Pyridine → HCID 14672337, compound

Participants

Reaction Steps

To a cooled (0° C.) solution of 18.3 g (33.0 mM) of 4-methoxybenzyl 7β-phenylacetamido-3-[(Z)-2-methoxycarbonylvinylthio]-3-cephem-4-carboxylate in 200 ml of dry dichloromethane were added 7.82 g (99.0 mM) of pyridine and 13.7 g (65.8 mM) of phosphorus pentachloride, and the reaction temperature was raised to room temperature for a period of 30 minutes, and the mixture was stirred at the same temperature for 1 hour. To the cooled (-50° C.) reaction solution was added 100 ml of dry methanol, and the mixture was stirred at -20° C. for 1 hour. Upon continued cooling of the reaction mixture to -50° C., 100 ml of water was added, and the mixture was stirred under ice-cooling for 40 minutes. The mixture was made weakly basic by addition of a saturated aqueous sodium bicarbonate solution, and extracted with 300 ml of ethyl acetate, and the extract was washed with 200 ml of a saturated aqueous sodium chloride solution and dried over anhydrous magnesium sulfate. The solvent was evaporated, and diethyl ether was added to the residue for powdering to give 10.6 g of 4-methoxybenzyl 7β-amino-3-[(Z)-2-methoxycarbonylvinylthio]-3-cephem-4-carboxylate.

Provenance & Evidence