N¹,N¹,N²,N²-Tetramethyl-N¹,N²-bis(sulfo)ethane-1,2-diaminium chloride as a highly efficient catalyst for synthesis of some nitrogen- and oxygen-containing heterocyclic compounds

In this research, a Brønsted acidic ionic liquid namely N¹,N¹,N²,N²-tetramethyl-N¹,N²-bis(sulfo)ethane-1,2-diaminium chloride {[TMBSED][Cl]2} was employed as a highly efficient catalyst for the solvent-free production of some nitrogen- and oxygen-containing heterocyclic compounds including: (i) polyhydroquinolines (from arylaldehydes, dimedone, β-ketoesters and ammonium acetate), (ii) 3,4-dihydropyrimidin-2-(1H)-ones/thiones (from arylaldehydes, β-ketoesters and urea/thiourea), and (iii) 14-aryl-14H-dibenzo [a,j]xanthenes (from aromatic aldehydes and β-naphthol). In all cases, the heterocycles were obtained in high yields and in short reaction times.