ABSTRACT
Cyanoacetanilides (1a,b) were reacted with o-hydroxyaldehydes under different
conditions. Thus, cyclocondensation of 1a,b with salicylaldehyde, 2-hydroxy-1-
naphth-aldehyde and 7-hydroxy-5-methoxycoumarin-6-carboxaldehyde in ethanolic
amm. acetate afforded the corresponding 2-iminochromene derivatives 3,7 and 9
respectively. On the other hand, repeating the same reaction in presence of
Ac2O/AcONa, the corresponding chromen-2-one derivatives 4, 8 and 10 were
obtained. Compounds 4,8 and 10 were also synthesized through the hydrolysis of 2-
imino derivatives using EtOH/HCl. A number of chromeno[3,4-c]-pyridine derivatives
11,13,14 and 16 were prepared from the reaction of 2-iminochromenes with
malononitrile, ethyl cyanoacetate, and cyanoacetanilide. Some of these compounds
were screened in vitro for their antimicrobial activities.