关键词:

含氨高温液态水, 苯乙腈, 苯乙酰胺, 苯乙酸, 反应动力学

Abstract:

In order to solve the problem of slow reaction rate for non-catalyzed hydrolysis of phenylacetonitrile in high temperature liquid water (HTLW), a new method was proposed to accelerate the reaction by the addition of NH₃ to the HTLW.Hydrolysis reaction kinetics of phenylacetonitrile and phenylacetamide as its intermediate at different temperatures and ammonia concentrations was determined.From the reaction kinetics data of phenylacetonitrile hydrolysis, the yield of phenylacetamide increased from 26.9% without addition of ammonia to 50.8% at the ammonia concentration of 919.4 mg·L^-1.From the reaction kinetics analysis, the addition of ammonia could greatly promote the reaction rate of phenylacetonitrile hydrolysis to phenylacetamide, but have relatively small impact on the hydrolysis of phenylacetamide to phenylacetic acid, indicating possibly a higher yield of phenylacetamide.For non-catalyzed hydrolysis of phenylacetonitrile in HTLW, the reaction kinetics data were in good agreement with the first order reaction kinetic equation, but second order reaction kinetic equation fitted the data well for phenylacetonitrile hydrolysis in NH₃-enriched HTLW.At the ammonia concentration of 229.8 mg·L^-1, the activation energies for phenylacetonitrile and phenylacetamide hydrolysis lowered to 57.2 kJ·mol^-1 and 67.7 kJ·mol^-1, respectively.All these data gave hints that the addition of ammonia to HTLW may change the pathway of phenylacetonitrile hydrolysis.This work will not only provide basic data for environmentally benign preparation of phenylacetamide and phenylacetic acid, but also improve the applicability of organic synthesis in HTLW.

Key words:

含氨高温液态水, 苯乙腈, 苯乙酰胺, 苯乙酸, 反应动力学