Synthesis, antimicrobial, antimycobacterial and structure–activity relationship of substituted pyrazolo-, isoxazolo-, pyrimido- and mercaptopyrimidocyclohepta[b]indoles

Abstract

A new class of heterocycles, specifically substituted pyrazolo-, isoxazolo- and pyrimidocyclohepta[b]indoles, has been prepared by condensation of substituted 7-(hydroxymethylene)-7,8,9,10-tetrahydrocyclohepta[b]indol-6(5H)-ones with hydrazine hydrate, hydroxylamine hydrochloride, phenylhydrazine, urea and thiourea, respectively. The structures of the compounds were established by IR, (1)H NMR, (13)C NMR, mass spectral analysis, X-ray diffraction, and the compounds have been screened for in vitro antimicrobial and antimycobacterial against Mycobacterium tuberculosis H37Rv (MTB). Among the compounds screened, five substances were found to have an MIC of 3.12 μg/ml or greater against MTB. Structure-activity relationship (SAR) analyses and in silico drug relevant properties (HBD, HBA, PSA, c Log P, M.wt) confirmed that the compounds are potential lead compounds for future drug discovery studies.