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CN-122010660-A - Method for preparing 1, 2-bis (4-vinyl phenyl) ethane

CN122010660ACN 122010660 ACN122010660 ACN 122010660ACN-122010660-A

Abstract

The invention relates to a method for preparing 1, 2-bis (4-vinyl phenyl) ethane, which relates to the technical field of organic chemistry, wherein the preparation method comprises the following steps of (1) mixing a compound 1, p-toluenesulfonyl hydrazine and an organic solvent 1, then reacting to obtain a compound 2, and (2) reacting the compound 2 in the organic solvent 2 under the action of alkali and a polymerization inhibitor to generate 1, 2-bis (4-vinyl phenyl) ethane. The method has the advantages of mild reaction conditions, simple operation, high product purity and high yield, and is suitable for industrial production.

Inventors

  • ZHANG HUIMIAO
  • YAN LIHAO
  • PAN ZHAOXI

Assignees

  • 济南鼎皓医药科技有限公司

Dates

Publication Date
20260512
Application Date
20260415

Claims (10)

  1. 1. A process for the preparation of 1, 2-bis (4-vinylphenyl) ethane, characterized by the following reaction scheme: the preparation method comprises the following steps: (1) Adding the compound 1 and the p-toluenesulfonyl hydrazine into an organic solvent for mixing to obtain a compound 2; (2) The compound 2 reacts in an organic solvent under the action of alkali and a polymerization inhibitor to generate 1, 2-bis (4-vinyl phenyl) ethane.
  2. 2. A process for the preparation of 1, 2-bis (4-vinylphenyl) ethane according to claim 1, wherein the equivalent weight of p-toluenesulfonyl hydrazide is 2-3eq.
  3. 3. A process for the preparation of 1, 2-bis (4-vinylphenyl) ethane according to claim 2, characterized in that the equivalent weight of p-toluenesulfonyl hydrazide is 2.4-2.6eq.
  4. 4. The method for preparing 1, 2-bis (4-vinylphenyl) ethane according to claim 1, wherein the organic solvent in the step (1) is any one of 1, 2-dichloroethane, ethanol, and methanol.
  5. 5. A process for the preparation of 1, 2-bis (4-vinylphenyl) ethane according to claim 1, wherein the reaction temperature in step (1) is 60-90 ℃ and the reaction time is 1-4 h.
  6. 6. The method for preparing 1, 2-bis (4-vinyl phenyl) ethane according to claim 1, wherein the equivalent weight of the base is 5-7eq, and the base is at least one of potassium carbonate, sodium tert-butoxide, sodium methoxide and sodium hydroxide.
  7. 7. A process for the preparation of 1, 2-bis (4-vinylphenyl) ethane according to claim 1, wherein the mass of the polymerization inhibitor is 1.5-2% of the mass of the compound 2, and the polymerization inhibitor is p-tert-butylcatechol.
  8. 8. The method for producing 1, 2-bis (4-vinylphenyl) ethane according to claim 1, wherein the organic solvent in the step (2) is any one of N, N-dimethylformamide, dimethylacetamide and dimethylsulfoxide.
  9. 9. A process for the preparation of 1, 2-bis (4-vinylphenyl) ethane according to claim 1, wherein the reaction temperature in step (2) is 80-100 ℃ and the reaction time is 4-6 h.
  10. 10. 1, 2-Bis (4-vinylphenyl) ethane, characterized in that it is prepared by the process according to any one of claims 1 to 9, the purity of said 1, 2-bis (4-vinylphenyl) ethane being greater than or equal to 92% and the yield being greater than or equal to 71%.

Description

Method for preparing 1, 2-bis (4-vinyl phenyl) ethane Technical Field The invention relates to the technical field of organic chemistry, in particular to a method for preparing 1, 2-bis (4-vinyl phenyl) ethane. Background 1, 2-Bis (4-vinyl phenyl) ethane is taken as an important difunctional styrene monomer, is widely applied to the fields of 3D printing crosslinking resin, electronic packaging materials, high-frequency substrates, photoresist resin, printed Circuit Board (PCB) laminates and the like, and has the characteristics of good mechanical property, heat resistance, low dielectric constant, low dielectric loss and the like. In the prior art, the synthesis method comprises the following steps: (1) The Wittig reaction process is one Chinese patent No. CN120794805A and is one process of synthesizing 1, 2-bis (4-vinyl phenyl) ethane with 1, 2-bis (p-formaldehyde phenyl) ethane as material and methyl triphenyl phosphine halide to react under the action of alkali to prepare 1, 2-bis (4-vinyl phenyl) ethane. However, the method has high raw material cost, complex post-reaction treatment and possible generation of isomer impurities. (2) The metal coupling process is that Chinese patent No. CN119263950A discloses a synthesis process of 1, 2-bis (4-vinyl phenyl) ethane, which uses p-halobenzyl halide as raw material, and adopts self-coupling reaction catalyzed by metal magnesium or zinc to obtain 1, 2-bis (4-halogen phenyl) ethane, and then makes it undergo the process of coupling with vinyl Grignard reagent or vinyl chloride to prepare 1, 2-bis (4-vinyl phenyl) ethane. However, the method has high raw material cost, uses the highly toxic substance vinyl chloride and the explosive metal, has potential safety hazard, and has strict reaction conditions and complex operation. (3) The acid catalytic dehydration method, chinese patent publication No. CN113372187A discloses an industrialized synthesis method of BVPE, which comprises the steps of reducing a compound 1 and reacting with p-toluenesulfonic acid serving as a catalyst. Chinese patent publication No. CN115385767a discloses a process for preparing a divinylaromatic compound, in which compound 1 is reduced and then dehydrated using pyridinium p-toluenesulfonate as a catalyst. The preparation method is simple in preparation process, but the concentration and the reaction time of the acid catalyst are strictly controlled, and the product is easy to polymerize under the acidic condition, so that the high-purity monomer is difficult to obtain, the yield is low, and the method is not suitable for industrialization. Thus, there is a need to develop a new process for the preparation of 1, 2-bis (4-vinylphenyl) ethane. Disclosure of Invention In order to solve the technical problems, the invention provides a method for preparing 1, 2-bis (4-vinyl phenyl) ethane. The method has the advantages of mild reaction conditions, simple operation, high product purity and high yield, and is suitable for industrial production. In a first aspect, the present invention provides a process for preparing 1, 2-bis (4-vinylphenyl) ethane, having the following reaction formula: the preparation method comprises the following steps: (1) Mixing the compound 1, p-toluenesulfonyl hydrazine and the organic solvent 1, and then reacting to obtain a compound 2; (2) The compound 2 reacts in an organic solvent 2 under the action of alkali and a polymerization inhibitor to generate 1, 2-bis (4-vinyl phenyl) ethane. In the technical scheme, the step (1) is a hydrazinization reaction, and the compound 1 (1, 2-bis (4-acetylphenyl) ethane) and p-toluenesulfonyl hydrazine react under proper conditions to generate a stable dihydrazone intermediate, namely the compound 2. The step realizes the conversion from carbonyl to hydrazone, provides a key precursor for the subsequent elimination reaction, and has mild reaction conditions, high conversion rate and easy separation and purification of intermediates. Step (2) is a base-driven elimination reaction, wherein the base acts on the beta-methylene of the hydrazone group in the compound 2 to deprotonate the hydrazone group, so that the elimination reaction is initiated. After two times of elimination, two vinyl groups are generated, and finally the 1, 2-bis (4-vinyl phenyl) ethane is obtained. Alternatively, the equivalent weight of the p-toluenesulfonyl hydrazide is 2 to 3eq, and preferably, the equivalent weight of the p-toluenesulfonyl hydrazide is 2.4 to 2.6eq. In the technical scheme, 2-3eq equivalent of p-toluenesulfonyl hydrazide is used to ensure that two carbonyl groups completely react, so that raw material residues are avoided. Preferably 2.4 to 2.6eq equivalent reduces the work-up burden of excess reagent while ensuring high conversion. Optionally, the organic solvent 1 is any one of 1, 2-dichloroethane, ethanol and methanol, and preferably, the organic solvent 1 is 1, 2-dichloroethane. In the technical scheme, the selected organic solvent 1 can