Novel synthesis of 2-oxo-2H-benzopyrano[2,3-d]pyrimidines

The synthesis of novel substituted 3-cyanoiminocoumarins and corresponding N-ethoxycarbonyl iminocoumarins is described. The condensation of N-ethoxycarbonyl-3-cyano-7-diethylamino iminocoumarin with amines as N-nucleophiles yields substituted 2-oxo-2H-benzopyrano[2,3-d]pyrimidines having promising optical properties.