A novel one-pot synthesis method of 3,4,5-triaryl-substituted 1,2,4-triazoles

A novel method for the preparation of 3,4,5-triaryl-substituted 1,2,4-triazoles by the reaction of hydrazides with secondary amides in polyphosphoric ester has been developed. The new method is characterized by mild conditions and ease of synthesis, including the stages of isolation and purification of the product. Additionally, product structures were confirmed by counter synthesis. It was shown that the proposed method is suitable for producing 1,2,4-triazoles with phenolic substituents without the stages of the protection and deprotection of the hydroxyl group. Using the new method, five 3,4,5-substituted 1,2,4-triazoles were obtained for the first time.