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CN-121990912-A - Preparation process of 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor

CN121990912ACN 121990912 ACN121990912 ACN 121990912ACN-121990912-A

Abstract

The invention relates to the technical field of chemical synthesis and provides a preparation process of a 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor, which comprises the following steps of S1, adding 4-chloro-2-methylphenol and potassium hydroxide into absolute ethyl alcohol, stirring to obtain a product 1, S2, adding the product 1 and the methyl 2-bromopropionate into absolute DMF, heating and refluxing, pouring the product into water at 0-4 ℃, suction filtering, washing, adding the product into absolute ethyl alcohol, stirring, adding sodium hydroxide, heating and refluxing at 80-85 ℃ for 2-4 hours, recovering room temperature, regulating pH=2-3, suction filtering, washing to obtain a product 2, S3, adding the product 2, PEG-200, a catalyst and a polymerization inhibitor into toluene, heating and stirring, filtering, recovering the catalyst, taking an organic phase, adding sodium bicarbonate aqueous solution, removing water and removing toluene to obtain the 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester. The 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester obtained by the preparation process provided by the invention has the characteristics of high yield, and the catalyst is easy to separate and has low corrosiveness.

Inventors

  • WANG LIQIANG
  • MOU TAO
  • BAI YU
  • XIN WEI

Assignees

  • 营口理工学院

Dates

Publication Date
20260508
Application Date
20260129

Claims (10)

  1. 1. The preparation process of the 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor is characterized by comprising the following steps: S1, adding 4-chloro-2-methylphenol and potassium hydroxide into absolute ethyl alcohol, and stirring to obtain a product 1 for later use; s2, adding the product 1 obtained in the step S1 and methyl 2-bromopropionate into anhydrous DMF, heating and refluxing for 2-3 hours at 90-100 ℃, pouring into water at 0-4 ℃, carrying out suction filtration, washing, adding into absolute ethanol, stirring, adding sodium hydroxide, heating and refluxing for 2-4 hours at 80-85 ℃, recovering to room temperature, adding dilute hydrochloric acid to adjust pH=2-3, carrying out suction filtration, and washing to obtain a product 2 for later use; s3, adding the product 2 obtained in the step S2, PEG-200, a catalyst and a polymerization inhibitor into toluene, stirring for 4-5 hours at 95-100 ℃, filtering while the mixture is hot, recovering the catalyst, taking an organic phase, adding sodium bicarbonate aqueous solution, removing water by using anhydrous sodium sulfate, and finally removing the toluene by reduced pressure distillation to obtain the 2- (4-chloro-2-methylphenoxy) -polyethylene glycol propionate.
  2. 2. The process for preparing a 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor according to claim 1, wherein in said step S1, the molar ratio of 4-chloro-2-methylphenol to potassium hydroxide is 1 (1-1.3).
  3. 3. The process for preparing a 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor according to claim 1, wherein the molar ratio of 4-chloro-2-methylphenol to methyl 2-bromopropionate is 1 (1.2-1.6).
  4. 4. The process for preparing a 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor according to claim 1, wherein the molar ratio of said 4-chloro-2-methylphenol to PEG-200 is (2-2.3): 1.
  5. 5. The process for preparing the 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor according to claim 1, wherein the mass ratio of the 4-chloro-2-methylphenol to the catalyst is 1 (0.04-0.07).
  6. 6. The process for preparing 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor according to claim 1, wherein the preparation method of the catalyst in the step S3 comprises the following steps: (1) Mixing epoxy resin with polyethylene glycol 1000 and polyethylene glycol 2000, adding diethylenetriamine, reacting for 2.5-3.5 hours at 65-75 ℃, washing, drying, soaking in tetraethoxysilane for 3-4 hours, placing in ammonia gas atmosphere at 45-55 ℃ for 11-13 hours, drying, calcining, and obtaining macroporous silica material for later use; (2) Adding the macroporous silica material in the step (1) into ZrOCl 2 aqueous solution, soaking, taking out, adding into ammonia water, soaking for 9-11h, adding span 20 and normal hexane, stirring, and calcining to obtain a product for later use; (3) And (3) adding the product obtained in the step (2) into sulfuric acid aqueous solution, soaking, taking out, drying, and calcining at 550-600 ℃ to obtain the catalyst.
  7. 7. The process for preparing the 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor according to claim 6, wherein in the step (1), the mass ratio of the epoxy resin to the polyethylene glycol 1000 to the polyethylene glycol 2000 is 1 (1.1-1.3): 0.7-1.
  8. 8. The process for preparing a 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor according to claim 6, wherein in said step (2), the ratio of the macroporous silica material to Zr element in ZrOCl 2 aqueous solution and span 20 is 1g (0.0015-0.003) mol (0.1-0.3) g.
  9. 9. The process for preparing a 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor according to claim 6, wherein in said step (3), the ratio of the product to SO 4 2- is 1g (0.013-0.02) mol.
  10. 10. The process for preparing a 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor according to any one of claims 1-9, wherein the yield of the 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester is not less than 95%.

Description

Preparation process of 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor Technical Field The invention relates to the technical field of chemical synthesis, in particular to a preparation process of a 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor. Background Along with popularization of the concepts of green buildings and sponge cities, greening forms such as planted roofs, roof gardens and the like are increasingly popularized. The strong penetrating power of the plant root system can damage the waterproof layer, so that the leakage problem is caused, and therefore, the root inhibitor becomes a key functional additive of the waterproof system. The aryloxy carboxylic acid ester root inhibitors such as 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester, (R) -2- (4-chloro-2-methylphenoxy) octyl propionate and 2-methyl-4-chloropropionic acid-polyethylene glycol ester inhibit the transportation of root system auxin through the aryloxy carboxylic acid active group, interfere with the growth of cells, have the advantages of low toxicity, environmental protection and high root inhibition efficiency, and the synthesis process thereof is widely paid attention in recent years. 2- (4-Chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester (CAS number: 144768-02-5) is widely used as a chemical root inhibitor because of its more efficient root-blocking property, biocompatibility, material compatibility and long-acting property, and it inhibits the root system from extending toward the waterproof layer by interfering with the growth metabolism of the plant root system, thereby protecting the waterproof structure. The esterification reaction in the preparation process of the 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester is critical to the influence on the yield of a target product, a catalyst is often required to be added to improve the yield, the type of the catalyst commonly used at present is concentrated sulfuric acid or p-toluenesulfonic acid, the concentrated sulfuric acid has stronger corrosiveness, the p-toluenesulfonic acid has residual hidden danger, and the industrial lasting application cannot be met. Patent CN 119241360A discloses a preparation method of (R) 2- (4-chloro-2-methylphenoxy) propionic acid iso Xin Zhizu radical agent, which comprises the following steps of carrying out condensation reaction on L-2-chloropropionic acid and o-cresol under the promotion of alkali to obtain (R) 2-methylphenoxy propionic acid, (R) 2-methylphenoxy propionic acid and isooctyl alcohol (2-ethylhexanol) are subjected to esterification reaction under the action of a catalyst to obtain (R) 2-methylphenoxy propionic acid isooctyl ester, (R) 2-methylphenoxy propionic acid isooctyl ester is chlorinated by a chlorinating agent to obtain (R) 2- (4-chloro-2-methylphenoxy) propionic acid isooctyl ester, and the obtained product has higher yield and better quality, but the catalyst in the preparation method still adopts one or more of concentrated sulfuric acid, phosphoric acid, p-toluenesulfonic acid and benzenesulfonic acid, so that the problems of corrosion or residual uneasy treatment are not solved. Therefore, there is a need in the market for a process for preparing a polyethylene glycol 2- (4-chloro-2-methylphenoxy) -propionate root inhibitor, which has the advantages of easy separation of the catalyst, low corrosiveness and excellent yield of the obtained target product. Disclosure of Invention Aiming at the problems in the prior art, the invention takes 4-chloro-2-methylphenol, potassium hydroxide, methyl 2-bromopropionate and PEG-200 as raw materials to prepare the 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor, and a catalyst is added in the esterification stage of the step S3, so that the problems of high corrosiveness or easy residue of the existing catalyst are avoided, and the prepared 2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester has the characteristic of high yield. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: the invention provides a preparation process of a2- (4-chloro-2-methylphenoxy) -propionic acid polyethylene glycol ester root inhibitor, which comprises the following steps: S1, adding 4-chloro-2-methylphenol and potassium hydroxide into absolute ethyl alcohol, and stirring to obtain a product 1 for later use; s2, adding the product 1 obtained in the step S1 and methyl 2-bromopropionate into anhydrous DMF, heating and refluxing for 2-3 hours at 90-100 ℃, pouring into water at 0-4 ℃, carrying out suction filtration, washing, adding into absolute ethanol, stirring, adding sodium hydroxide, heating and refluxing for 2-4 hours at 80-85 ℃, recovering to room temperature, adding dilute hydrochloric acid to adjust pH=2-3, carrying out suction filtration, and washing