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CN-121974775-A - Synthetic method of chloromethyl styrene

CN121974775ACN 121974775 ACN121974775 ACN 121974775ACN-121974775-A

Abstract

The invention relates to a method for synthesizing chloromethyl styrene, which comprises the following steps of (1) carrying out selective reduction reaction on terephthalaldehyde or isophthalaldehyde in the presence of a reducing agent to obtain p-hydroxy methyl benzaldehyde or 3- (hydroxymethyl) benzaldehyde, (2) carrying out chlorination reaction on the p-hydroxy methyl benzaldehyde or 3- (hydroxymethyl) benzaldehyde obtained in the step (1) in the presence of a chlorinating agent to obtain p-chloromethyl benzaldehyde or 3- (chloromethyl) benzaldehyde, and (3) carrying out Wittig reaction on the p-chloromethyl benzaldehyde or 3- (chloromethyl) benzaldehyde obtained in the step (2) in the presence of alkali to generate p-chloromethyl styrene or m-chloromethyl styrene. The method avoids using highly toxic chlorine or an intermediate difficult to synthesize, has the advantages of short steps, mild conditions, high selectivity, high yield, environmental friendliness and the like, and has good industrial application prospect.

Inventors

  • Ye Haishun
  • CHEN LEI
  • LIU FENG
  • PAN ZHIJUN

Assignees

  • 浙江鼎龙科技股份有限公司
  • 内蒙古鼎利科技有限公司

Dates

Publication Date
20260505
Application Date
20260408

Claims (10)

  1. 1. The synthesis method of chloromethyl styrene is characterized by comprising the following steps: (1) In the presence of a reducing agent, carrying out selective reduction reaction on terephthalaldehyde or isophthalaldehyde, reducing one aldehyde group into hydroxymethyl, and retaining the other aldehyde group to obtain p-hydroxymethyl benzaldehyde or 3- (hydroxymethyl) benzaldehyde; (2) In the presence of a chlorinating agent, carrying out chlorination reaction on the p-hydroxy-methyl benzaldehyde or 3- (hydroxymethyl) benzaldehyde obtained in the step (1) to obtain p-chloromethyl benzaldehyde or 3- (chloromethyl) benzaldehyde; (3) And (3) carrying out Wittig reaction on the p-chloromethylbenzaldehyde or 3- (chloromethyl) benzaldehyde obtained in the step (2) in the presence of alkali to generate p-chloromethyl styrene or m-chloromethyl styrene.
  2. 2. The method for synthesizing chloromethylstyrene according to claim 1, wherein in step (1), the reducing agent is one selected from the group consisting of sodium borohydride, sodium cyanoborohydride, sodium triacetoxyborohydride, lithium aluminum hydride, sodium borohydride/cerium trichloride heptahydrate.
  3. 3. The method for synthesizing chloromethyl styrene according to claim 1, wherein in the step (1), the selective reduction reaction is performed in an alcohol solvent, and the amount of the reducing agent is 0.2 to 0.3 equivalent of the benzene dicarboxaldehyde.
  4. 4. The method for synthesizing chloromethyl styrene according to claim 3, wherein the selective reduction reaction temperature is controlled at-10 ℃ to 40 ℃.
  5. 5. The method for synthesizing chloromethylstyrene according to claim 1, wherein in the step (2), the chlorinating agent is one selected from thionyl chloride, phosphorus oxychloride, oxalyl chloride and triphenylphosphine/carbon tetrachloride.
  6. 6. The method for synthesizing chloromethylstyrene according to claim 1, wherein in the step (2), the solvent used for the chlorination reaction is methylene chloride, chloroform or toluene.
  7. 7. The method for synthesizing chloromethyl styrene according to claim 1, wherein in the step (3), the base is one selected from sodium alkoxide, sodium hydride, potassium t-butoxide, and potassium carbonate.
  8. 8. The method for synthesizing chloromethylstyrene according to claim 1, wherein in the step (3), the Wittig reagent used in the Wittig reaction is methyltriphenylphosphine bromide or methyltriphenylphosphine chloride.
  9. 9. The method for synthesizing chloromethylstyrene according to claim 1, wherein in step (3), the solvent used in the Wittig reaction is tetrahydrofuran, diethyl ether or toluene.
  10. 10. The method for synthesizing chloromethylstyrene according to claim 9, wherein the Wittig reaction temperature is controlled from 0 ℃ to the reflux temperature of the solvent.

Description

Synthetic method of chloromethyl styrene Technical Field The invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing chloromethyl styrene. Background Chloromethyl styrene is an important high molecular monomer, a high molecular modifier and a fine chemical intermediate, for example, the molecular structure of the p-chloromethyl styrene contains vinyl and benzyl chloride groups at the same time, so that the p-chloromethyl styrene can be widely applied to the fields of ion exchange resins, high molecular supported catalysts, functional high molecular materials and the like through copolymerization and subsequent functional group conversion. The vinyl and benzyl chloride groups in the molecular structure of the m-chloromethyl styrene are in meta-position, so that the m-chloromethyl styrene has unique reactivity and space structure, and is widely applied to the fields of functional polymer materials, ion exchange resins, polymer supported catalysts, medical intermediates and the like. In the prior art, the synthetic route of the p-chloromethyl styrene mainly comprises a chlorination method which takes the p-methylstyrene as a raw material, namely, takes the p-methylstyrene as the raw material and takes chlorine or sulfonyl chloride as a chlorinating reagent, and the p-chloromethyl styrene is obtained through chlorination reaction. The method mainly has the following defects: (1) The selectivity is poor, the reaction is a free radical chlorination mechanism, the chlorination degree is difficult to control accurately, and when the methyl of the p-methylstyrene is chlorinated, the methyl is extremely easy to excessively chlorinate to generate a dichloro methyl and even a trichloromethyl byproduct, so that the product is complex, the separation and purification are extremely difficult, and the yield is obviously reduced. (2) Serious pollution and low safety, and usually uses highly toxic and highly corrosive reagents such as chlorine or sulfonyl chloride. The storage, transportation and use processes of the chlorine have extremely high safety risks, and the reaction tail gas possibly contains hydrogen chloride and unreacted chlorine, so that a complex absorption treatment device is needed, otherwise, equipment corrosion and environmental pollution can be caused. (3) The atomic economy is poor, in the reaction, only one chlorine atom enters the target product, and the other chlorine atom generates hydrogen chloride waste, so that the atomic utilization rate is low and the green chemistry principle is not met. The synthetic route of the m-chloromethyl styrene mainly comprises the steps of taking m-methylstyrene as a raw material, taking chlorine or sulfonyl chloride as a chlorinating reagent, and obtaining the m-chloromethyl styrene through chlorination reaction. The method mainly has the following defects: (1) The regioselectivity is poor, because of the positioning effect of meta substituent, the free radical chlorination reaction can occur not only on methyl, but also on other positions of benzene ring, various positional isomers are generated, the separation and purification are difficult, and the purity of the product is low; (2) The environment pollution is serious, namely, a great amount of chlorine-containing waste gas and waste water are generated in the reaction process by using a highly toxic chlorination reagent such as chlorine or sulfonyl chloride, the treatment cost is high, and the environmental burden is heavy; (3) The safety is poor, chlorine is extremely toxic gas, and the leakage risk exists in the storage and use processes, so that the safety of production equipment and operators is threatened. In summary, the prior art routes have significantly shorter plates in terms of chemical selectivity, safety, environmental friendliness and atomic economy, limiting their green, efficient and large-scale production of chloro/m-chloromethyl styrene. Therefore, there is an urgent need in the art to develop a new synthetic route that overcomes the above-mentioned drawbacks. Disclosure of Invention Aiming at the serious defects of the prior art in the aspects of selectivity, safety, environmental protection and atom economy, the invention provides a green method for synthesizing chloromethyl styrene, which takes terephthalaldehyde/isophthalaldehyde as a starting material and has the advantages of short steps, mild conditions, high selectivity, high yield, environmental protection and the like. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a method for synthesizing chloromethyl styrene comprises the following steps: (1) In the presence of a reducing agent, carrying out selective reduction reaction on terephthalaldehyde or isophthalaldehyde, reducing one aldehyde group into hydroxymethyl, and retaining the other aldehyde group to obtain p-hydroxymethyl benzaldehyde or 3- (hydroxymethyl) benzaldehyde