Lipase-catalyzed dynamic kinetic resolution of (R,S)-naproxen ester in isooctane

• Main Authors: Han-Yuan Lin, 林瀚淵
• Other Authors: Shau-Wei Tsai
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/3mmmnm

碩士 === 國立成功大學 === 化學工程學系碩博士班 === 90 === Lipase MY has been successfully employed as the biocatalyst with excellent enantioselectivity and activity in the kinetic resolution of racemic naproxen trifluoroethyl ester via hydrolysis. Besides, a dynamic kinetic resolution process for the lipase-catalyzed hydrolysis of racemic naproxen trifluoroethyl thioester has also been developed by using Lipase MY and trioctylamine as the biocatalyst and racemization catalyst, respectively. Therefore, the purpose of this research is aimed to develop a dynamic kinetic resolution process with (R,S)-naproxen trifluoroethyl ester as the substrate. Stronger organic bases were firstly screened to effectively racemize the substrate. A linear relationship between the interconversion constant and the base concentration was found. However, the stronger was the base in racemization, the higher of hydrolysis of the base was observed. Since the base might deactivate the enzyme, a polymer-supported base was replaced as the racemization catalyst in the dynamic kinetic resolution process. The maximum 50% yield of the desired optical product in the standard kinetic resolution process was overcome. Agreements between the experimental data and theoretical results were found in which an enzymatic Michaelis-Menten kinetics, lipase deactivation and inhibition and a first-order reversible racemization kinetics were employed in the theoretical modelling.