Synthesis of hippuric acid with inverse phase transfer catalyst in a heterogeneous liquid-liquid reaction system

✍ Scribed by S. Asai; H. Nakamura; W. Okada; M. Yamada

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 492 KB
• Volume: 50
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(94)00493-b

✦ Synopsis

The synthesis of hippuric acid from benzoyl chloride and glycine in the presence of 4dimethylaminopyridine as an inverse phase transfer catalyst was carried out in heterogeneous liquid-liquid reaction system using an agitated vessel with a fiat interface. By this synthetic technique, the hippuric acid of high product yield could be obtained without the addition of alkali. The observed overall reaction rates were proportional to the interfacial concentration of salt, 1-benzoyl-4-dimethylaminopyridinium chloride in the aqueous phase, which is formed by the reaction between benzoyl chloride and 4-dimethylaminopyridine in the organic phase. The overall reaction rates could be reasonably explained by the proposed theoretical model for the inverse phase transfer catalysis considering the mass transfer resistance of relevant reaction species. The reaction rate constant evaluated by fitting the rate data to the model prediction was 6.50 m3/(kmol s) at 303 K.