-7beta-aminocepham-4-carboxylic acid diphenylmethyl ester (4a) in dichloromethane cooling at -25° to -20° C. is added triethylamine (1 to 3 equivalents). The mixture is warmed slowly up to 0° to 5° C. and let stand overnight. To this is added ice-water (20 parts), stirred for 20 minutes, and extracted with dichloromethane. The extract is washed with hydrochloric acid, water, aqueous 7% sodium hydrogen carbonate, and aqueous 5% sodium chloride, dried, and concentrated. The residue is crystallized from ethyl acetate to give 7beta-amino-3-cephem-4-carboxylic acid diphenylmethyl ester (5). Yield 61.0% from (1). mp. 159°-160° C. (decomposition).

Provenance & Evidence