反应详情

A solution of aluminum bromide (3.4 g.) in dried dichloromethane (20 ml.) was dropwise added at -10° C. over about 10 minutes to a solution of 2,2,2-trichloroethyl 2-methyl-2,3-methylene-6-(2-phenylacetamido)penam-3-carboxylate (4.6 g.) in dried dichloromethane (30 ml.). After addition, the reaction mixture was stirred for 4.5 hours at room temperature, washed in turn with 2% hydrochloric acid (30 ml.) three times, a saturated sodium bicarbonate aqueous solution and a saturated sodium chloride aqueous solution. After drying over magnesium sulfate, the solvent was distilled off and the residue was washed with ether and collected by filtration to give 2,2,2-trichloroethyl 2-methyl-7-(2-phenylacetamido)-3-cephem-4-carboxylate (3.3 g.). This compound was recrystallized from ethanol to give crystals, mp 175° to 178° C.

1. additionAfter addition
2. washwashed in turn with 2% hydrochloric acid (30 ml.) three times
3. dry with materialAfter drying over magnesium sulfate
4. distillationthe solvent was distilled off
5. washthe residue was washed with ether
6. filtrationcollected by filtration