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A kind of preparation method of 4-methoxystyrene

A technology of methoxystyrene and methoxyacetophenone, applied in the field of preparation of 4-methoxystyrene, can solve the problems of inability to obtain high-purity products, lack of high-purity products, unavoidable polymerization, etc. Solve the effects of harsh raw material requirements, high product purity and simple process

Active Publication Date: 2016-07-06
华诺森(武汉)生物医药技术有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this method, when the pyrolysis elimination reaction occurs, the conversion rate is better, but it still cannot avoid the polymerization of the product in the pyrolysis tube, and the high-purity product cannot be obtained;
[0009] In summary, in the existing synthetic method of 4-methoxystyrene, there is a lack of a synthetic method with simple process, cheap and easy raw materials, and no special equipment requirements. routes, lack of methods to obtain high-purity products

Method used

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Examples

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preparation example Construction

[0030] The invention provides a kind of preparation method of 4-methoxystyrene, comprises the following steps:

[0031] (1) Dissolve 4-methoxyacetophenone in ethanol with a volume fraction of 95%, stir, heat up, add reducing agent in batches for reduction reaction, the reaction temperature is 20-80°C, and the reaction time is 1- 3h. After the reaction is finished, add water equal to the volume of ethanol, stir thoroughly, and remove excess reducing agent and the complex obtained by the reducing agent reaction. Then it was extracted with ethyl acetate, the layers were separated, the organic phase was dried and concentrated. Distillation, the distillation temperature is 90-110°C, the vacuum degree is 0-1mmHg, and the intermediate 1-(4-methoxyphenyl)ethanol is obtained;

[0032] (2) Heat the oil bath to the set reaction temperature of 150-220°C in advance, then add potassium bisulfate and a small amount of 1-(4-methoxyphenyl)ethanol into the reaction flask, most of the 1- Ad...

Embodiment 1

[0041] a Reduction reaction: Add 2 kg of 4-methoxyacetophenone and 4 L of ethanol with a volume fraction of 95% in a three-neck flask with a capacity of 10 L. After heating to 30°C in a water bath, a total of 240 g of potassium borohydride was added in batches. After the addition, keep the temperature of the water bath constant, continue the reaction for 3 hours, and monitor by gas chromatography. After confirming that there is no 4-methoxyacetophenone remaining, add 4L of tap water to terminate the reaction, stir for 45 minutes, and then start the extraction. Add 4.5L ethyl acetate for the first time to extract, and add 0.5L ethyl acetate to the remaining water phase to extract twice. Combine the organic phases, add anhydrous sodium sulfate whose mass fraction is 5% of the mass of the organic phase, and dry for 3 h. After filtration, the filtrate was rotary evaporated to remove the solvent to obtain 1.993 kg of crude intermediate. Further distillation and purification (di...

Embodiment 2

[0046] a Reduction reaction: Add 2 kg of 4-methoxyacetophenone and 4 L of ethanol with a volume fraction of 95% in a three-neck flask with a capacity of 10 L. After heating to 30°C in a water bath, 185 g of potassium borohydride was added in batches. After the addition, keep the temperature of the water bath constant, continue the reaction for 5 h, monitor by gas chromatography, after confirming that there is no 4-methoxyacetophenone remaining, add 4 L of tap water to terminate the reaction, stir for 45 min, and start the extraction. Add 4.5L ethyl acetate for the first time to extract, and add 0.5L ethyl acetate to the remaining water phase to extract twice. Combine the organic phases, add anhydrous sodium sulfate whose mass fraction is 5% of the mass of the organic phase, and dry for 3 h. After filtration, the filtrate was rotary evaporated to remove the solvent to obtain 1.996 kg of crude intermediate. Further distillation and purification (distillation temperature 100°...

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Abstract

The invention relates to a preparation method of 4-methoxystyrene, comprising the following steps: (1) dissolving 4-methoxyacetophenone in an alcohol solvent, adding a reducing agent for reduction reaction, and obtaining intermediate 1- (4-methoxyphenyl)ethanol; (2) The intermediate obtained in step (1) is dehydrated under the catalysis of a dehydrating agent, and distilled at the same time to obtain the crude product 4-methoxystyrene. The preparation method of 4-methoxystyrene provided by the present invention has easy-to-obtain raw materials, simple process, high reaction yield, high product purity, and no need to add a polymerization inhibitor, which solves the problem of harsh raw material requirements and post-treatment in the existing synthetic methods. Problems such as difficulty, easy polymerization of reaction, non-continuous production and harsh production equipment requirements can be effectively applied to production practice.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a preparation method of 4-methoxystyrene. Background technique [0002] Styrenic compounds are important monomers for the synthesis of polystyrene resins. The substituents on the benzene ring can endow the polystyrene resins with various properties. They are widely used in materials, pharmaceutical intermediates, adhesives, Coatings, sunscreen and other fields. Both water and oil repelling properties of substituted polystyrene compounds are excellent. The polymer of p-methoxystyrene is an excellent anti-corrosion material, which is widely used in the information industry. There are many literature reports on its synthesis method. The specific methods are as follows: [0003] 1. Patents DE2317525 and EP128984 provide a method for obtaining styrene by catalytic dehydrogenation reaction using ethylbenzene as a raw material. The disadvantages of this method are low yield, poor pur...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C43/215C07C41/18
CPCC07C41/18C07C41/26C07C43/23C07C43/215
Inventor 张爱军
Owner 华诺森(武汉)生物医药技术有限公司