Ultrasonically Promoted Synthesis of Ethyl 2-(naphthalen-2-yloxy)acetate in Solid-Liquid Heterogeneous Phase Transfer Catalysis Condition

Abstract

In this paper, the synthesis of ethyl 2-(naphthalen-2-yloxy)acetate from β-naphthol and ethyl 2-bromoacetate under ultrasound and catalyzed by quaternary ammonium salt in solid-liquid heterogeneous condition was described. Trace amount of water play a major role in this solid-liquid reaction. The reaction follows pseudo first order rate law. The apparent rate constant of the organic phase reaction was obtained form the experimental data. The combination of small amount of tetrabutylammonium bromide (TBAB) and ultrasound (kapp = 25.22×10 -3 min -1 ) shows several fold enhanced rate of the reaction than the conventional operation (kapp = 6.42×10 -3 min -1 for TBAB only). The rate constant increases (0.05 to 0.3 g) with increase in the concentration of catalyst (from kapp = 10.12×10 -3 min -1 to kapp = 34.46×10 -3 min -1 ). The other kinetic effects such as, effect of agitation speed, kind of frequency of ultrasound, kind of various quantity of K2CO3, quantity of water, temperature, different quaternary ammonium salts, solvents and volume of organic solvents on the conversion of ethyl 2-bromoacetate and apparent rate constant were investigated in detail and rational explanations are provided.