Sodium Chloride → benzhydryl 7-[2-(5-amino-1,2,4-thiadiazol-3yl)-2-carboxymethoxyiminoacetamido]-3-[(Z)-2-(3-pyridyl)vinylthio]-3-cephem-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of benzhydryl 7-amino-3-[(Z)-2-(3-pyridyl)vinylthio]-3-cephem-4-carboxylate (3 g) and bis(trimethylsilyl)urea (3.70 g) in tetrahydrofuran (45 ml) was added 2-(5-amino-1,2,4-thiadiazol-3yl)-2-carboxymethoxyiminoacetic methanesulfonic anhydride (syn isomer) (1.45 g) at -30° C. The mixture was stirred at -20~-10° C. for 1 hour, at 0° C. overnight and at ambient temperature for 2 days. The mixture was poured into a mixture of ethyl acetate and a saturated aqueous solution of sodium chloride. The organic layer was separated, dried over sodium sulfate and concentrated in vacuo to give a precipitate. The precipitate was collected and washed with ethyl acetate and diisopropyl ether in turn to give benzhydryl 7-[2-(5-amino-1,2,4-thiadiazol-3yl)-2-carboxymethoxyiminoacetamido]-3-[(Z)-2-(3-pyridyl)vinylthio]-3-cephem-4-carboxylate (syn isomer) (1.95 g).

Provenance & Evidence