2-(2 ', 2'-difluoro-ethoxy)-6-trifluoromethyl-phenylpropyl sulfur ether synthesis process

Abstract

The present invention discloses a 2-(2 ', 2'-difluoro-ethoxy)-6-trifluoromethyl-phenylpropyl sulfur ether synthesis process. The process is as follows: 2-propyl mercapto-3-trifluoromehtyl phenol, 2,2-difluoroethanol and methanesulfonyl chloride are used as raw materials for two-step reaction to obtain the desired product. The synthesis process uses inexpensive industrial chemicals as the raw materials and reactants for avoiding the use of expensive or highly toxic raw materials, is high in the reaction conversion rate, easy in separation and purification and simple to in process operation, and reduces production costs.

Description

technical field [0001] The invention belongs to the field of fine chemicals, and specifically relates to a synthesis process of 2-(2',2'-difluoroethoxy)-6-trifluoromethylphenylpropyl sulfide. Background technique [0002] Penoxsulam, chemical name 2-(2,2-difluoroethoxy)-N-[5,8-dimethoxy(1,2,4)triazolo-(1,5-C )pyrimidin-2-yl]-6-trifluorotolyl-benzenesulfonamide is a post-emergence herbicide developed by DowAgroSciences in the United States. It is a triazolopyrimidinesulfonamide herbicide. It works by inhibiting acetolactate synthase (ALS). Penoxsulam is a broad-spectrum herbicide for paddy fields, which can effectively control barnyardgrass (including barnyardgrass resistant to propanil, quinclorac and acetyl-CoA carboxylase), annual Cyperaceae weeds , and is effective against many broad-leaved weeds, such as Heterostachys marsh, Carp sausage, Osmanthus japonica, Phyllostachys japonica, Commodityria chinensis, etc. The effective period is as long as 30 to 60 days, and one ...

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Problems solved by technology

In the above synthetic methods, either the starting material 2-fluoro-6-trifluoromethylaniline used is not industrialized and expensive (US20020037811, US5858924, CN103724353), or the introduction of difluoroethoxy is relatively expensive and has no market Chloride 2,2-difluorobromoethane or 2,2-difluoroiodoethane (US20050215570, CN104557800)

Although patent CN102020647 uses relatively cheap and easy-to-obtain 2,2-difluoroethanol when introducing difluoroethoxy, it uses PPh 3 A lot of waste solid PPh will be produced in the post-processing of / DEAD method 3 O, purification is difficult; in addition, the patent CN102001979 uses cheap and commercially available m-trifluoromethyl as the starting material, and uses sulfonyl chloride to protect the phenolic hydroxyl group, and then reacts with butyllithium after forming a sulfonate , but due to the instability of sulfonate in strong alkaline environments such as butyllithium [JACS, 1978, 100, 5525], the hydrogen extraction reaction can only be carried out at ultra-low temperature (-78°C) and the reaction There are many by-products, and it is difficult to achieve industrial scale-up

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