A chemoenzymatic approach for the production of (S)-metolachlor, one of the most widely used herbicides, has been developed. The starting material (S)-N-(2-ethyl-6-methylphenyl)alanine was obtained by the use of lipase-catalyzed hydrolytic kinetic resolution. Under the optimal conditions, the good activity and excellent enantioselectivity of lipase B from Candida antarctica (CAL-B,E > 100) are achieved in diethyl ether – water (15% v/v), which is about 9.7-fold more enantioselective than that in a pure buffered aqueous solution (E = 12.1). After a simple extraction procedure is used to separate the acid product from the remaining ester, the remaining ester is racemized, providing the basis for the continuous resolution process. Then (S)-metolachlor is synthesized by a simple chemical method using the enantiomerically pure (S)-acid.Key words: (S)-metolachlor, herbicide, CAL-B, (S)-N-(2-ethyl-6-methylphenyl)alanine, resolution.
我们开发出了一种化学酶法生产(S)-甲草胺(最广泛使用的除草剂之一)的方法。起始原料(S)-N-(2-乙基-6-甲基苯基)丙氨酸是通过脂肪酶催化的水解动力学解析获得的。在最佳条件下,在二乙醚-水(15% v/v)中,来自南极念珠菌的脂肪酶 B(CAL-B,E >100)具有良好的活性和出色的对映选择性,其对映选择性比在纯缓冲水溶液(E = 12.1)中高出约 9.7 倍。使用简单的萃取程序将酸产物与剩余的酯分离后,剩余的酯发生消旋化,为连续解析过程奠定了基础。然后,利用对映体纯的(S)-酸,通过简单的化学方法合成了(S)-甲草胺。 关键词:(S)-甲草胺 除草剂 CAL-B (S)-N-(2-ethyl-6-methylphenyl)alanine 解析。