Direct Synthesis of N-Acylhydrazones from N-Substituted Hydrazines, Aldehydes, and Carboxylic Acids via Preferential Imine Formation and Selective Secondary Amine Monoacylation.

A three-component reaction of N-substituted hydrazines, aldehydes, and carboxylic acids has been achieved for the synthesis of N-acylhydrazones via the preferential formation of imines and the selective monoacylation of N-substituted hydrazones. The reaction has a wide substrate scope and functional group tolerance. The synthetic utility has been illustrated by the facile construction of valuable bioactive molecules and late-stage functionalization of pharmaceuticals.