Synthesis method of 3-chloropropionyl chloride

Abstract

The invention discloses a synthesis method of 3-chloropropionyl chloride, and relates to the technical field of chemical engineering, which comprises the following steps: adding acrylic acid, a catalyst and water into a reactor, and conducting stirring; dropwise adding thionyl chloride under stirring while keeping the temperature at 20-80 DEG C; after dropwise adding thionyl chloride, conducting stirring for 0.5-2 hour at the temperature of 20-80 DEG C to obtain a crude product of 3-chloropropionyl chloride; and carrying out reduced pressure distillation on the crude product of 3-chloropropionyl chloride to obtain high-purity 3-chloropropionyl chloride. By adding the catalyst and water, the water and thionyl chloride generate extra sufficient hydrogen chloride in the reaction to make up for the loss of hydrogen chloride in the system, and the hydrogen chloride fully reacts with acrylic acid and acryloyl chloride under the action of the catalyst to generate 3-chloropropionic acid and 3-chloropropionyl chloride. The synthetic method has the advantages of simple process, less investment equipment, high equipment efficiency, easily available raw materials, low price and less generatedthree wastes, and the final purposes of high yield and high product content are achieved according to the synthetic method.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a method for synthesizing 3-chloropropionyl chloride. Background technique [0002] 3-Chloropropionyl chloride is mainly used in organic synthesis fields such as medicine and pesticide. There are three main technologies currently used in industry: [0003] 1. One-step method: react acrylic acid with thionyl chloride to directly synthesize 3-chloropropionyl chloride. Typical technologies include JP Ping 11-199540 (Yokota Keiichi, etc.), CN103819329B (Xu Xiaohu) and CN109534988A (Wang Xi, Wang Qiang). [0004] JP flat 11-199540 adopts acrylic acid, catalyzer, sulfur oxychloride reaction, contains a large amount of acryloyl chlorides in the crude product, and main product selectivity is low, and product is difficult to separate, and yield is low; The purification process of product is not mentioned. The chemical reaction equation is: [0005] [0006] [0007] CN...

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Problems solved by technology

[0007] CN103819329B adopts acrylic acid and water to mix, drips thionyl chloride to react, since no catalyst is added, according to the amount of water and thionyl chloride described in the patent, a small amount of acryloyl chloride will still be produced in the reaction, and the product yield still cannot make people are satisfied

[0012] CN109534988A adopts acrylic acid, thionyl chloride, aluminum oxide powder, zene, yttrium oxide, sodium polyacrylate, aluminum oxide matrix, ionic liquid [bmim]Cl-AlCl Under the catalyst effect, react to obtain 3-chloropropionyl chloride, the method used The catalyst production process is complicated and the conditions are harsh, so it is not suitable for large-scale industrial production

The problem that this method exists: the first, adopt 3-chloropropionic acid as starting raw material, 3-chloropropionic acid needs to be synthesized or purchased, has increased cost additionally; The 2nd, thionyl chloride reacts with 3-chloropropionic acid to produce A large amount of mixed gas of sulfur dioxide and hydrogen chloride is not easy to handle; the 3rd, the reaction yield is still unsatisfactory, when the mol ratio of thionyl chloride and 3-chloropropionic acid is 1.2:1, yield is less than 85%; When the molar ratio of sulfoxide and 3-chloropropionic acid is 5.0:1, the yield just reaches 90.8%. Such a feed ratio reduces equipment efficiency and increases post-processing difficulty simultaneously

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