Cyanoacetamide derivatives were reacted with salicylaldehyde under different conditions afforded chromenes and coumarin derivatives respectively. A number of chromeno [3, 4-c] pyridine derivatives were prepared from the reaction of N-cyclohexyl-2-imino-2H-chromene- 3-carboxamide with malononitrile and/or cynaothiocatemaide. Bischromeno [3, 4-c] pyridine derivatives were prepared from the reaction of N, N'-(ethane-1, 2-diyl) bis (2-imino-2H- ...
