Ammonium Chloride-Catalyzed Three-Component Reaction for the Synthesis of Fused 4H-Chromene Derivatives in Aqueous Medium

Abstract

An efficient one-pot process was developed to synthesize 4<i>H</i>-chromene derivatives using a three-component reaction involving salicylaldehydes, cyclic 1,3-diketones, and thiols in an aqueous medium at room temperature. This protocol was accomplished using the inexpensive and readily available catalyst NH₄Cl. The attractive features of this protocol are: use of inexpensive catalyst NH₄Cl, good yields, and mild and environmentally benign reaction conditions.