The condensation of substituted 6-amino-2-(1H)-pyridones with ethylethoxymethylene cyanoacetate gives rise not only to the two corresponding olefines, as expected, but also to a third tautomeric fused form. The equilibrium between these 3 forms in solution is studied by NMR. These compounds are excellent precursors for the synthesis of pyrido [1,2-a] pyrimidines.
取代的6-
氨基-2-(1H)-
吡啶酮与乙氧基亚甲基
氰基
乙酸酯的缩合不仅产生了预期的两种相应的烯烃,而且还产生了第三种互变异构的稠合形式。通过NMR研究溶液中这三种形式之间的平衡。这些化合物是用于合成
吡啶并[1,2-a]
嘧啶的极好的前体。