One‐Pot Synthesis of 3‐Amino‐1,2,4‐triazoles Using Choline Chloride‐Urea and Their Antibacterial Activities

In this study, a new one‐pot method was proposed for the synthesis of novel and known 3‐amino‐1,2,4‐triazole derivatives in choline chloride/urea (1 : 2) as a biodegradable, nontoxic, biorenewable and inexpensive solvent and reagent. It efficiently catalyzed the reaction between alkyl/aryl hydrazides with urea. Some of the advantages of the proposed method are: eco‐friendly and low‐cost procedure, easy work‐up and purification, good to excellent product yields and acceptable reaction times. This method can be a model for Pellizzari‐type reactions. Antimicrobial activity of the synthesized 1,2,4‐triazoles were evaluated against five Gram‐positive and three Gram‐negative pathogenic bacteria via Kirby‐Bauer disk diffusion method. Triazoles containing 3‐bromophenyl and 4‐(tert‐butyl)phenyl substituents were the most effective antibacterial agents against all tested bacterial strains. In this study, 3‐amino‐1,2,4‐triazole derivatives as potent antibacterial agents were synthesized via a green procedure using the reaction of hydrazides with urea. Choline chloride/urea (1 : 2) was used as reaction media. The products were prepared in this deep eutectic solvent at good to excellent yields.