Dimethyl Sulfoxide → 2,2,2-Trichloroethyl 3-hydroxy-3-methyl-7-(2-phenylacetamido)cepham-4-carboxylate

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Reaction Steps

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.

Provenance & Evidence