Continuous synthetic method for 3,5-dichloro-2-pentanone

Abstract

The invention discloses a continuous synthetic method for 3,5-dichloro-2-pentanone. The method comprises the steps of adding a dichloroethane solution of alpha-chloro-alpha-acetyl-gamma-butyrolactone and carbonyl chloride into a microreactor, and conducting continuous chlorination ring-opening reaction to generate 3,5-dichloro-2-pentanone. The continuous synthetic method for 3,5-dichloro-2-pentanone has the advantages of no catalyst, simplicity in operation, high reaction selectivity, low energy consumption, high purity, high yield and the like.

Description

technical field [0001] The invention belongs to the technical field of preparation of fine chemical products, and in particular relates to a continuous synthesis method of 3,5-dichloro-2-pentanone. Background technique [0002] 3,5-dichloro-2-pentanone, English name: 3,5-dichloro-2-pentanone, molecular formula: C 5 h 8 Cl 2 O, molecular weight: 155, molecular structure formula: [0003] [0004] 3,5-Dichloro-2-pentanone is an important pharmaceutical and pesticide intermediate, which can be used to synthesize γ-aminobutyric acid (GABA) modulator clomethiazole, and can also be used to synthesize a series of medical compounds for inhibiting leukemia and anti-tumor , or an important intermediate of triazole fungicide prothioconazole. Prothioconazole is a new type of broad-spectrum triazolethione fungicide developed by Bayer, mainly used to prevent and control many diseases of cereals, wheat and legumes. Prothioconazole has low toxicity, no teratogenicity, and no mutageni...

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Problems solved by technology

[0005] In 2014, Qin Yongqi and others disclosed a method for synthesizing 3,5-dichloro-2-pentanone using γ-butyrolactone and sulfonyl chloride as main raw materials, methanol, thionyl chloride, dioxane, concentrated hydrochloric acid, etc.; The method is cumbersome in operation, long in process, numerous in raw materials, and the specific yield content has not been reported.

[0006] In 2015, Li Yu and others disclosed a method for synthesizing 3,5-dichloro-2-pentanone with α-chloro-α-acetyl-γ-butyrolactone, glacial acetic acid and concentrated hydrochloric acid as main raw materials; The specific content of 3,5-dichloro-2-pentanone has not been reported, and its yield is 88.5%. The operation process of this method is relatively simple, but the consumption of glacial acetic acid and concentrated hydrochloric acid is large, the recovery is difficult, the amount of waste acid is large, and the three wastes large

[0007] Chen Mingming et al. reported in 2015 a batch synthesis of 3,5-dichloro-2-pentane with α-chloro-α-acetyl-γ-butyrolactone and solid phosgene as main raw materials under the catalytic action of a catalyst. The method of ketone; the operation of this method is more loaded down with trivial details, and reaction needs to add catalyst, and belongs to intermittent reaction, and yield is not high

[0008] In 2015, Zhang Yu and others disclosed a method to synthesize 3,5-dichloro-2-butyrolactone by reaction and distillation using α-chloro-α-acetyl-γ-butyrolactone, salt, phase transfer catalyst and concentrated hydrochloric acid as the main raw materials. The method of pentanone; the method is cumbersome to operate, the reaction time is long, the reaction of some raw materials is not complete, the amount of three wastes is large, and the operating environment is poor

[0009] The synthesis method of this similar compound reported at present is mainly a batch method, method one: the sulfuryl chloride method, this method has the following disadvantages: the operation process is loaded down with trivial details, the flow process is long, involves many raw materials, and the amount of three wastes is large

Method 2: Concentrated hydrochloric acid method, this method has the following disadvantages: the use of glacial acetic acid and concentrated hydrochloric acid is large, recovery is difficult, the amount of waste acid is large, and the amount of three wastes is large

Method three: solid phosgene method, this method has the following disadvantages: the operation is cumbersome, a catalyst must be involved in the reaction, it is an intermittent reaction, the yield is not high, and the amount of three wastes is large

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