Synthetic method of s-metolachlor

Abstract

The invention belongs to the field of herbicides and particularly relates to a synthetic method of s-metolachlor. The synthetic method of s-metolachlor comprises the steps that a cheap compound 2-methyl-6 ethyl benzene easy to obtain is used as a raw material, and finally the high-quality herbicide product s-metolachlor is obtained through condensation reaction, catalytic hydrogenation reduction reaction, chloride acetylation reaction and purification treatment. The simple water-phase s-metolachlor synthesis method easy to execute is provided, the yield of the s-metolachlor product reaches 98.5% and the purity reaches 98.2% in a kilogram-level experiment, and the environment-friendly synthesis method is suitable for industrial production. In addition, compared with a traditional organic solvent synthesis method, use of organic alkali is avoided, few post-treatment steps are adopted, the production pollution is low, the cost is low, required material types are few, the solvent use amount is small, the cost is low, and the method is suitable for large-scale popularization and use.

Description

technical field [0001] The invention belongs to the field of herbicides, in particular to a method for synthesizing refined metolachlor. Background technique [0002] S-metolachlor is a chloroacetamide high-efficiency herbicide developed and promoted by Ciba-Geigy Company, which is now Syngenta. It is a systemic herbicide with high efficiency, low toxicity and high selectivity of organic heterocycles. The product has excellent performance and excellent efficacy, one of the reasons is because of its own chiral structure and the ultra-high-efficiency activity shown by the chiral structural isomer. Due to the difficulty of chiral synthesis of this product, the main market and production supply of this product have been exclusively occupied by Syngenta for a long time. In order to be able to enter and share the production and supply market of this product, the synthetic process route of this herbicide has become a research focus of domestic enterprises and research institution...

AI Technical Summary

Problems solved by technology

The whole process does not need to be split, but the overall yield is unsatisfactory due to the selectivity of acylation, and the cost of industrial production is still high; Many synthetic routes are adopted, mainly using 2,6-methylethylaniline and methoxyacetone as raw materials, after synthesizing imines, asymmetric hydrogenation is carried out under the action of chiral catalysts, and then obtained by acylation reaction For refined metolachlor, the technical difficulty is the synthesis or selection of chiral catalysts. The selection of suitable chiral catalysts is the guarantee of product yield. However, at present, there are situations such as low chiral content and low overall yield. Conducive to the realization of industrial promotion and utilization