反应详情

A solution of 37.3 g of t-butyl 3-bromomethyl-7-phenylacetamido-3-cephem-4-carboxylate-1-oxide in 130 ml of trifluoroacetic acid was stirred for 15 minutes at room temperature and then the solvent was removed by evaporation under vacuo. After addition of 100 ml of 1,2-dichloroethane, evaporation to dryness was repeated. Ether was added to the residue and the crystals were vacuum filtered, washed with ether and dried under vacuo to obtain 33.7 g of 3-bromomethyl-7-phenylacetamido-3-cephem-4-carboxylic acid-1-oxide as an almost colorless solid having the following characteristics:

1. customthe solvent was removed by evaporation under vacuo
2. additionAfter addition of 100 ml of 1,2-dichloroethane, evaporation to dryness
3. additionEther was added to the residue
4. filtrationfiltered
5. washwashed with ether
6. customdried under vacuo