反应详情

A mixture of 500 mg of the oxadiazole intermediate prepared above, 240 mg of benzaldehyde and 260 mg of methyl 3-aminocrotonate in 5 ml of isopropyl alcohol was heated under reflux for 8 hours and then concentrated to dryness in vacuo. The residue was chromatographed on silica gel using chloroform-methanol (20:1, v/v) as eluent to give 600 mg of methyl 1,4-dihydro-2,6-dimethyl-3-(3-piperidinomethyl-1,2,4-oxadiazol-5-yl)-4-phenylpyridine-5-carboxylate as pale yellow crystals, mp. 187°-188° C. (decomp.).

1. customprepared above
2. temperatureunder reflux for 8 hours
3. concentrationconcentrated to dryness in vacuo
4. customThe residue was chromatographed on silica gel