Cellulose supported acidic ionic liquid: an efficient and eco-friendly catalyst for the synthesis of quinoxaline derivatives in green media

In recent years, green chemistry has focused mainly on environmentally friendly reactions, sustainable resources and reusable catalysts.Ionic liquids (ILs) have attracted extensive research interest as environmentally benign solvents due to their excellent properties such as negligible vapor pressure, solvating ability and non-flammability1. Compared to pure acidic ILs, IL-based heterogeneous catalysts offer more advantages. They are required in small amounts, areeasy to separateand have a competent catalyst recovery2. The immobilization process aims to transfer the desired catalytic propertiesof the liquids to a solid catalyst.Cellulose is themost abundant renewable bio-macromolecule in the naturewhich is widely produced in industrial scale. It has properties including biodegradability and nontoxicity which make it superior supportfor catalytic applications over conventional organic orinorganic ones. In continuation of our interest to develop environmentally benign synthetic methods in organic chemistry3, we report herein an efficient and green protocolfor the synthesis of substituted quinoxalines using acidic ionic liquid immobilized on cellulose(Cell- [pmim]HSO4) as a catalyst in aqueous media(Figure 1).