Design, synthesis, characterization, and catalytic properties of g-C3N4-SO3H as an efficient nanosheet ionic liquid for one-pot synthesis of pyrazolo[3,4-b]pyridines and bis(indolyl)methanes

A novel sulfonic-functionalized ionic liquid, C3N4 (C3N4-SO3H (IL)), was prepared and its structure was characterized using FTIR, TEM. XRD, CH NS elemental analysis and FESEM-EDX mapping. Catalytic activity of the liquid was studied for the syntheses of pyrazolo[3,4-b]pyridine and bis(indolyl)methane derivatives under moderate conditions. The catalyst was demonstrated to be reused at least 5 runs without considerable decrease in its activity. Some of the important advantages of the methodology were proved to be good yields, easy work-up, short reaction time and broad scope of substrates. (C) 2020 Elsevier B.V. All rights reserved.