Introduction of a new dicationic ionic liquid deployed on cross-linked chitosan as a sustainable catalyst for the synthesis of some spiro-oxindoles and spiro-quinazolines

In this study 1,4-bis(4-chlorobutyl)piperazine-1,4-diium hydrogen sulfate deployed on Chitosan (Ch-IL-HSO4 ) was prepared through a simple approach and different demonstrative techniques including FT-IR, TGA, EDS, XRD, FESEM, 1HNMR and 13CNMR were used for its identification. Bio-polymer structure of Chitosan and its basic and hydrophilic parts make it to be an attractive support for immobilization of the candidate IL to increase its catalytic activity. After these studies, the promoting ability of this catalyst was investigated in the highly efficient synthesis of spiro-oxindoles and spiro-quinazolines as two important organic compounds with high biological activities which need novel and robust catalyst to accelerate their synthesis. Ease of the preparation, separation and reuse of Ch-IL-HSO4 , short reaction times and excellent yields of the obtained compounds are among the prominent features of the presented protocol.

Automated summary

1,4-bis(4-chlorobutyl)piperazine-1,4-diium hydrogen sulfate was successfully prepared on the Chitosan support, and various techniques were used to identify the obtained compound. The Chitosan structure and its hydrophilic properties make it an attractive support for immobilization, increasing the catalytic activity of the catalyst.