The article presents a study which investigates the ionic liquid [Et3NSO 3H]Cl as new Brønsted acidic catalyst for the synthesis of N-Sulfonylimines, imidazoles, and methanes. It states that N-sulfonylimines have been a matter of the attention for organic chemists because sufonyl moiety activates the carbon=nitrogen (C=N) bond and hence, these compounds are used as substrates in nucleophilic additions, reactions, and Diels-Alder reactions. It mentions that imidazole derivatives show several pharmacological and biological activities and also are vital factor of lots of biologically active compounds and drugs such as losartan, eprosartan, and trifenagrel. Moreover, Lewis acidic catalysts have been used to effect the condensation of indoles with carbonyl compounds.