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CN-121974803-A - Synthesis method of antioxidant GM

CN121974803ACN 121974803 ACN121974803 ACN 121974803ACN-121974803-A

Abstract

The invention discloses a synthesis method of an antioxidant GM, which comprises the following steps of (1) mixing 2-tertiary butyl-4-methylphenol with functional acidic ionic liquid under the protection of nitrogen, stirring and heating, dropwise adding acrylic anhydride, carrying out heat preservation reaction after dropwise adding, filtering and separating and washing to obtain 2-acrylic acid-2-tertiary butyl-4-methylphenyl ester, (2) mixing 2-acrylic acid-2-tertiary butyl-4-methylphenyl ester, dimethoxymethane, 2-tertiary butyl-4-methylphenol, functional acidic ionic liquid, supported phosphotungstic heteropolyacid and methanol under the protection of nitrogen, stirring and heating, carrying out reflux reaction, filtering and separating and washing, carrying out reduced pressure distillation, filtering and separating and washing while hot to obtain the antioxidant GM. The functionalized acidic ionic liquid and the supported phosphotungstic heteropoly acid adopted by the invention can promote the acquisition of the target antioxidant GM with higher purity and yield, and have better green and environment-friendly development.

Inventors

  • GUO JIAOYANG
  • ZHAO CHONGXIN

Assignees

  • 江苏极易新材料有限公司

Dates

Publication Date
20260505
Application Date
20260128

Claims (10)

  1. 1. The synthesis method of the antioxidant GM is characterized by comprising the following steps of: (1) Mixing 2-tertiary butyl-4-methylphenol with functional acidic ionic liquid under the protection of nitrogen, stirring and heating, dropwise adding acrylic anhydride, carrying out heat preservation reaction after dropwise adding, filtering and separating, and washing to obtain 2-acrylic acid-2-tertiary butyl-4-methylphenyl ester; (2) Under the protection of nitrogen, mixing 2-tert-butyl-4-methylphenyl acrylate, dimethoxymethane, 2-tert-butyl-4-methylphenol, a functional acidic ionic liquid, supported phosphotungstic heteropolyacid and methanol, stirring, heating, refluxing for reaction, filtering, separating and washing, distilling under reduced pressure, filtering, separating and washing while the mixture is hot to obtain an antioxidant GM; In the step (1) and the step (2), the functionalized acidic ionic liquid is one of sulfonic acid group functionalized ionic liquid, lewis acidic functionalized ionic liquid or double acidic functionalized ionic liquid with both sulfonic acid groups and Lewis.
  2. 2. The method for synthesizing the antioxidant GM according to claim 1, wherein in the step (1) and the step (2), the functionalized acidic ionic liquid is a sulfonic acid group functionalized ionic liquid.
  3. 3. The method for synthesizing the antioxidant GM according to claim 2, wherein the sulfonic acid group functionalized ionic liquid is one of 1-sulfonic acid propyl-3-methylimidazole bisulfate ionic liquid or 1-butylsulfonic acid-3-methylimidazole bisulfate ionic liquid.
  4. 4. The method for synthesizing the antioxidant GM according to claim 1, wherein the supported phosphotungstic heteropoly acid is MCM-41 molecular sieve supported phosphotungstic heteropoly acid catalyst or active carbon supported phosphotungstic heteropoly acid.
  5. 5. The method for synthesizing the antioxidant GM according to claim 1, wherein the reaction temperature in the step (1) is 60-70 ℃ and the reaction time is 1-1.5 h; In the step (2), the reaction temperature is 70-80 ℃ and the reaction time is 1.5-2.5 h.
  6. 6. The method for synthesizing the antioxidant GM according to claim 1 or 2, wherein in the step (1), the molar ratio of the acrylic anhydride to the 2-tert-butyl-4-methylphenol is 1-1.02:1; In the step (2), the molar ratio of the 2-tertiary butyl-4-methylphenol to the 2-tertiary butyl-4-methylphenol in the step (1) is 1:1, the molar ratio of the 2-tertiary butyl-4-methylphenol to dimethoxymethane is 1:1.05-1.25, and the dosage of the methanol is 0.7-1.5 times that of the 2-tertiary butyl-4-methylphenol.
  7. 7. The method for synthesizing the antioxidant GM according to claim 1 or 2, wherein in the step (1), the molar ratio of the amount of the functionalized acidic ionic liquid to the amount of the 2-tertiary butyl-4-methylphenol is 0.4-0.8:1; In the step (2), the molar ratio of the functionalized acidic ionic liquid to the 2-tertiary butyl-4-methylphenol is 0.05-0.1:1, and the dosage of the supported phosphotungstic heteropoly acid and the mass of the 2-tertiary butyl-4-methylphenol are 0.5-2.5%.
  8. 8. The method for synthesizing an antioxidant GM according to claim 1, wherein the step (1) is performed by washing with pure water during the filtration, separation and washing; And (3) when the solution is filtered, separated and washed while the solution is still hot, washing the solution by using a hot methanol solution or a hot methanol aqueous solution, wherein the temperature of the hot methanol solution or the hot methanol aqueous solution is 70-80 ℃.
  9. 9. The method for synthesizing the antioxidant GM according to claim 1 is characterized in that the antioxidant GM is washed by using a hot aqueous methanol solution when filtered, separated and washed while the antioxidant GM is still hot in the step (2), wherein the aqueous methanol solution is 20-40% by mass.
  10. 10. The method for synthesizing the antioxidant GM according to claim 1, wherein impurities are removed by reduced pressure distillation in both the liquid system obtained by filtering, separating and washing in the step (1) and the liquid system obtained by filtering, separating and washing in the step (2) while the liquid system is still hot, and the functionalized acidic ionic liquid is recovered.

Description

Synthesis method of antioxidant GM Technical Field The invention relates to a synthesis method of an antioxidant GM, belonging to the technical field of organic synthesis. Background The chemical name of the antioxidant GM, also called antioxidant AO-3052, is 2-acrylic acid-2- (1, 1-dimethylethyl) -6- [ [3- (1, 1-dimethylethyl) -2-hydroxy-5-methylphenyl ] methyl ] -4-tolyl ester, the chemical formula is C26H34O3, the molecular weight is 394.55, and the CAS registry number is 61167-58-6. Compared with other hindered phenol antioxidants, the antioxidant GM has excellent and stable mechanism free radical capturing capability, has the dual functions of oxidation resistance and carbon free radical capturing because of being a bisphenol monoacrylate antioxidant, has the characteristic of heat and oxygen resisting capability at high temperature, and can be applied to the fields of packaging materials, synthetic rubber, synthetic plastics and the like for food and medicine contact. The traditional method for preparing the antioxidant GM comprises the steps of step synthesis, namely, firstly synthesizing acrylic acid and phosphorus oxychloride serving as raw materials, then preparing the antioxidant GM by the reaction of the acrylic acid chloride and 2,2 '-methylenebis (4-methyl-6-tert-butylphenol), wherein the acyl halogenation process is relatively complex, the operation such as preparation and separation can cause the loss of the raw materials, the molar yield calculated by the acrylic acid is less than 40%, the product yield is low, and secondly, one-pot synthesis, such as Dufei bisphenol monoacrylate antioxidant GM, reports that 2,2' -methylenebis (4-methyl-6-tert-butylphenol), the acrylic acid and triethylamine are mixed and then dropwise added with phosphorus oxychloride, and the method has the defects that the reaction selectivity is 96%, the conversion rate is less than 93%, the yield is less than 85%, and the solid waste substances such as triethylamine hydrochloride and the like are accompanied, so that the environment is polluted, and in addition, the preparation method for preparing the antioxidant CN202310013379.9 disclosed by using 2-tert-butyl-4-methylphenol, acrylic anhydride and methylal is lower than 91%, and the catalyst contains certain concentrated sulfuric acid and can corrode equipment for a long time. Disclosure of Invention At least aiming at one problem existing in the prior art, the invention provides a synthesis method of an antioxidant GM, which takes 2-tertiary butyl-4-methylphenol, acrylic anhydride and dimethoxymethane as raw materials, adopts functionalized acidic ionic liquid and supported phosphotungstic heteropolyacid, can promote to obtain a target antioxidant GM with higher purity and yield, can also be recycled and reused, and can improve the utilization rate of the raw materials, and the synthesis method of the invention has better green and environment-friendly development. In order to achieve the purpose, the invention adopts the following technical scheme that the synthesis method of the antioxidant GM comprises the following steps: (1) Mixing 2-tertiary butyl-4-methylphenol with functional acidic ionic liquid under the protection of nitrogen, stirring and heating, dropwise adding acrylic anhydride, carrying out heat preservation reaction after dropwise adding, filtering and separating, and washing to obtain 2-acrylic acid-2-tertiary butyl-4-methylphenyl ester; (2) Under the protection of nitrogen, mixing 2-tert-butyl-4-methylphenyl acrylate, dimethoxymethane, 2-tert-butyl-4-methylphenol, functional acidic ionic liquid, supported phosphotungstic heteropolyacid and methanol, stirring, heating, refluxing for reaction, filtering, separating and washing, distilling under reduced pressure, filtering, separating and washing while the mixture is hot, and obtaining the antioxidant GM. Preferably, in step (1) and step (2), the functionalized ionic liquid is a sulfonic acid group functionalized ionic liquid, a Lewis acid functionalized ionic liquid or a dual acid functionalized ionic liquid with both sulfonic acid groups and Lewis acids, preferably a sulfonic acid group functionalized ionic liquid. Preferably, the sulfonic acid group functionalized ionic liquid is one of 1-sulfonic acid propyl-3-methylimidazole bisulfate ionic liquid or 1-butylsulfonic acid-3-methylimidazole bisulfate ionic liquid and the like. Preferably, in the step (1), the reaction temperature is 60-70 ℃ and the reaction time is 1-1.5 h. Preferably, in the step (1), the molar ratio of the acrylic anhydride to the 2-tert-butyl-4-methylphenol is 1-1.02:1. Preferably, in the step (1), the molar ratio of the acrylic anhydride to the 2-tertiary butyl-4-methylphenol is 1.005-1.015:1. Preferably, in the step (1), the molar ratio of the dosage of the functionalized acidic ionic liquid to the dosage of the 2-tertiary butyl-4-methylphenol is 0.4-0.8:1, and when the functionalized acidic ionic liquid is selected as the sul