P-Toluene sulfonic acid (PTSA)-MCM-41 as a green, efficient and reusable heterogeneous catalyst for the synthesis of jasminaldehyde under solvent-free condition

Abstract

This paper reports the synthesis of p-Toluene sulfonic acid (PTSA)-MCM-41 by impregnation method and its characterization XRD, FT-IR, TGA, N2 adsorption–desorption isotherms, SEM, and TEM. The impregnated catalysts were used to catalyse cross-aldol condensation of active methylene bearing aliphatic aldehydes with aromatic aldehydes under solvent and metal-free condition particularly in the synthesis perfumery chemical-jasminaldehyde and related compounds. The as synthesized catalyst PTSA-MCM-41 has displayed high efficiency (selectivity up to 91%) in catalyzing cross-aldol condensation reaction and was reusable (5 cycles) with no apparent loss in activity. The catalytic performance of PTSA-MCM-41 was compared with other catalysts viz., ZnO, proline, proline-LDH, PTSA, PTSA-zirconia and PTSA-zeolite where PTSA-MCM-41 showed better performance particularly in synthesis of jasminaldehyde.