Synthesis of novel pyrazole tagged pyridine derivatives; their antimicrobial activity

Abstract

: Novel pyrazole tagged pyridine derivatives 5a-n synthesized starting from 3-cyano-4-trifluoromethyl-6- thiophenyl 2(1H) pyridone 1. Compound 1 on hydrolysis followed by decarboxylation resulted in 4-trifluoro-methyl-6- thiophenyl 2(1H)pyridone 2. Compound 2 treated with POCl3 to get 2- chloro-4-trifluoromethyl-6- thiophenyl pyridine 3 further reaction with hydrazine hydrate, which resulted in the formation of compound 4. Compound 4 on reaction with different substituted 1,3-diketones in ethanol reflux condition to afford pyrazole substituted pyridine derivatives 5a-n. All derivatives were tested against Gram-positive and Gram-negative bacterial strains and different Candida strains by well diffusion method, compounds 5k and 5l showed significant activity. The binding mode of 5k and 5l also studied by molecular docking studies.