Green approach towards synthesis of substituted pyrazole-1,4-dihydro,9-oxa,1,2,6,8-tetrazacyclopentano[b]naphthalene-5-one derivatives as antimycobacterial agents

Abstract

In the present communication, a simple and efficient synthesis of some new Pyrano-[2,3-c]-pyrazoles derivatives are described by the one-pot condensation of a mixture of 3-methyl-1-phenyl-1H-pyrazole-5(4H)-one, substituted heterylaldehydes and malononitriles in polyethylene glycol (PEG-400) as green reaction solvent, further reacted with substituted acetophenones in the presence of polyethylene glycol (PEG-400) to form naphthalene analogues. Synthesis of novel substituted naphthalene analogues libraries are currently of high interest. The chemical structures of newly synthesized compounds were confirmed by IR, 1H NMR and Mass spectral analysis. In vitro antimycobacterial activities of newly synthesized compounds were investigated against Mycobacterium smegmatis, Mycobacterium pheli and Mycobacterium tuberculosis species. The result revealed that most of the compounds showed good to moderate Antimycobacterial activity.