Chloroform → benzhydryl 7-[2-allyloxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3-[(Z)-2-(2-pyridyl)vinylthio]-3-cephem-4-carboxylate

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Reaction Steps

A mixture of benzhydryl 7-amino-3-[(Z)-2-(2-pyridyl) -vinylthio]-3-cephem-4-carboxylate (600 ml) and bis-(trimethylsilyl)urea (981 mg) in methylene chloride (6 ml) was stirred at 30°~35° C. for 30 minutes to give a clear solution. To the clear solution was added 2-allyloxyimino-2-(5-amino-1,2,4-thiadiazol-3yl) acetyl chloride monohydrochloride (syn isomer) (480 mg) at -20° C. and the mixture was stirred for 30 minutes at -10°~-15° C. The mixture was poured into a mixture of chloroform and water. The organic layer was separated and concentrated in vacuo to give a residue. The residue was dissolved in a mixture of tetrahydrofuran, ethyl acetate and dilute aqueous solution of sodium bicarbonate. The organic layer was separated, washed with dilute aqueous solution of sodium bicarbonate and a saturated aqueous solution of sodium chloride in turn, dried over magnesium sulfate and concentrated in vacuo, and the residue was triturated with diisopropyl ether to give benzhydryl 7-[2-allyloxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) -acetamido]-3-[(Z)-2-(2-pyridyl)vinylthio]-3-cephem-4-carboxylate (syn isomer) (848 mg).

Provenance & Evidence