Nano-silica supported acidic ionic liquid as an efficient catalyst for the multi-component synthesis of indazolophthalazine-triones and bis-indazolophthalazine-triones

A supported ionic liquid bearing sulfonic acid groups was synthesized by anchoring 3-sulfopropyl-1-(3-propyltrimethoxysilane)imidazolium hydrogen sulfate onto nano-silica and characterized by FT-IR spectroscopy, elemental analysis and scanning electron microscopy (SEM) techniques. This catalyst was used for the efficient one-pot multi-component synthesis of indazolophthalazine-triones and bisindazolophthalazine-triones. Moreover, the catalyst could be reused at least seven times without any significant loss of activity.