Structure of reaction products of 3-cyanochromones with ethylenediamine
A reaction of 3-cyanochromones with ethylenediamine in ethanol afforded N,N′-ethyl-ene-bis(2-amino-3-iminomethylchromones), which depending on the time of reflux in acetic acid give 2-amino-3-formylchromones or products of their dimerization, 2-(chromon-3-yl)-5H-chromeno[2,3-d]pyrimidin-5-ones.