Cellulose sulfuric acid as a new, biodegradable and environmentally friendly biopolymer for synthesis of 4,4'-(arylmethylene)bis(3-methyl-1-phenyl- 1H-pyrazol-5-ols)

Abstract

The one-pot multicomponent synthesis of 4,4'-arylmethylene-bis(3-methyl-1- phenyl-1H-pyrazol-5-ol) was performed effectively by tandem Knoevenagel-Michael reaction of aryl aldehydes and 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one in the presence of a catalytic amount of cellulose sulfuric acid as an environmentally friendly biopolymer-based solid acid catalyst at reflux conditions. All of obtained compounds were characterized by FT IR, 1H and 13C NMR. This new methodology is of interest due to minimizing the cost operational hazards and environmental pollution, high yields, short reaction time, cost effective and simple work-up.