One-step synthesis of chromene-3-carboxamide, bis-chromene, chromeno[3,4-c]pyridine and bischromeno[3,4-c]pyridine derivatives for antimicrobial evaluation

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-chromene-3-carboxamide) with malononitrile and/or N-alkyl-2-cyanoacetamide derivative with 2-iminochroemen derivative, respectively. Some of these compounds were screened for their antimicrobial activities.