Synthesis, antitubercular activity, and SAR study of N-substituted-phenylamino-5-methyl-1H-1,2,3-triazole-4-carbohydrazides.

Tuberculosis treatment remains a challenge that requires new antitubercular agents due to the emergence of multidrug-resistant Mycobacterium strains. This paper describes the synthesis, the antitubercular activity and the theoretical analysis of N-substituted-phenylamino-5-methyl-1H-1,2,3-triazole-4-carbohydrazides (8a-b, 8e-f, 8i-j and 8n-o) and new analogues (8c-d, 8g-h, 8l-m and 8p-q). These derivatives were synthesized in good yields and some of them showed a promising antitubercular profile. Interestingly the N-acylhydrazone (NAH) 8n was the most potent against the Mycobacterium tuberculosis H37Rv strain (MIC=2.5 μg/mL) similar to or better than the current drugs on the market. The theoretical structure-activity relationship study suggested that the presence of the furyl ring and the electronegative group (NO(2)) as well as low lipophilicity and small volume group at R position are important structural features for the antitubercular profile of these molecules. NMR spectra, IR spectra and elemental analyses of these substances are reported.