Facile construction of novel heterocyclic compounds: three-component, one-pot synthesis of 2-hydroxybenzoyl-1,2-dihydropyridine-3-carboxylates, ketones, pyridone-3-carboxylates and benzopyrido-1,3-oxazole-4-carboxylates

Abstract

A facile method has been developed for the preparation of novel heterocyclic compounds by the reaction of 3-formylchromones, benzylamines, and 2-aminophenols with 3-oxobutanoates. 3-Oxobutanoates bearing trifluoro or trichloro substituents and trifluoro containing 1,3-diketones facilitated the reaction. The reaction proceeds via a Schiff base mediated Michael addition followed by the selective addition of enamine to the carbonyl group adjacent to the trihalo group due to a strong electron withdrawing effect. The present three-component, one-pot protocol provided heterocyclic compounds without a catalyst.