The Study On The Asymmetric Synthesis Of (S)-Metolachlor

The Chirality is one of the essential attribute of nature, in particular, plays a particularly important role in the life science and technology. With the development of economy and society, people havemore understanding of the natural phenomenon,and the demand for chiral substances is also increasing, which promote the vigorous development of the synthesis of optical pure products.Asymmetric catalysis is one of the ways to synthesize chiral compounds which has several advantages such as chiral proliferation, high enantioselectivity and easy industrial production, so it is the most promising method for synthesis.In2001, in order to celebrate their outstanding contributions in asymmetric oxidation and asymmetric hydrogenation, chemists Sharpless and Knowles, Noyori won that year's Nobel Prize in Chemistry, which showed that the research in asymmetric synthesis has made significant progress and get more attention of the world.(S)-Metolachlor is a highly selective herbicides,which is the one of the most important herbicide for many crops such as corn, cotton, and so on.The research about synthesis of (S)-Metolachlor has been the focus of the pharmaceutical industry all over the world. People have always been looking for a directly industrial method to prepare (S)-Metolachlor, which is simple, safe and low cost,so it can decrease consumption, reduce production costs and benefit human. Now the (S)-Metolachlor used in China is mainly imported from abroad and combinated before use it, so the potential market is considerable.Given its importance, its synthetic process was studied in this thesis.The2methyl-6-ethylaniline was used as starting material to synthesize1-methoxy propyl-2-(2-methyl-6-Ethyl phenyl) imide through condensating with methoxy-propane, The high enantioselective1-methoxy-propyl-2-(2-methyl-6-ethyl-phenyl) amine was obtained by the asymmetric hydrogenation of1methoxy-propyl-2-(2-methyl-6-ethyl-phenyl) imine by a effective catalyst, and then after a chlorine acetylation, the target compound (S)-metolachlor was obtained. At the same time,we also the optimize the reaction conditions of whole process,which the optimistic reaction condition were foud.The results show that the line method is simple and low cost, and have a high conversion rate. The content of the target product is up to98%by the analysis of gas chromatography, so its a good method to synthesize (S)-Metolachlor with considerable industrial prospect.The discovery and development of Asymmetric catalysis is one of the important achievements in the field of chemical industry and the whole Natural science in the20th century. In2001, as to the outstanding contribution in asymmetric hydrogenation and asymmetric oxidation, three chemists, Knowles, Noyori and Sharpless, won that year's Nobel Prize in Chemistry, which showed that the research has made significant progress.