SYNTHESIS AND ANTITUBERCULAR EVALUATION OF CERTAIN PYRROLE DERIVATIVES

A series of 2-aryl-5-[4-(1H-pyrrol-1-yl)phenyl]-1,3,4-oxadiazole derivatives (VIa-g) have been synthesized in good yields. These compounds were synthesized with an approach to reduce the growing anti-tubercular resistance and to develop more potent and less side effects having antitubercular activity. The reaction of 2,5-dimethoxytetrahydro furan with 4-aminobenzoate (II) in presence of ethanol, which yields ethyl 4-pyrrol-1-yl benzoate (III). This ethyl-4-pyrrol-1-yl benzoate (III) on reaction with hydrazine hydrate produced 4-pyrrol-1-yl benzoic acid hydrazide (IV). This carbohydrazide on treatment with different substituted benzoyl chlorides gave intermediates (Va-g), which on cyclisation with P₂O₅ in the presence of DMF yielded of 2-aryl-5-[4-(1Hpyrrol-1-yl)phenyl]-1,3,4-oxadiazoles VI(a-g). Structure of newly synthesized pyrrole derivatives were confirmed on the basis of physicochemical and spectral data (IR, ¹H-NMR, ¹³C-NMR and Mass spectra). All the synthesized compounds were screened for their antitubercular activity using Microplate Alamar Blue Assay (MABA) method. Compounds showed anti-tubercular activity at MIC values between 1.6 to 12.5 µg/ml, compounds VIb,VIc and VId showed highest activity of 1.6 µg/ml. Selected compounds were evaluated for anti-bacterial activity against gram positive (S. aureus) and gram negative (E. coli). Compounds showed moderate activity. Physicochemical properties of the selected compounds satisfieds with the Lipinski’s rule of 5.