Preparation method and application of clethodim intermediate

Abstract

The invention discloses a preparation method and application of a clethodim intermediate. The preparation method of the clethodim intermediate comprises the step of directly reacting a compound A withpropionyl chloride or propionic anhydride under the action of a catalyst to prepare a compound D, wherein the catalyst is a ZSM-5 molecular sieve or / and an H-ZSM-5 molecular sieve. A special catalystis selected, the compound D is prepared from the compound A in one step, operation is easy and convenient, catalyst selectivity is high, side reactions are few, the reaction process is easy to control, participation of water is not needed in the reaction process, a large amount of water cannot be introduced, and therefore hydrolysis side reactions cannot happen, the byproduct content is further reduced, and the product purity is improved. The reaction does not need intermediate washing, layering, rearrangement and other operations, thereby simplifying the process flow, shortening the reactiontime and enhancing the production efficiency. The yield of the compound D is high and is 87% or above, and the purity is high and is 85% or above.

Description

technical field [0001] The present invention relates to a preparation method of clethodim intermediate, in particular to a preparation method of clethodim intermediate with simple process and few side reactions, and also to a method for preparing clethodim by using the intermediate, belonging to clethodim Ketone preparation technical field. Background technique [0002] Clethodim, the chemical name is 2-{1-[(3-chloro-2-allyl)oxy]iminopropyl}-5-[2-(ethylthio)propyl]-3-hydroxy -2-Cyclohexen-1-one is a broad-spectrum post-emergence herbicide for controlling grass weeds in broadleaf crops. It has a strong killing effect on annual and perennial grass weeds, and is mainly suitable for soybeans It can control more than 40 kinds of crops such as cotton, peanut, watermelon and more than 30 kinds of gramineous weeds such as barnyard grass. [0003] At present, there are few reports on the synthetic routes of clethodim, and the yields are not high. In 2001, the patent US6300281 repo...

AI Technical Summary

Problems solved by technology

The compound Ⅵ is the same substance as the compound Ⅴ in US6300281. In this process, the synthesis of the compound Ⅵ from the compound Ⅳ has long and cumbersome process steps. Although the amine catalyst can improve the rearrangement selectivity, the improvement is limited, and the reaction still produces relatively high There are many by-product impurities, and the impurities will be converted into tar in the subsequent hydrolysis rearrangement, which affects the yield and product quality. The yield of compound VI is about 80% according to its report

Furthermore, the use of amine catalysts leads to high ammonia nitrogen content in wastewater, requiring special removal of ammonia nitrogen, which increases the burden of wastewater treatment

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