Water → Acetoxymethyl 7-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylate

Participants

Reaction Steps

To a solution of sodium 7-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylate (syn isomer)(2.2 g) in N,N-dimethylformamide (25 ml) was added dropwise a solution of iodomethyl acetate (1 g) in N,N-dimethylformamide (3 ml) below 5° C. in the course of 2 minutes, and the mixture was stirred at the same temperature for 15 minutes. The reaction mixture was poured into a mixture of water (100 ml) and ethyl acetate (50 ml), and the separated aqueous solution was extracted with ethyl acetate (30 ml). The combined ethyl acetate solution was washed twice with 5% aqueous sodium bicarbonate and twice with an aqueous sodium chloride, and then dried over anhydrous magnesium sulfate. Removal of the solvent gave a residue, which was pulverized with diisopropyl ether and collected by filtration to obtain acetoxymethyl 7-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylate (syn isomer)(1.6 g), mp 78°-83° C.

Provenance & Evidence