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CN-117285489-B - Recycling method and application of material containing methyl 4-acetoxybutyrate

CN117285489BCN 117285489 BCN117285489 BCN 117285489BCN-117285489-B

Abstract

The invention relates to the technical field of chemical industry, and discloses a recycling method and application of a material containing methyl 4-acetoxybutyrate. The method comprises the steps of (1) carrying out acylation reaction on a raw material containing gamma-butyrolactone and 4-acetoxymethyl butyrate and methyl acetate in the presence of sodium methoxide, carrying out azeotropic distillation at the same time to obtain a dried material containing alpha-acetyl-gamma-butyrolactone sodium salt, (2) carrying out extraction and liquid separation on the dried material after treatment to obtain a crude product of alpha-acetyl-gamma-butyrolactone, and (3) carrying out reduced pressure rectification on the crude product to separate a mixed material of gamma-butyrolactone and 4-acetoxymethyl butyrate to obtain a refined product of alpha-acetyl-gamma-butyrolactone. The method fully recycles the 4-acetoxyl methyl butyrate produced by the alpha-acetyl-gamma-butyrolactone, reduces the disposal amount of waste liquid, avoids separation of the 4-acetoxyl methyl butyrate and the gamma-butyrolactone, reduces energy loss, and the prepared alpha-acetyl-gamma-butyrolactone has higher yield and purity.

Inventors

  • YUAN YUKUN
  • LI QUANGUO
  • WANG QING
  • Ju Anting
  • ZHENG TAO
  • GUO GUANAN

Assignees

  • 江西天新药业股份有限公司

Dates

Publication Date
20260508
Application Date
20230811

Claims (12)

  1. 1. A process for preparing α -acetyl- γ -butyrolactone, comprising the steps of: (1) In the presence of sodium methoxide, carrying out acylation reaction on a raw material containing gamma-butyrolactone and 4-acetoxymethyl butyrate and methyl acetate, and simultaneously carrying out azeotropic distillation to recover part of methyl acetate and generated methanol to obtain a dried material containing alpha-acetyl-gamma-butyrolactone sodium salt; In the raw materials, the mass fraction of the 4-acetoxy methyl butyrate accounting for the total amount of the gamma-butyrolactone and the 4-acetoxy methyl butyrate is 2-10%, and the mole ratio of the total amount of the 4-acetoxy methyl butyrate and the gamma-butyrolactone to the methyl acetate and the sodium methoxide is 1 (2-15) (0.5-2); (2) Extracting and separating the dried material after treatment to obtain a crude product of alpha-acetyl-gamma-butyrolactone; the treatment process comprises diluting the dry material with water, and neutralizing with dilute sulfuric acid; (3) And (3) carrying out first reduced pressure rectification on the crude product at 105-110 ℃, separating unreacted 4-acetoxymethyl butyrate and gamma-butyrolactone mixture, and carrying out second reduced pressure rectification on the obtained concentrated solution at 120-160 ℃ to obtain alpha-acetyl-gamma-butyrolactone.
  2. 2. The process according to claim 1, wherein the molar ratio of the total amount of methyl 4-acetoxybutyrate and gamma-butyrolactone, methyl acetate and sodium methoxide is 1 (3-12): 1-1.5.
  3. 3. The process of claim 1, wherein the temperature of the acylation reaction is 60-100 ℃; And/or the pressure of the acylation reaction is 0.01-0.6MPa; and/or the acylation reaction is carried out for 1-30h.
  4. 4. A process according to claim 3, wherein the temperature of the acylation reaction is 80-90 ℃; and/or the pressure of the acylation reaction is 0.1-0.3MPa; And/or the acylation reaction is carried out for 3-15h.
  5. 5. The process according to claim 1, wherein the reflux ratio during the azeotropic distillation is (3-4): 1.
  6. 6. The method of claim 1, wherein the extractant used in the extraction of the liquid fraction is selected from at least one of benzene homologs, carbon tetrachloride, hexane, cyclohexane and petroleum ether; the benzene homologue is a compound represented by the general formula C n H 2n-6 , wherein n >6.
  7. 7. The method of claim 6, wherein the benzene homolog is at least one of toluene, ethylbenzene, and xylenes.
  8. 8. The method of claim 7, wherein the benzene homolog is toluene.
  9. 9. The method according to claim 6, wherein the mass ratio of the extractant to the mixture of methyl 4-acetoxybutyrate and gamma-butyrolactone is 0.5-5:1.
  10. 10. The method of claim 9, wherein the mass ratio of the extractant to the mixture of methyl 4-acetoxybutyrate and gamma-butyrolactone is 2.5:1.
  11. 11. The process of claim 1, wherein the temperature of the extraction fraction is 0-5 ℃.
  12. 12. The method of claim 1, wherein the pressure of the first reduced pressure distillation is 500-1000Pa and the pressure of the second reduced pressure distillation is 100-500Pa.

Description

Recycling method and application of material containing methyl 4-acetoxybutyrate Technical Field The invention relates to the technical field of chemical industry, in particular to a recycling method and application of a material containing methyl 4-acetoxybutyrate. Background The alpha-acetyl-gamma-butyrolactone is an important organic chemical raw material and is an intermediate for preparing vitamin B 1 and pesticides. At present, the main process route for synthesizing alpha-acetyl-gamma-butyrolactone mainly uses gamma-butyrolactone and methyl (or ethyl) acetate as starting materials, and takes claisen condensation under the existence of strong base substances (metal sodium, metal potassium, sodium alkoxide, sodium amide and the like) to prepare the target product. Because the metal sodium participates in the reaction too strongly, potential safety hazards such as flushing, burning, explosion and the like exist in the production, and the synthesis of target products by the acylation reaction of acetic ester and gamma-butyrolactone by replacing sodium alkoxide with the metal sodium becomes a research hot spot in recent years. CN103304519a discloses a process for preparing α -acetyl- γ -butyrolactone, wherein the reaction material can be recovered, the γ -butyrolactone (I), methyl acetate (II), sodium methoxide and inert solvent are acylated, unreacted methyl acetate, by-product methanol and a small amount of inert solvent are separated, and the α -acetyl- γ -butyrolactone pure product is obtained through neutralization, desolventizing and rectification. However, the phosphoric acid is used as an acidifying agent, so that the cost is high, and the product yield is low. CN108129423a discloses a method for preparing α -acetyl- γ -butyrolactone, solid sodium methoxide is used as catalyst, γ -butyrolactone and ethyl acetate are used as starting materials, and the α -acetyl- γ -butyrolactone is obtained by performing acetylation reaction, washing, neutralization, filtration, and reduced pressure distillation. However, because ethyl acetate is used as an acylating agent, the system contains mixed alcohol of methanol and ethanol, and the recovery difficulty is high. In the prior art, although sodium methoxide is disclosed as a catalyst for preparing the alpha-acetyl-gamma-butyrolactone, the yield is low and is less than 85%, and the 4-acetoxymethyl butyrate impurities are generated. The formation of methyl 4-acetoxybutyrate impurity proceeds mainly via the following equation: because of the equilibrium, methyl 4-acetoxyformate is always present in the system, accounting for about 2% -3% of the alpha-acetyl-gamma-butyrolactone mass ratio. The impurity is enriched in the pre-boiling of the unreacted raw material gamma-butyrolactone in the rectification separation process, and if the impurity can be recycled, the yield of the alpha-acetyl-gamma-butyrolactone and the utilization rate of the raw material gamma-butyrolactone can be further improved. Therefore, it is of great importance to research and develop a process for converting methyl 4-acetoxybutyrate to α -acetyl- γ -butyrolactone. Disclosure of Invention Aiming at the problem of 4-acetoxymethyl butyrate impurity existing in the production of alpha-acetyl-gamma-butyrolactone in the prior art, the invention provides a recycling method and application of a material containing 4-acetoxymethyl butyrate, which are used for improving the utilization rate of raw materials and the yield of alpha-acetyl-gamma-butyrolactone. In order to achieve the above object, a first aspect of the present invention provides a method for recycling a material containing methyl 4-acetoxybutyrate, wherein the method comprises the steps of: (1) In the presence of sodium methoxide, carrying out acylation reaction on a raw material containing gamma-butyrolactone and 4-acetoxymethyl butyrate and methyl acetate, and simultaneously carrying out azeotropic distillation to recover part of methyl acetate and generated methanol to obtain a dried material containing alpha-acetyl-gamma-butyrolactone sodium salt; (2) Extracting and separating the dried material after treatment to obtain a crude product of alpha-acetyl-gamma-butyrolactone; (3) And (3) carrying out reduced pressure rectification on the crude product, and separating a mixture of gamma-butyrolactone and methyl 4-acetoxybutyrate to obtain a refined product of alpha-acetyl-gamma-butyrolactone. In a second aspect the invention provides the use of a process as described hereinbefore in the preparation of α -acetyl- γ -butyrolactone. According to the technical scheme, the alpha-acetyl-gamma-butyrolactone is prepared by taking the mixture of the methyl 4-acetoxybutyrate and the gamma-butyrolactone as the raw materials, the methyl 4-acetoxybutyrate can be recycled, the increase of waste liquid amount in the production process is reduced, the energy consumption and time for separating the methyl 4-acetoxybutyrate and the gamma-butyrolactone are