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

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 H 4 PMo 11 V 1 O 40 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% H 4 PMo 11 V 1 O 40 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 H 4 PMo 11 V 1 O 40 /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