2,3-ピリジンジカルボン酸ジエチルエステル類の新規な合成法

Deithyl 2, 3-pryridine dicarboxylates 3 were easily prepared in one pot synthesis by the reaction of a-chlorooxaloacetate 1, a, p-unsaturated aldehydes 2 and ammonia. Especially, diethyl 5-ethyl-2, 3-pyridine dicarboxylate 3a was obta i ned in a good yield (81%) by the reaction of 1, 2-ethyl-2-prop enal 2a and ammonia in chloroform using an autoclave. In the reaction in an autoclave, the yield of 3 a in chlorobenzene or toluene was similar to that of chloroform. But under atmospheric pressure, the yield of 3a was lower in toluene, benzene, and ethanol than in chlorobenzene.