反应详情

208 mg of N-trimethylsilylacetamide (1.59 mmoles) were added to a suspension of 383 mg (1.14 mmoles) of 7-benzamido-3-methyl-3-cephem-4-carboxylic acid-1-oxide in 25 ml of dichloromethane, and after stirring for 11/2 hours at room temperature, a clear solution was obtained, which was diluted with dichloromethane to 50 ml. 200 mg of amidosulfonic acid (1.04 mmoles) were added thereto and the mixture was cooled in an ice-bath. Bromination was carried out in half an hour using 310 mg (1.74 mmoles) of N-bromosuccinimide as the brominating agent to obtain a 48% yield of trimethylsilyl 7-benzamido-3-bromomethyl-3-cephem-4-carboxylate-1-oxide.

1. customa clear solution was obtained
2. temperaturethe mixture was cooled in an ice-bath
3. waitBromination was carried out in half an hour