反应详情

A mixture consisting of 400.5 mg (1.20 mmoles) of 7-benzamido-3-methyl-3-cephem-4-carboxylic acid-1-oxide, 0.69 g (4.3 mmoles) of N-trimethylsilylurethane and 20 mg of bis-(trimethylsilyl)-sulfate in 40 ml of dichloromethane was refluxed for 3/4 hours after which a clear solution was obtained. This was cooled in an ice-bath and bromination was carried out after the addition of 200 mg (2.04 mmoles) of amidosulfonic acid using 325.3 mg (1.83 mmoles) of N-bromosuccinimide as the brominating agent. The bromination took half an hour to obtain a 65% yield of trimethylsilyl 7-benzamido-3-bromomethyl-3-cephem-4-carboxylate-1-oxide.

1. temperaturewas refluxed for 3/4 hours after which a clear solution
2. customwas obtained
3. temperatureThis was cooled in an ice-bath
4. waitThe bromination took half an hour