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CN-117623878-B - Synthesis method of 2-methoxypropene

CN117623878BCN 117623878 BCN117623878 BCN 117623878BCN-117623878-B

Abstract

The invention provides a synthetic method of 2-methoxypropene, which comprises the following steps: step A: in the presence of a first catalyst and an extractant, carrying out reverse contact reaction on ethylene glycol and acetone to generate acetone ethylene glycol, separating an extract containing the acetone ethylene glycol, and rectifying to obtain the acetone ethylene glycol; and (B) step (B): in the presence of a second catalyst, contacting the acetone-ethylene glycol with methanol, heating to 100-150 ℃, increasing the gauge pressure to 0.40-1.50 MPa, performing pressurized reaction rectification to generate 2-methoxypropene, and separating out the 2-methoxypropene as a target product; the method can reduce the reaction energy barrier, promote the synthesis of 2-methoxypropene under mild reaction conditions, is environment-friendly, low in energy consumption, less in byproduct impurities, low in raw and auxiliary material cost, simple in post-treatment and suitable for continuous industrial production; adopt pressurization reactive distillation, directly by acetone glycol condensation synthetic 2 methoxy propylene has reduced synthetic 2,2 dimethoxy propane and schizolysis preparation 2 methoxy propylene's process.

Inventors

  • ZHANG XIANNAN
  • ZHENG TAO
  • WANG ZHIPING
  • YU YONG

Assignees

  • 宁夏天新药业有限公司

Dates

Publication Date
20260508
Application Date
20231025

Claims (11)

  1. 1. A method for synthesizing 2-methoxypropene, which is characterized by comprising the following steps: in the presence of a first catalyst and an extractant, carrying out reverse contact reaction on ethylene glycol and acetone to generate acetone ethylene glycol, separating an extract containing the acetone ethylene glycol, and rectifying to obtain the acetone ethylene glycol; Step B, in the presence of a second catalyst, contacting the acetone-ethylene glycol with methanol, heating to 100-150 ℃, increasing the gauge pressure to 0.40-1.50MPa, performing pressurized reaction rectification to generate 2-methoxypropene, and separating out the 2-methoxypropene as a target product; In the step A, the reaction is carried out in a reaction extraction column, wherein ethylene glycol material containing a first catalyst enters from a feed inlet at the upper end of the reaction extraction column, acetone enters from a feed inlet at the middle part of the reaction extraction column, and extractant enters from a lower feed inlet of the reaction extraction column; In the step A, the extractant is selected from at least one of n-hexane, 2-methylpentane, 3-methylpentane, 2, 3-dimethylbutane and methylcyclopentane, the first catalyst is selected from at least one of ferric sulfate, ferric trichloride, aluminum sulfate, aluminum trichloride, zinc chloride and titanium tetrachloride, and in the step B, the second catalyst is selected from at least one of ferric sulfate, ferric trichloride, aluminum sulfate, aluminum trichloride, zinc chloride and titanium tetrachloride.
  2. 2. The method according to claim 1, wherein in the step B, in the presence of a second catalyst, the acetone-condensed glycol is contacted with methanol, the temperature is raised to 100-130 ℃, the gauge pressure is raised to 0.50-0.8MPa, pressurizing reaction rectification is carried out to generate 2-methoxypropene, and the 2-methoxypropene is separated as a target product.
  3. 3. The method according to claim 1, wherein, in step A, The materials entering the column are preheated to 40-55 ℃ and/or The concentration of the first catalyst in the ethylene glycol is 0.5 to 5wt%.
  4. 4. A process according to claim 3, wherein in step a the concentration of the first catalyst in the ethylene glycol is 0.5-2.5wt%.
  5. 5. The method according to claim 1, wherein, in step A, The volume flow rate ratio of the acetone, the glycol and the extractant is 1:1.2-8:1-10.
  6. 6. The process of claim 5, wherein in step A, the ratio of the volume flow rates of acetone, ethylene glycol and extractant is 1:3-4.5:4-6.
  7. 7. The method according to claim 1, wherein, in step A, The contact reaction conditions include a temperature of 40-55 ℃; And/or The purity of the acetone glycol is above 98% by weight percent.
  8. 8. The method according to claim 1, wherein, in step B, The step of separating 2-methoxy propylene includes the countercurrent extraction of the material containing 2-methoxy propylene obtained in the step B with detergent to obtain 2-methoxy propylene with purity over 99%.
  9. 9. The method of claim 8, wherein in step B, the detergent is selected from at least one of deionized water, dimethyl sulfoxide, ethylene glycol, propylene glycol, and glycerol.
  10. 10. The method according to claim 1, wherein, in step B, The feeding mole ratio of the acetone acetal to the methanol is 1:2.5-6, and/or The second catalyst is used in an amount of 0.01 to 3wt% based on the total weight of the liquid feedstock.
  11. 11. The process according to claim 10, wherein in step B the second catalyst is used in an amount of 0.2-1.6wt% based on the total weight of the liquid feedstock.

Description

Synthesis method of 2-methoxypropene Technical Field The invention relates to the technical field of organic chemical synthesis, in particular to a synthesis method of 2-methoxypropene. Background 2-Methoxy propylene is an important intermediate compound and is widely applied to the industrial fields of materials, medicines, dyes, feeds and the like. At present, the main synthetic route of 2 methoxy propylene is as follows: route 1, addition reaction of methanol and unsaturated hydrocarbon to produce 2-methoxypropene; Scheme 2 methoxypropenes are prepared by synthesizing 2,2 dimethoxypropane by an indirect or direct process followed by catalytic cracking of 2,2 dimethoxypropane by a gas phase or liquid phase process. Scheme 1 is simple in procedure, higher in reaction yield and good in selectivity, but the scheme has the following disadvantages: (1) The addition reaction catalyst has strong corrosion to equipment at high temperature; (2) The addition reaction is intense, difficult to control and poor in operation safety; (3) The source of the unsaturated hydrocarbon propyne or propadiene used is relatively difficult. The direct method of the route 2 for synthesizing the 2, 2-dimethoxy propane has the advantages that raw materials of methanol and acetone are cheap and easy to obtain, and industrial production is easy to realize. The disadvantages are lower conversion and the occurrence of azeotropes of methanol with acetone and 2, 2-dimethoxypropane. Scheme 2 indirect synthesis of 2,2 dimethoxypropane: (1) In the paper published in Shenyang university of industry, zhang Xiaojuan, 2004, ethylene glycol and acetone are used as raw materials, methylene dichloride is used as a water carrying agent to synthesize an intermediate 2, 2-dimethyl-1, 3-dioxolane, then the intermediate 2, 2-dimethoxypropane is exchanged with methanol to synthesize 2, 2-dimethoxypropane, and cyclohexane is added for rectification and separation of 2, 2-dimethoxypropane and methanol. In the route, the dichloromethane has poor water carrying capacity and is not thorough, and the effect of rectifying and separating 2,2 dimethoxy propane and methanol by adding cyclohexane is poor; (2) In the article of Shanxi chemical industry published in 2000 by the institute of Western-style modern chemistry Yang Shumin et al, propylene glycol and acetone are used as raw materials, petroleum ether at 30-60 ℃ is used as a water-carrying agent to synthesize an intermediate 2, 4-trimethyl-1, 3-dioxolane, then the intermediate 2, 2-dimethoxypropane is exchanged with methanol to synthesize 2, 2-dimethoxypropane, and the methanol is washed by alkaline water to purify the 2, 2-dimethoxypropane. The petroleum ether with water at the temperature of 30-60 ℃ in the route is still poor and incomplete, the methanol is removed by alkali water, and the post-treatment for recovering the methanol is complicated. In the gas phase cracking method in the route 2,2 dimethoxy propane is gasified and then is subjected to high-temperature catalytic cracking through a heated catalyst bed layer, so that 2 methoxy propylene is obtained. (1) In CN109776284A, gas phase cracking reaction is carried out in the presence of SAPO-34 molecular sieve catalyst, and the reaction product is separated by a partition type rectifying tower. (2) In CN110240540B, the catalyst is catalytically cracked under the synergistic effect of acid ceramic filler and promoter, and the separation and purification are carried out by adopting a method combining membrane separation technology and rectification. The gas phase cracking method has the problems of high energy consumption, high catalyst cost and service life. The liquid phase cracking method can catalytically crack 2,2 dimethoxy propane under mild conditions. (1) In the study of fine chemical intermediates, the reaction was promoted in the direction of 2 methoxypropene by adding benzoic acid and pyridine as catalysts, diglyme as solvent, and a certain amount of succinic anhydride to absorb methanol produced by cleavage, published by the institute of chemical and western-style recent institute Yang Shumin et al 2002. The rectification yield is 80.06 percent, and the purity of the product is more than 98 percent. The system adds significant cost due to the use of solvents and the introduction of succinic anhydride. (2) In 2009 from university of martial arts, li Xiaoxi et al, in Anhui chemical industry, benzoic acid and pyridine were used as catalysts, toluene was used as a solvent, and succinic anhydride was used to absorb methanol. The product yield can reach 81.1 percent, and the purity is more than 97 percent. In this system, the use of toluene instead of diglyme as a solvent reduces cost. However, the use of a solvent and the introduction of succinic anhydride make the reaction system too complex, which brings inconvenience to post-reaction treatment. (3) In U.S. Pat. No. 3,336, manfredKaufhold, pelargonic acid is used for catalytic pyrolysis of 2,