Acetic acid functionalized ionic liquid as an environmentally friendly catalyst for the synthesis of spiro[indeno[1,2-b]quinoxaline-11,4-pyran]-2ʹ-amines

Recently, ionic liquids have attracted significant attention as an alternative reaction medium for homogeneous catalysis. Acidic ionic liquids are of special importance because they possess simultaneously proton acidity and the characteristic properties of an ionic liquid [1-2]. The tetrahydrobenzo[b]pyrans are an important calss of the hetrocyclic compunds. these ring systems have long been the subject of numerous studies and successfuly applied as anti-coagulant, diuretic, spasmolytic, anti-cancer, and anti-anaphylactic [3]. Also, these compunds posess the Physical properties and they can be widely applied as photoactive materials [4]. On the other hand, indenoquinoxalines exhibit different pharmacological activity such as anti metabolism and anti tubercular [5].Herein, we have utilized acetic acid functionalized pyridinium salt (1- (carboxymethyl) pyridinium chloride {[cmpy]Cl}) as an efficient catalyst for the preparation of spiro[indeno[1,2-b]quinoxaline-11,4-pyran]-2ʹ- amines(Figure 1).