Synthesis of N-Alkyl-2-aryl-5H-imidazo[1,2-b]pyrazol-3-amines by a Three- Component Condensation Reaction.

An efficient method has been developed for the synthesis of a novel series of N-alkyl-2-aryl-5H-imidazo[1,2-b]pyrazol-3-amines in good-to-high yields by the three-component condensation of an aromatic aldehyde, an aminopyrazole, and an isocyanide in acetonitrile with 4-toluenesulfonic acid as a catalyst at room temperature. [ABSTRACT FROM AUTHOR]