Synthesis, spectral analysis and biological screening of some new N-(un)substituted N-(5-chloro-2-methoxyphenyl)-aryl sulfonamides

Abstract

ObjectivesDue to various biological activities of sulfonamides, a series of new N-(5-chloro-2-methoxyphenyl)-aryl sulfonamides (3a–e) and their N-benzyl/ethyl substituted derivatives (6a–e &7a–e) were synthesized followed by antibacterial activity evaluation. MethodsA facile and environmentally benign series of N-(5-chloro-2-methoxyphenyl)-aryl sulfonamide (3a–e) was synthesized in basic aq. medium by coupling of 5-chloro-2-methoxyaniline (1) and various aryl sulfonyl chlorides (2a–e). Further N-benzyl/ethyl substituted derivatives (6a–e &7a–e) were synthesized by stirring 3a–e with the electrophiles 4 &5 at room temperature (RT). The structure elucidation of the synthesized compounds was processed through spectral data. ResultsAll the newer synthesized aryl sulfonamide derivatives were obtained in moderate to good yields in the range of 74–85%. Out of fifteen synthesized derivatives, six compounds 3b, 3c, 3e, 6a, 7d &7e were active against the both bacterial strains of Gram-positive bacteria relative to ciprofloxacin, the reference standard. The significant activity of compound 6a against all bacterial strains might be due to ethyl and ter-butyl groups in the molecule. ConclusionThe synthesized compounds exhibited moderate to good activity against the applied bacterial strains and so the structural changes in the substituents altered the inhibitory properties significantly.