Effect of Reaction Conditions on the Conversion and Selectivity of MCM-41 and Al-20-MCM-41 Catalyzed Amine Coupling Reactions

Abstract

The study has been performed to examine the effect of different reaction conditions (presence of a solvent, absence of solvent, presence of air and closed vessel with an absence of air) on the conversion and selectivity of oxidative coupling reactions of amines to imines using MCM-41 and Al-20-MCM- 41 catalysts. Two types of coupling reactions were discussed viz. self-coupling and cross coupling. Self-coupling reaction was observed to be faster with Al-20-MCM-41 than MCM-41, while the cross-coupling reactions with Al-20-MCM-41 was slightly slower than MCM-41. The conversion and selectivity of self and cross coupling reactions in different reaction conditions were also investigated. The reaction was found to be of shifting order, initially first order when amine concentration was high and tending towards zero at lower amine concentration. It was evident that both catalysts Al-20-MCM-41 and MCM-41 showed a good catalytic activity on the oxidative coupling reactions of amine but somewhat higher conversion was obtained with Al-20-MCM-41 because of presence of acidic site.