Synthesis, characterization and application of ionic liquid 1,3-disulfonic acid imidazolium hydrogen sulfate as an efficient catalyst for the preparation of hexahydroquinolines

► Introducing a novel ionic liquid (IL) as catalyst for organic transformations ► Characterization of the IL using FT-IR, 1H and 13C NMR, mass, TG, DTG and XRD spectra ► Studying the efficiency of the IL to catalyze hexahydroquinoline synthesis ► Generality of the catalyst, high yields and short reaction times