反应详情

2,2,2-Trichloroethyl 2-bromomethyl-2-methyl-6-(2-phenylacetamido)penam-3-carboxylate (0.54 g) was dissolved in absolute dimethylsulfoxide (5 ml). To this solution was added silver fluoroborate (0.20 g) and then the mixture was stirred under shielding from light for 3 hours at room temperature. To the solution was added a solution of triethylamine (0.1 g) in dimethylsulfoxide (0.5 ml) and the solution was further stirred for 5 hours and then allowed to stand overnight at room temperature. Precipitates were filtered off and the filtrate was poured into ice-water and then extracted with ethyl acetate. The extract was washed with water and dried. The residue obtained by distilling off the solvent under reduced pressure was crystallized by a small amount of ether to give colorless crystals of 2,2,2-trichloroethyl 3-hydroxy-3-methyl-7-(2-phenylacetamido)cepham-4-carboxylate (280 mg) (58 %). This substance was recrystallized from a mixed solvent of benzene-n-hexane to give colorless needles melting at 169° to 171°C.

1. stirringthe solution was further stirred for 5 hours
2. waitto stand overnight at room temperature
3. customPrecipitates
4. filtrationwere filtered off
5. additionthe filtrate was poured into ice-water
6. extractionextracted with ethyl acetate
7. washThe extract was washed with water
8. customdried
9. customThe residue obtained
10. distillationby distilling off the solvent under reduced pressure
11. customwas crystallized by a small amount of ether