反应详情

Working as in example 19 for the preparation of ethyl 6-[4-(benzyloxy)phenyl]-3-oxo-2,3-dihydropyridazine-4-carboxylate, but starting with 31.1 g of diethyl hydroxy(pyridin-2-oxoethyl)malonate, 11.55 g of hydrazine dihydrochloride and 700 cm3 of ethanol, and after purification by chromatography on silica gel (particle size 40-63 μm, under an argon pressure of 150 kPa), eluting with dichloromethane, followed by recrystallization from ethanol, 6.9 g of ethyl 6-pyridin-2-yl-3-oxo-2,3-dihydropyridazine-4-carboxylate were obtained in the form of a yellow solid melting at 182° C.

1. customafter purification by chromatography on silica gel (particle size 40-63 μm
2. washunder an argon pressure of 150 kPa), eluting with dichloromethane
3. customfollowed by recrystallization from ethanol