Acidic ionic liquid immobilized on cellulose: an efficient and recyclable heterogeneous catalyst for the solvent-free synthesis of hydroxylated trisubstituted pyridines†
The synthesis of a novel cellulose supported acidic ionic liquid (Cell-IL) for the solvent-free synthesis of hydroxylated trisubstituted pyridines is reported. Cell-IL was prepared by immobilization of an acidic ionic liquid [1-butyl-3-(3-trimethoxypropyl)-1H-imidazol-3-ium hydrogen sulfate] on cellulose. The viability of this concept has been confirmed by FT-IR, TGA-DTG, 1H NMR and elemental analysis. The Cell-IL showed good thermal stability and exhibited a high catalytic activity in the synthesis of a series of hydroxylated trisubstituted pyridines. It was recovered and reused for the model reaction three times without an appreciable change in its activity.