Ethyl Acetate → 1-Propionyloxyethyl 7-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylate

Participants

Reaction Steps

To a solution of 7-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylic acid (syn-isomer, 100 g) in dimethylsulfoxide (650 ml) was added potassium carbonate (21.6 g). Thereto was added 1-chloroethyl propionate (42.8 g) at 40° C. and the mixture was stirred at the same temperature for 2 hours. The reaction mixture was poured into a mixture of ice-water (3 l) and ethyl acetate (2 l), and the separated organic layer was washed in turn with 5% aqueous sodium bicarbonate (300 ml×2), water (300 ml) and an aqueous sodium chloride, followed by drying over magnesium sulfate. After treating with activated charcoal, the solvent was removed by evaporation, and the residue was pulverized with diisopropyl ether to give 1-propionyloxyethyl 7-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylate (syn-isomer, 80 g).

Provenance & Evidence