Triethylamine → Benzhydryl (6R,7R)-8-oxo-7-(2-phenylacetamido)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a suspension of 3-hydroxy-7beta-phenylacetylaminocepham-4-carboxylic acid diphenylmethyl ester (2) in dichloromethane (13 parts) cooling at -10° C. under nitrogen are added triethylamine (4 equivalents) and then methanesulfonyl chloride (2.0 equivalents) at -10° C. over 7 minutes. The produced methanesulfonate ester (3) solution is let react at -10° C. for 30 minutes, and diluted with dichloromethane, washed with water, 5% sulfuric acid, and water, dried over sodium sulfate, and concentrated. The residue is crystallized from methanol (4 parts) to give 7beta-phenylacetylamino-3-cephem-4-carboxylic acid diphenylmethyl ester (6). (Yield: 75.4%).

Provenance & Evidence