Synthesis of some new 6-aryl-3-(4-isopropylphenyl)[1,2,4]triazolo[3,4-b][1,3,4] thiadiazoles and its anti-microbial study

New series of fused 1,2,4-triazoles, i.e., 3-(4-isopropylphenyl)-6-substituted phenyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles (5a-5j) have been synthesized via a four-step procedure and using eco-friendly reaction condition at some steps of the synthesis. It was adopted by the formation of hydrazide of methyl 4-isopropylbenzoate (1) followed by reaction with CS2 in basic media to afford potassium salt, which on cyclized to our essential step, 4-amino-5-(4-isopropylphenyl)-4H-1,2,4-triazole-3-thiol (4). The desired adducts (5a-5j) were formed by (4) on reaction with various aromatic acids in POCl3 media. The newly synthesized triazolo- thiadiazoles have been characterized by different spectroscopic techniques and investigated for their in vitro antibacterial and antifungal activity. It was revealed that the compounds 5a, 5c, 5h, and 5i showed interesting antibacterial and antifungal activity compared to the used reference standard