Pseudo four-component reaction of salicylaldehydes and cyclic ketones with two molecules of malononitrile: A facile and efficient way to synthesize 4-[2-(dicyanomethylene)cyclic or heterocyclic]-2-amino-4H-chromenes

A new type of catalytic cascade pseudo four-component reaction has been found. The simple and facile pseudo four-component reaction of salicylaldehydes and cyclic or heterocyclic ketones with two molecules of malononitrile catalyzed by sodium acetate at ambient temperature results in the formation of 4-substituted 2-amino-4H-chromenes in 70-90% yields. Thus, a new simple and efficient 'one-pot' method to synthesize substituted 2-amino-4H-chromenes was found directly from such reasonable starting compounds as salicylaldehydes, cyclic or heterocyclic ketones and malononitrile.