An efficient route to the one-pot synthesis of 1H-indazolo[2,1-b]-Phthalazinetrione catalyzed by β -Cyclodextrin sulfunic acid supported on nano rice husk silica

The synthesis of new heterocyclic compounds has always been a subject of great interest due to their wide applicability. Among a large variety of heterocyclic compounds, heterocycles containing phthalazine moiety are of interest because they show several pharmacological and biological activities. Phthalazine derivatives, which have two bridgehead nitrogen atoms in a fused ring system, possess cytotoxic, antimicrobial, anticonvulsant, antifungal, anticancer and anti-inflammatory activities. Moreover, these compounds exhibited good promise as new luminescent materials or fluorescence probes.1,2 By having these facts in minds, in this research β _cyclodextrin sulfunic acid was easily prepared by the reaction of β _cyclidextrin and chloro sulfunic acid in dry chloroform (CHCl3) at room temprature, and to modified its efficiency, supported on nano silica. nano silica extracted from rice husk by acid treatment and then combustion.The size of nano silica was determined by SEM microscopy.The capacity of solid acid was determined by acid_base titration. The catalitic ability of this acid in the three components condensation reaction of a varity of a aromatic aldehyde with electron donating and electron with drawing groups with phethalhydrazide and dimidone was investigated. According to the results, this solid acid act very efficient and produced 1H_indazolo [2,1-b]-Phthalazinetrione derivatives in good isolated yields in short reaction time.