反应详情

To a solution of phosphorus pentachloride (455 mg) in methylene chloride (15 ml) was added 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(2-cyclopenten-1-yl)oxyiminoacetic acid (syn isomer) (557 mg) at -20° C. The mixture was stirred at -20~-10° C. for 30 minutes. The resultant mixture was added to a solution of benzhydryl 7-amino-3-[(Z)-2-(3-pyridyl)vinylthio]-3-cephem-4-carboxylate (1 g) and bis(trimethylsilyl)urea (2 g) in methylene chloride (20 ml) at -20° C. The mixture was stirred at -20~-10° C. for 30 minutes. The mixture was concentrated in vacuo and the residue was dissolved in a mixture of water (100 ml), sodium bicarbonate (920 mg), ethyl acetate and tetrahydrofuran. The organic layer was separated, washed with water and a saturated aqueous solution of sodium chloride in turn, dried over magnesium sulfate, concentrated in vacuo, and the residue was triturated with diethyl ether to give benzhydryl 7-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(2-cyclopenten-1-yl)oxyiminoacetamido]-3-[(Z)-2-(3-pyridyl)vinylthio]-3-cephem-4-carboxylate (syn isomer) (1.12 g).

1. stirringThe mixture was stirred at -20~-10° C. for 30 minutes
2. concentrationThe mixture was concentrated in vacuo
3. dissolutionthe residue was dissolved in a mixture of water (100 ml), sodium bicarbonate (920 mg), ethyl acetate and tetrahydrofuran
4. customThe organic layer was separated
5. washwashed with water
6. dry with materiala saturated aqueous solution of sodium chloride in turn, dried over magnesium sulfate
7. concentrationconcentrated in vacuo
8. customthe residue was triturated with diethyl ether