反应详情

A mixture of 530 mg of 5-acetonyl-3-chloromethyl-1,2,4-oxadiazole, 450 mg of 3-nitrobenzaldehyde and 560 mg of 2-(n-propoxy)ethyl 3-aminocrotonate in 3 ml of isopropyl alcohol was heated under reflux for 8 hours. The reaction mixture was concentrated in vacuo and the residue was chromatographed on silica gel using benzene-acetonitrile (10:1) as eluent to give 1.35 g of 2-(n-propoxy)ethyl 1,4-dihydro-2,6-dimethyl-3-(3-chloromethyl-1,2,4-oxadiazol-5-yl)-4-(3-nitrophenyl)pyridine-5-carboxylate. Recrystallization from n-hexane-isopropylalcohol afforded pale yellow crystals, m.p. 129°-130° C.

1. temperaturewas heated
2. temperatureunder reflux for 8 hours
3. concentrationThe reaction mixture was concentrated in vacuo
4. customthe residue was chromatographed on silica gel