反应详情

A mixture of benzhydryl 7-[2-(2-formamidothiazol-4-yl)-2-methoxyiminoacetamido]-3-triphenylphosphoranylidenemethyl-3-cephem-4-carboxylate (syn isomer) (2.2 g), 36% aqueous formaldehyde (20 ml) and tetrahydrofuran (60 ml) were stirred at ambient temperature for 12.5 hours. After addition of ethyl acetate (100 ml) to the reaction mixture, the organic layer was separated out, washed with 10% hydrochloric acid and an aqueous solution of sodium chloride, and then dried over anhydrous magnesium sulfate. Removal of the solvent gave a residue, which was pulverized with diethyl ether, and chromatographed on silica gel using chloroform and then a mixture of chloroform and acetone (19:1 and 9:1 by volume) as an eluent. The fractions containing the desired compound were collected and evaporated to give benzhydryl 7-[2-(2-formamidothiazol-4-yl)-2-methoxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylate (syn isomer) (0.25 g).

1. customthe organic layer was separated out
2. washwashed with 10% hydrochloric acid
3. dry with materialan aqueous solution of sodium chloride, and then dried over anhydrous magnesium sulfate
4. customRemoval of the solvent
5. customgave a residue, which
6. customchromatographed on silica gel
7. additiona mixture of chloroform and acetone (19:1 and 9:1 by volume) as an eluent
8. additionThe fractions containing the desired compound
9. customwere collected
10. customevaporated