Synthesis and characterization of new N-(4-(4-chloro-1H-imidazol-1-yl)-3-methoxyphenyl)amide/sulfonamide derivatives as possible antimicrobial and antitubercular agents

Abstract

In this paper we report the SAR studies of a series of N-(4-(4-chloro-1H-imidazol-1-yl)-3-methoxyphenyl)amide and N-(4-(4-chloro-1H-imidazol-1-yl)-3-methoxyphenyl)sulfonamide derivatives 6(a-o) and 7(a-o), were synthesized in good yields and characterized by (1)H NMR, (13)C NMR and mass spectral analyses. The preparation of the key intermediate highlights an optimized palladium catalyzed (Pd₂(dba)₃/RuPhos) Buchwald cross-coupling of intermediate 2 and 3. The newly synthesized compounds were evaluated for their in vitro antibacterial activity against Staphylococcus aureus, (Gram-positive), Escherichia coli and Klebsiella pneumoniae (Gram-negative), antifungal activity against Candida albicans, Aspergillus flavus and Rhizopus sp. and antitubercular activity against Mycobacterium tuberculosis H37Rv, Mycobacterium smegmatis, Mycobacterium fortuitum and MDR-TB strains. The synthesized compounds displayed interesting antimicrobial activity. The compounds 7d, 7f, 7h and 7n displayed significant activity against Mycobacterium tuberculosis H37Rv strain.

Keywords: Antimicrobial activity; Antimycobacterial activity; Imidazole; Pd(2)(dba)(3); RuPhos.