阅读说明：本技术 一种合成对羟基苯丙酸甲酯的工艺 (Process for synthesizing methyl p-hydroxyphenylpropionate ) 是由 郭骄阳 赵崇鑫 陈芬儿 程荡 黄则度 肖霄 于 2020-12-21 设计创作，主要内容包括：本发明公开了一种合成对羟基苯丙酸甲酯的工艺,以3-(3,5-二叔丁基-4-羟基)苯丙酸甲酯原料、酸性催化剂催化,在反应精馏釜中进行连续反应精馏,得到对羟基苯丙酸甲酯。本发明的工艺过程使原料得到充分利用,催化剂用量少,生产工艺简单,操作方便；同时生成的副产物异丁烯得到回收并可用作其他产品德文原料,使整个工艺过程中无三废生成,是环境友好型工艺；该合成工艺制得的对羟基苯丙酸甲酯产率较高,且质量优异,具有很好的工业生产价值。(The invention discloses a process for synthesizing methyl p-hydroxyphenylpropionate, which comprises the steps of catalyzing a 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate raw material and an acid catalyst, and carrying out continuous reaction rectification in a reaction rectification kettle to obtain the methyl p-hydroxyphenylpropionate. The technological process of the invention makes full use of the raw materials, the catalyst consumption is small, the production process is simple, and the operation is convenient; meanwhile, the generated byproduct isobutene is recycled and can be used as German raw materials of other products, so that three wastes are not generated in the whole process, and the process is environment-friendly; the methyl p-hydroxyphenylpropionate prepared by the synthesis process has high yield, excellent quality and good industrial production value.)

1. A process for synthesizing methyl p-hydroxyphenylpropionate is characterized by comprising the following steps:

(1) adding a catalyst into a reaction kettle of a reaction rectifying kettle;

(2) adding 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate into a premixing tank, and heating to 100-110 ℃ to melt the methyl phenylpropionate into liquid;

(3) continuously dropwise adding the liquid 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate in the step (2) into a reaction kettle of a reaction rectifying kettle through an advection pump with the flow rate of 4-12 ml/min for stirring reaction to generate a product methyl p-hydroxyphenylpropionate and a byproduct isobutene, and distilling materials in the reaction kettle through a rectifying tower of the reaction rectifying kettle;

(4) when the catalyst and the materials in the reaction kettle keep a certain weight ratio after the reaction is stable, controlling the reflux ratio of the top of the rectifying tower to continuously extract the materials in the reaction kettle through the top of the rectifying tower, extracting part of methyl p-hydroxyphenylpropionate and isobutene from the top of the rectifying tower, and refluxing the rest of methyl p-hydroxyphenylpropionate and 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate into the reaction kettle;

(5) after complete reaction, maintaining the reflux ratio of the top of the rectifying tower in the step (4), continuously extracting the materials in the reaction kettle from the top of the rectifying tower, extracting part of methyl p-hydroxyphenylpropionate and the top of the isobutene rectifying tower, and refluxing the rest of methyl p-hydroxyphenylpropionate into the reaction kettle until the methyl p-hydroxyphenylpropionate is completely extracted;

(6) and (5) separating methyl hydroxyphenylpropionate and isobutene extracted from the top of the rectifying tower in the step (4) and the step (5) by using a gas-liquid separation tank, recovering the gaseous isobutene into cold hydrazine by using a vacuum pump, and recovering the liquid methyl hydroxyphenylpropionate into a liquid tank to obtain a methyl hydroxyphenylpropionate product.

2. The process for synthesizing methyl p-hydroxyphenylpropionate according to claim 1, wherein the catalyst is one of phosphotungstic acid, silicotungstic acid, sulfonic acid resin amberlyst15 or sulfonic acid resin amberlyst 36.

3. The process for synthesizing methylparaben according to claim 2, wherein the catalyst is phosphotungstic acid.

4. The process for synthesizing methyl p-hydroxyphenylpropionate according to claim 1, wherein the pressure of the reaction rectifying still is between-2 and-1 kpa.

5. The process for synthesizing methyl p-hydroxyphenylpropionate according to claim 1, wherein the reaction temperature of the reaction kettle is 115-135 ℃.

6. The process for synthesizing methyl p-hydroxyphenylpropionate according to claim 1, wherein the weight ratio of the catalyst to the materials in the reaction kettle in the step (4) is 0.5-2: 100.

7. The process for synthesizing methyl p-hydroxyphenylpropionate according to claim 1, wherein the reflux ratio at the top of the rectifying tower is 1: 1-2: 1.

8. The process for synthesizing methylparaben according to claim 1, wherein the temperature at the top of the rectifying tower is 105-115 ℃.

9. The process for synthesizing methylparaben according to claim 1, wherein the number of plates in said rectifying column is 10.

10. The process for synthesizing methyl p-hydroxyphenylpropionate according to claim 1, wherein the reaction rectifying still comprises an integrally formed reaction still and a rectifying tower, and the rectifying tower is arranged at the top of the reaction still.

Technical Field

The invention relates to a process for synthesizing methyl p-hydroxyphenylpropionate, belonging to the technical field of fine chemical engineering.

Background

Methyl p-hydroxyphenylpropionate is an important organic fine chemical intermediate, can be used for synthesizing various compounds such as a stabilizer, a coloring agent and an optical material, and is also an important medical intermediate, and methyl p-hydroxyphenylpropionate is an important intermediate for preparing esmolol hydrochloride.

The currently reported synthetic routes of methyl p-hydroxyphenylpropionate, the synthetic routes in the documents of patents CN1200367A, CN108640834A and Shinde and the like require acylation, halogenation, hydrolysis and other steps, have low reaction yield and complex operation, generate a large amount of waste water and easily cause environmental pollution.

Therefore, in order to reduce the production cost, avoid the loss of raw materials, avoid the generation of three wastes and provide an environment-friendly production process, the invention provides a production process which takes 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate as a raw material to synthesize methyl p-hydroxyphenylpropionate and has positive significance.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a process for synthesizing methyl p-hydroxyphenylpropionate, which has the advantages of continuous reaction, simple process, easy operation and high yield and quality of good methyl p-hydroxyphenylpropionate products.

In order to achieve the purpose, the invention adopts the following technical scheme: a process for synthesizing methyl p-hydroxyphenylpropionate comprises the following steps:

(1) adding a catalyst into a reaction kettle of a reaction rectifying kettle;

(2) adding 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate into a premixing tank, and heating to 100-110 ℃ to melt the methyl phenylpropionate into liquid;

(3) continuously dropwise adding the liquid 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate in the step (2) into a reaction kettle of a reaction rectifying kettle through an advection pump with the flow rate of 4-12 ml/min for stirring reaction to generate a product methyl p-hydroxyphenylpropionate and a byproduct isobutene, and distilling materials in the reaction kettle through a rectifying tower of the reaction rectifying kettle;

(4) when the catalyst and the materials in the reaction kettle keep a certain weight ratio after the reaction is stable, controlling the reflux ratio of the top of the rectifying tower to continuously extract the materials in the reaction kettle through the top of the rectifying tower, extracting part of methyl p-hydroxyphenylpropionate and isobutene from the top of the rectifying tower, and refluxing the rest of methyl p-hydroxyphenylpropionate and 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate into the reaction kettle;

(5) after complete reaction, maintaining the reflux ratio of the top of the rectifying tower in the step (4), continuously extracting the materials in the reaction kettle from the top of the rectifying tower, extracting part of methyl p-hydroxyphenylpropionate and the top of the isobutene rectifying tower, and refluxing the rest of methyl p-hydroxyphenylpropionate into the reaction kettle until the methyl p-hydroxyphenylpropionate is completely extracted;

(6) and (5) separating methyl hydroxyphenylpropionate and isobutene extracted from the top of the rectifying tower in the step (4) and the step (5) by using a gas-liquid separation tank, recovering the gaseous isobutene into cold hydrazine by using a vacuum pump, and recovering the liquid methyl hydroxyphenylpropionate into a liquid tank to obtain a methyl hydroxyphenylpropionate product.

Wherein the catalyst is one of phosphotungstic acid, silicotungstic acid, sulfonic acid resin amberlyst15 or sulfonic acid resin amberlyst 36.

Furthermore, the catalyst is phosphotungstic acid.

Wherein the pressure of the reaction rectifying kettle is-2 to-1 kpa.

Wherein the reaction temperature is 115-135 ℃.

Wherein, the weight ratio of the catalyst to the materials in the reaction kettle in the step (4) is 0.5-2: 100.

Wherein the reflux ratio of the top of the rectifying tower is 1: 1-2: 1.

Wherein the temperature of the top of the rectifying tower is 105-115 ℃.

Wherein, the number of the tower plates of the rectifying tower is 10.

The reaction rectifying kettle comprises an integrally formed reaction kettle and a rectifying tower, and the rectifying tower is arranged at the top of the reaction kettle.

The invention has the beneficial effects that: according to the process method for synthesizing methyl p-hydroxyphenylpropionate, the methyl 3- (3, 5-di-tert-butyl-4-hydroxy) phenylpropionate raw material and an acidic catalyst are used for catalysis, and continuous reaction rectification is carried out in a reaction rectification kettle to obtain the methyl p-hydroxyphenylpropionate, so that the raw material is fully utilized, the catalyst dosage is small, the production process is simple, and the operation is convenient; the byproduct isobutene generated in the synthesis process is recycled and can be used as other product raw materials, so that no three wastes are generated in the whole process, and the synthesis process is an environment-friendly process; the methyl p-hydroxyphenylpropionate prepared by the synthesis process has high yield, excellent quality and good industrial production value.

Drawings

FIG. 1 is a chemical reaction scheme of the present invention;

FIG. 2 is a process flow diagram of the present invention.

Detailed Description

In order to more clearly and completely illustrate the present invention, the following examples are given by way of illustration of the present invention, and are not intended to limit the present invention.

The reactive distillation kettle used in the embodiment 1-11 comprises a reaction kettle and a distillation column which are integrally formed, wherein the distillation column is arranged at the top of the reaction kettle, the number of the column plates of the distillation column is 10, and the pressure of the reaction distillation kettle is-2 to-1 kpa.

Example 1

Preparation of methyl p-hydroxyphenylpropionate: continuously dropwise adding 500g of liquid 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate with the temperature of 100 ℃ into a reaction kettle containing 1.0g of phosphotungstic acid catalyst by an advection pump with the flow rate of 4ml/min, stirring and reacting at the temperature of 115 ℃ (chemical reaction formula is shown in figure 1) to generate methyl p-hydroxyphenylpropionate and a byproduct isobutene, distilling the materials in the reaction kettle by a rectifying tower, wherein the temperature at the top of the rectifying tower is 105 ℃, the pressure of the reaction kettle and the rectifying tower is-1 kpa, reacting stably, then obtaining about 100g of the materials in the reaction kettle, controlling the reflux ratio at the top of the rectifying tower to be 1:1, continuously extracting the materials in the reaction kettle from the top of the rectifying tower, extracting part of the methyl p-hydroxyphenylpropionate and the isobutene from the top of the rectifying tower, and the rest of the methyl p-hydroxyphenylpropionate and the 3- (3), refluxing the 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate to the reaction kettle; after complete reaction, maintaining the reflux ratio of the top of the rectifying tower, continuously extracting the materials in the reaction kettle through the top of the rectifying tower, extracting part of methyl p-hydroxyphenylpropionate and isobutene from the top of the rectifying tower, refluxing the rest of methyl p-hydroxyphenylpropionate into the reaction kettle until the methyl p-hydroxyphenylpropionate is completely extracted, separating the extracted methyl p-phenylpropionate and isobutene through a gas-liquid separation tank, recovering gaseous isobutene into cold hydrazine through a vacuum pump, and recovering liquid methyl p-hydroxyphenylpropionate into a liquid tank to obtain a methyl p-hydroxyphenylpropionate product.

The obtained methyl p-hydroxyphenylpropionate was weighed and analyzed by gas chromatography to obtain 280g of methyl p-hydroxyphenylpropionate, the yield was 90.9%, and the purity was 99.5%.

Example 2

Preparation of methyl p-hydroxyphenylpropionate: continuously dropwise adding 500g of liquid 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate with the temperature of 100 ℃ into a reaction kettle containing 1.0g of phosphotungstic acid catalyst by an advection pump with the flow rate of 5ml/min, stirring and reacting at the temperature of 125 ℃ to generate a product methyl p-hydroxyphenylpropionate and a byproduct isobutene, distilling materials in the reaction kettle by a rectifying tower, controlling the temperature at the top of the rectifying tower to be 111 ℃, controlling the pressure of the reaction kettle and the rectifying tower to be-1 kpa, ensuring the weight of the materials in the reaction kettle to be about 100g after the reaction is stabilized, controlling the reflux ratio at the top of the rectifying tower to be 1.5:1, and continuously extracting the materials in the reaction kettle through the top of the rectifying tower; after complete reaction, maintaining the reflux ratio of the top of the rectifying tower, continuously extracting the materials in the reaction kettle from the top of the rectifying tower, separating the extracted methyl hydroxyphenylpropionate and isobutene in a gas-liquid separation tank, recovering the gaseous isobutene into cold hydrazine by a vacuum pump, and recovering the liquid methyl hydroxyphenylpropionate into a liquid tank to obtain the methyl hydroxyphenylpropionate product.

The obtained methyl p-hydroxyphenylpropionate was weighed and analyzed by gas chromatography to obtain 282g of methyl p-hydroxyphenylpropionate, the yield was 91.6%, and the purity was 99.3%.

Example 3

Preparation of methyl p-hydroxyphenylpropionate: continuously dropwise adding 500g of liquid 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate with the temperature of 100 ℃ into a reaction kettle containing 1.0g of phosphotungstic acid catalyst by an advection pump with the flow rate of 6ml/min, stirring and reacting at the temperature of 135 ℃ to generate a product methyl p-hydroxyphenylpropionate and a byproduct isobutene, distilling materials in the reaction kettle by a rectifying tower, controlling the temperature at the top of the rectifying tower to be 115 ℃, controlling the pressure of the reaction kettle and the rectifying tower to be-1 kpa, ensuring the weight of the materials in the reaction kettle to be about 100g after the reaction is stabilized, controlling the reflux ratio at the top of the rectifying tower to be 2:1, and continuously extracting the materials in the reaction kettle from the top of the rectifying tower; after complete reaction, maintaining the reflux ratio of the top of the rectifying tower, continuously extracting the materials in the reaction kettle from the top of the rectifying tower, separating the extracted methyl hydroxyphenylpropionate and isobutene in a gas-liquid separation tank, recovering the gaseous isobutene into cold hydrazine by a vacuum pump, and recovering the liquid methyl hydroxyphenylpropionate into a liquid tank to obtain the methyl hydroxyphenylpropionate product.

The methyl p-hydroxyphenylpropionate obtained was weighed and analyzed by gas chromatography to obtain 283g of methyl p-hydroxyphenylpropionate, the yield was 91.9%, and the purity was 98.9%.

Example 4

Preparation of methyl p-hydroxyphenylpropionate: continuously dropwise adding 500g of liquid 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate with the temperature of 110 ℃ into a reaction kettle containing 1.0g of phosphotungstic acid catalyst by an advection pump with the flow rate of 8ml/min, stirring and reacting at the temperature of 125 ℃ to generate a product methyl p-hydroxyphenylpropionate and a byproduct isobutene, distilling materials in the reaction kettle by a rectifying tower, controlling the temperature at the top of the rectifying tower to be 111 ℃, controlling the pressure of the reaction kettle and the rectifying tower to be-1 kpa, ensuring the weight of the materials in the reaction kettle to be about 100g after the reaction is stabilized, controlling the reflux ratio at the top of the rectifying tower to be 1.5:1, and continuously extracting the materials in the reaction kettle through the top of the rectifying tower; after complete reaction, maintaining the reflux ratio of the top of the rectifying tower, continuously extracting the materials in the reaction kettle from the top of the rectifying tower, separating the extracted methyl hydroxyphenylpropionate and isobutene in a gas-liquid separation tank, recovering the gaseous isobutene into cold hydrazine by a vacuum pump, and recovering the liquid methyl hydroxyphenylpropionate into a liquid tank to obtain the methyl hydroxyphenylpropionate product.

The obtained methyl p-hydroxyphenylpropionate was weighed and analyzed by gas chromatography to obtain 285g of methyl p-hydroxyphenylpropionate, the yield was 92.5%, and the purity was 99.3%.

Example 5

Preparation of methyl p-hydroxyphenylpropionate: continuously dropwise adding 500g of liquid 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate with the temperature of 100 ℃ into a reaction kettle containing 0.5g of phosphotungstic acid catalyst by an advection pump with the flow rate of 10ml/min, stirring and reacting at the temperature of 125 ℃ to generate a product methyl p-hydroxyphenylpropionate and a byproduct isobutene, distilling materials in the reaction kettle by a rectifying tower, controlling the temperature at the top of the rectifying tower to be 108 ℃, controlling the pressure of the reaction kettle and the rectifying tower to be-1 kpa, ensuring the weight of the materials in the reaction kettle to be about 100g after the reaction is stabilized, controlling the reflux ratio at the top of the rectifying tower to be 1.5:1, and continuously extracting the materials in the reaction kettle through the top of the rectifying tower; after complete reaction, maintaining the reflux ratio of the top of the rectifying tower, continuously extracting the materials in the reaction kettle from the top of the rectifying tower, separating the extracted methyl hydroxyphenylpropionate and isobutene in a gas-liquid separation tank, recovering the gaseous isobutene into cold hydrazine by a vacuum pump, and recovering the liquid methyl hydroxyphenylpropionate into a liquid tank to obtain the methyl hydroxyphenylpropionate product.

The obtained methyl p-hydroxyphenylpropionate was weighed and analyzed by gas chromatography to obtain 274g of methyl p-hydroxyphenylpropionate, the yield was 89.0%, and the purity was 99.4%.

Example 6

Preparation of methyl p-hydroxyphenylpropionate: continuously dropwise adding 500g of liquid 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate with the temperature of 100 ℃ into a reaction kettle containing 2.0g of phosphotungstic acid catalyst by an advection pump with the flow rate of 6ml/min, stirring and reacting at the temperature of 125 ℃ to generate a product methyl p-hydroxyphenylpropionate and a byproduct isobutene, distilling materials in the reaction kettle by a rectifying tower, controlling the temperature at the top of the rectifying tower to be 115 ℃, controlling the pressure of the reaction kettle and the rectifying tower to be-2 kpa, ensuring the weight of the materials in the reaction kettle to be about 100g after the reaction is stabilized, controlling the reflux ratio at the top of the rectifying tower to be 1.5:1, and continuously extracting the materials in the reaction kettle through the top of the rectifying tower; after complete reaction, maintaining the reflux ratio of the top of the rectifying tower, continuously extracting the materials in the reaction kettle from the top of the rectifying tower, separating the extracted methyl hydroxyphenylpropionate and isobutene in a gas-liquid separation tank, recovering the gaseous isobutene into cold hydrazine by a vacuum pump, and recovering the liquid methyl hydroxyphenylpropionate into a liquid tank to obtain the methyl hydroxyphenylpropionate product.

The obtained methyl p-hydroxyphenylpropionate was weighed and analyzed and detected by gas chromatography to obtain 284g of methyl p-hydroxyphenylpropionate, the yield was 92.2%, and the purity was 99.4%.

Example 7

Preparation of methyl p-hydroxyphenylpropionate: continuously dropwise adding 1000g of liquid 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate with the temperature of 100 ℃ into a reaction kettle containing 2.0g of phosphotungstic acid catalyst by using an advection pump with the flow rate of 12ml/min, stirring and reacting at the temperature of 125 ℃ to generate a product methyl p-hydroxyphenylpropionate and a byproduct isobutene, distilling materials in the reaction kettle by using a rectifying tower, controlling the temperature at the top of the rectifying tower to be 112 ℃, controlling the pressure of the reaction kettle and the rectifying tower to be-1.2 kpa, ensuring the weight of the materials in the reaction kettle to be about 200g after the reaction is stable, controlling the reflux ratio at the top of the rectifying tower to be 1.5:1, and continuously extracting the materials in the reaction kettle through the top of the rectifying tower; after complete reaction, maintaining the reflux ratio of the top of the rectifying tower, continuously extracting the materials in the reaction kettle from the top of the rectifying tower, separating the extracted methyl hydroxyphenylpropionate and isobutene in a gas-liquid separation tank, recovering the gaseous isobutene into cold hydrazine by a vacuum pump, and recovering the liquid methyl hydroxyphenylpropionate into a liquid tank to obtain the methyl hydroxyphenylpropionate product.

The obtained methyl p-hydroxyphenylpropionate was weighed and analyzed by gas chromatography to obtain 565g of methyl p-hydroxyphenylpropionate, the yield was 91.7%, and the purity was 99.3%.

Example 8

Preparation of methyl p-hydroxyphenylpropionate: continuously dropwise adding 1000g of liquid 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate with the temperature of 100 ℃ into a reaction kettle containing 2.0g of phosphotungstic acid catalyst by using an advection pump with the flow rate of 8ml/min, stirring and reacting at the temperature of 135 ℃ to generate a product methyl p-hydroxyphenylpropionate and a byproduct isobutene, distilling materials in the reaction kettle by using a rectifying tower, controlling the temperature at the top of the rectifying tower to be 113 ℃, controlling the pressure of the reaction kettle and the rectifying tower to be-1.2 kpa, ensuring the weight of the materials in the reaction kettle to be about 200g after the reaction is stabilized, controlling the reflux ratio at the top of the rectifying tower to be 2:1, and continuously extracting the materials in the reaction kettle from the top of the rectifying tower; after complete reaction, maintaining the reflux ratio of the top of the rectifying tower, continuously extracting the materials in the reaction kettle from the top of the rectifying tower, separating the extracted methyl hydroxyphenylpropionate and isobutene in a gas-liquid separation tank, recovering the gaseous isobutene into cold hydrazine by a vacuum pump, and recovering the liquid methyl hydroxyphenylpropionate into a liquid tank to obtain the methyl hydroxyphenylpropionate product.

The obtained methyl p-hydroxyphenylpropionate was weighed and analyzed by gas chromatography to obtain 570g of methyl p-hydroxyphenylpropionate, the yield was 92.5%, and the purity was 99.0%.

Example 9

Preparation of methyl p-hydroxyphenylpropionate: continuously dropwise adding 500g of liquid 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate with the temperature of 100 ℃ into a reaction kettle containing 2.0g of silicotungstic acid catalyst by an advection pump with the flow rate of 6ml/min, stirring and reacting at the temperature of 135 ℃ to generate a product of methyl p-hydroxyphenylpropionate and a byproduct of isobutene, distilling materials in the reaction kettle by a rectifying tower, controlling the temperature at the top of the rectifying tower to be 109 ℃, controlling the pressure of the reaction kettle and the rectifying tower to be-1 kpa, ensuring the weight of the materials in the reaction kettle to be about 100g after the reaction is stable, controlling the reflux ratio at the top of the rectifying tower to be 2:1, and continuously extracting the materials in the reaction kettle from the top of the rectifying tower; after complete reaction, maintaining the reflux ratio of the top of the rectifying tower, continuously extracting the materials in the reaction kettle from the top of the rectifying tower, separating the extracted methyl hydroxyphenylpropionate and isobutene in a gas-liquid separation tank, recovering the gaseous isobutene into cold hydrazine by a vacuum pump, and recovering the liquid methyl hydroxyphenylpropionate into a liquid tank to obtain the methyl hydroxyphenylpropionate product.

The methyl p-hydroxyphenylpropionate obtained was weighed and analyzed by gas chromatography to obtain 270g of methyl p-hydroxyphenylpropionate, the yield was 88.7%, and the purity was 99.4%.

Example 10

Preparation of methyl p-hydroxyphenylpropionate: continuously dropwise adding 500g of liquid 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate with the temperature of 100 ℃ into a reaction kettle containing 2.0g of sulfonic acid resin amberlyst15 catalyst by an advection pump with the flow rate of 6ml/min, and carrying out stirring reaction at the temperature of 125 ℃ to generate a product of methyl p-hydroxyphenylpropionate and a byproduct of isobutene, distilling materials in the reaction kettle by a rectifying tower, wherein the temperature at the top of the rectifying tower is 110 ℃, the pressure of the reaction kettle and the rectifying tower is-1 kpa, the weight of the materials in the reaction kettle is about 100g after the reaction is stabilized, controlling the reflux ratio at the top of the rectifying tower to be 1.5:1, and continuously extracting the materials in the reaction kettle from the top of the rectifying tower; after complete reaction, maintaining the reflux ratio of the top of the rectifying tower, continuously extracting the materials in the reaction kettle from the top of the rectifying tower, separating the extracted methyl hydroxyphenylpropionate and isobutene in a gas-liquid separation tank, recovering the gaseous isobutene into cold hydrazine by a vacuum pump, and recovering the liquid methyl hydroxyphenylpropionate into a liquid tank to obtain the methyl hydroxyphenylpropionate product.

The obtained methyl p-hydroxyphenylpropionate was weighed and analyzed and detected by gas chromatography to obtain 264g of methyl p-hydroxyphenylpropionate, the yield was 85.7%, and the purity was 99.1%.

Example 11

Preparation of methyl p-hydroxyphenylpropionate: continuously dropwise adding 500g of liquid 3- (3, 5-di-tert-butyl-4-hydroxy) methyl phenylpropionate with the temperature of 100 ℃ into a reaction kettle containing 2.0g of sulfonic acid resin amberlyst36 catalyst by an advection pump with the flow rate of 6ml/min, and carrying out stirring reaction at the temperature of 135 ℃ to generate a product of methyl p-hydroxyphenylpropionate and a byproduct of isobutene, distilling the materials in the reaction kettle by a rectifying tower, wherein the temperature at the top of the rectifying tower is 112 ℃, the pressure of the reaction kettle and the rectifying tower is-1 kpa, the weight of the materials in the reaction kettle is about 100g after the reaction is stabilized, controlling the reflux ratio at the top of the rectifying tower to be 2:1, and continuously extracting the materials in the reaction kettle from the top of the rectifying tower; after complete reaction, maintaining the reflux ratio of the top of the rectifying tower, continuously extracting the materials in the reaction kettle from the top of the rectifying tower, separating the extracted methyl hydroxyphenylpropionate and isobutene in a gas-liquid separation tank, recovering the gaseous isobutene into cold hydrazine by a vacuum pump, and recovering the liquid methyl hydroxyphenylpropionate into a liquid tank to obtain the methyl hydroxyphenylpropionate product.

The methyl p-hydroxyphenylpropionate obtained was weighed and analyzed by gas chromatography to obtain 269g of methyl p-hydroxyphenylpropionate, the yield was 87.3%, and the purity was 99.2%.

Finally, it should be noted that the above embodiments are only used for illustrating and not limiting the technical solutions of the present invention, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made to the present invention without departing from the spirit and scope of the present invention, and all modifications or partial substitutions should be covered by the scope of the claims of the present invention.