Montmorillonite K-10 Supported 11-molybdo-1-vanadophosphoric Acid (H4PMo11V1O40/K-10) Catalysts for Environmentally Benign Synthesis of 2H-indazolo[2,1-b]phthalazine-triones Under Solvent-free Condition

Abstract

A series of 11-molybdo-1-vanadophosphoric acid supported on montmorillonite K-10 catalysts were prepared and characterized by FT-IR spectroscopy, thermal analysis, XRD, BET and SEM analysis techniques. Characterization data reveals the chemical immobilization of H4PMo11V1O40 catalyst on the montmorillonite K-10 support. The catalytic performance of synthesized catalysts was investigated for the synthesis of 2H-indazolo[2,1-b]phthalazine-1,6,11(13H)-trione derivatives by one-pot three-component reaction of phthalhydrazide, dimedone and aromatic aldehydes under solvent-free conditions. Among different catalysts, 20% H4PMo11V1O40 supported on to montmorillonite K-10 showed the highest catalytic activity. Effect of reaction parameters such as catalyst loading, temperature and the nature of substituents on the aromatic ring of aldehydes were also evaluated. The protocol developed using H4PMo11V1O40/K-10 has several distinct advantages such as operational simplicity, short reaction time, high yield, reusable catalyst and preclusion of toxic solvent. DOI: http://dx.doi.org/10.17807/orbital.v9i4.873 </p