Preparation of α-hydroxyphenylacetic acid with cyclodextrins as an effective phase-transfer catalyst and its reaction mechanism

Abstract

An effective procedure for the synthesis of α-hydroxyphenylacetic acid with cyclodextrin (CD) catalysts wasdeveloped. The phase-transfer catalyst types, catalyst loadings, reaction times, reaction temperatures, and substratemolar ratios were investigated to optimize the reaction conditions. In addition, the factors that affect the reaction werestudied, and the relationship between benzaldehyde and β -cyclodextrin (β -CD) was analyzed through 2D-ROESY. Theequilibrium constant when β -CD was used as the catalyst was calculated. The results indicated that β -CD is the optimalcatalyst for the reported reaction (yield: 69.08%). Furthermore, the mechanism underlying the reported reaction wasproposed.