Synthesis of a novel class of some biquinoline pyridine hybrids via one-pot, three-component reaction and their antimicrobial activity

Abstract

A small library of novel class of biquinoline containing pyridine moiety were synthesized by a one-pot cyclocondensation of 2-chloro-3-formyl quinoline, active methylene compounds and 3-(pyridine-3-ylamino)cyclohex-2-enone in the presence of catalytic amount of sodium hydroxide. The protocol offers rapid synthesis of structurally diverse novel class of some biquinoline pyridine hybrids for antimicrobial screening. These compounds were screened for their antibacterial activity against Gram-positive bacteria (Bacillus subtilis, Clostridium tetani, Streptococcus pneumoniae), Gram-negative bacteria (Escherichia coli, Salmonella typhi, Vibrio cholerae) and antifungal activity against Aspergillus fumigatus, Candida albicans. Some of the biquinoline compounds were found to be more potent or equipotent than the first line standard drugs. The compounds were evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv strain using Lowenstein–Jensen medium. Compound 4g showed a compelling activity at 6.25 μg/mL with a 96% inhibition and could be ideally suited for further modifications to obtain more efficacious compounds in the fight against tuberculosis. A small library of novel class of biquinoline containing pyridine moiety were synthesized by a one-pot cyclocondensation of 2-chloro-3-formyl quinoline, active methylene compounds and 3-(pyridine-3-ylamino)cyclohex-2-enone in the presence of catalytic amount of NaOH. These compounds were screened for their antimicrobial and antimycobacterial activity.