反应详情

A mixture of 12.5 g of t-butyl 7-benzamido-2-bromo-3-bromomethyl-3-cephem-4-carboxylate-1-oxide and 50 ml of trifluoroacetic acid was stirred at room temperature for 15 minutes and was then evaporated to dryness under vacuo. 25 ml of dichloromethane were added to the residue and evaporation to dryness was repeated. A 1:1 mixture of ether and heptane was added to the residue and the formed crystals were vacuum filtered and washed with the same mixture to obtain 9.6 g of 7-benzamido-2-bromo-3-bromomethyl-3-cephem-4-carboxylic acid-1-oxide as an almost colorless solid, having the following characteristics:

1. customwas then evaporated to dryness under vacuo
2. addition25 ml of dichloromethane were added to the residue and evaporation to dryness
3. additionA 1:1 mixture of ether and heptane
4. additionwas added to the residue
5. filtrationfiltered
6. washwashed with the same mixture