Microwave-Assisted Synthesis of Some Indole and IsoniazidDerivatives as Antitubercular Agents and Molecular Docking Study

An efficient and expeditious microwave-assisted synthesis of isoniazid derivatives from various indole-3-carbaldehydes, phenols, and isoniazid via Betti’s reaction under one pot, solvent-free, and green reaction conditions is described. The same compounds were also prepared by conventional method. Relatively short reaction time and good yields make the proposed protocol highly significant. The structures of the newly synthesized compounds were confirmed by spectral and analytical data. The synthesized compounds were evaluated for their potential in vitro antitubercular activity against M. tuberculosis H37Rv strain using Alamar Blue assay. Some of the tested compounds were found to be highly active against M. tuberculosis H37Rv with minimum inhibitory concentrations of 3.12, 6.25, and 12.5 µg/mL, while the others showed a moderate activity. Docking of the potent compounds inside the active site of the target enzyme mycobacterial enoyl reductase (InhA) (FabI ENR, PDB code 4TZK) was performed in order to interpret the results.