反应详情

Analogously to the process described in Example 1 there is obtained from 12.3 g of pyridine-4-carboxaldehyde-1-oxide, 25.7 ml of ethyl acetoacetate and 10 ml of 30% aqueous ammonia in 20 ml of absolute ethanol, 2,6-dimethyl-4-(1-oxido-4-pyridyl)-1,4-dihydropyridine-3,5-dicarboxylic acid diethyl ester which, after recrystallisation from 100 ml of isopropanol, melts at 229°-231°.