Ultrasound Assisted Synthesis of Diethyl-2,2?-Thiodiacetate with 2-Bromoethylacetate Under a New Polymer-Supported Phase-Transfer Catalyst in Solid-Liquid Condition

Rajendran V

doi:10.4172/2150-3494.100094

Abstract

In this work, a new polystyrene-bound single-onium phase-transfer catalyst was synthesized, and their catalytic activities were investigated in the synthesis of diethyl-2,2’-thio diacetate derivatives of thioether. The new insoluble polymer anchored mono-site phase-transfer catalyst showed significant high catalytic activity as compared to soluble single site phase-transfer catalysts. The comparative kinetic investigation reveals that the diethyl-2,2’-thio diacetate of ethyl-2-bromoacetate is faster than sodium sulfide in the presence of the new catalyst. This catalyst can be used several times with consistent catalytic activity. Experimental observations support an interfacial-type mechanism.

Highlights

Phase-transfer catalysis (PTC) is a key green approach [1] for driving reactions involving immiscible reactants [2,3,4,5,6]
We decided to synthesize a new monoactive site onium salt with two active sites viz., polymersupported benzyl-N-ethyl-N-di-isopropyl ammonium chloride (PSPTC) by a facile method (Scheme 1).We investigated the catalytic efficiency of the new catalyst by following the comparative kinetics of thioether addition to sodium sulfide and ethyl-2-bromoacetate (EBA) under pseudo-first-order conditions (Scheme 2)
To ascertain the influence of agitation speed on the rate of thioeitherfication of sodium sulfide, the speed of agitation was varied in the range of 0-500 rpm along with ultrasound irradiation (40 kHz, 300 W) using polymer-supported benzyl N-ethyl-N-di-isopropyl ammonium chloride (PSPTC) In principle, the homogeneous reaction is independent of the agitation speed

Summary

Introduction

Phase-transfer catalysis (PTC) is a key green approach [1] for driving reactions involving immiscible reactants [2,3,4,5,6]. Application of this methodology to organic reactions has encountered two major problems viz.: (i) the recovery and reuse of the catalyst and (ii) the separation and purification of the final product [7,8]. The demand and requirement of these triphase catalysts are on the rise due to their popularity

Results

Discussion

Conclusion