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CN-121990915-A - Method for synthesizing adipic acid ester by butadiene hydrogen esterification

CN121990915ACN 121990915 ACN121990915 ACN 121990915ACN-121990915-A

Abstract

The invention relates to a method for synthesizing adipic acid ester by butadiene hydro-esterification. The method comprises the steps of a) dissolving a palladium catalyst, a phosphine ligand, acid and butadiene in alcohol and optional solvents in a reaction kettle, wherein the phosphine ligand is a phosphine ligand of a formula I, b) introducing carbon monoxide into the kettle for reaction, c) ending the reaction, and separating to obtain a product. The method has the characteristics of high catalytic efficiency, high product yield, high selectivity, simple operation and the like.

Inventors

  • LIU GUOSHENG
  • PENG HAIHUI
  • YANG WENCHENG
  • CHEN PINHONG

Assignees

  • 中国科学院上海有机化学研究所

Dates

Publication Date
20260508
Application Date
20241101

Claims (10)

  1. 1. A method for synthesizing adipic acid ester by hydrogen esterification of butadiene, which is characterized by comprising the following steps: a) Dissolving a palladium catalyst, a phosphine ligand, an acid and butadiene in an alcohol and optionally a solvent in a reaction kettle; b) Introducing carbon monoxide into the kettle for reaction; c) Ending the reaction and separating to obtain a product; Wherein the phosphine ligand is shown in the formula I; Wherein, the R 1 and R 4 are each independently selected from the group consisting of substituted or unsubstituted C 1-12 alkyl, substituted or unsubstituted C 3-12 cycloalkyl, substituted or unsubstituted 3-12 membered heterocycloalkyl, substituted or unsubstituted C 6-30 aryl; r 2 and R 3 are each independently a substituted or unsubstituted 5-20 membered heteroaryl; a is selected from the group consisting of: wherein R 5 、R 6 、R 7 、R 8 is independently one or more substituents selected from H, C 1-10 alkyl, C 1-10 alkoxy, C 2-10 ester, cyano, COOH, benzenesulfonyl, trialkylsilyl (wherein said alkyl is C 1-4 alkyl), nitro, C 6-30 aryl, 5-30 membered heteroaryl, or two R 5 、R 6 、R 7 、R 8 on adjacent ring atoms together with the ring atom to which they are attached form a 5-7 membered carbocyclic or heterocyclic ring, Y is one of O, NH or S; Unless otherwise specified, the substituents refer to the substitution of one or more hydrogen atoms on a group with a substituent selected from the group consisting of C 1-10 alkyl, C 1-10 alkoxy, C 2-10 ester, cyano, COOH, benzenesulfonyl, trialkylsilyl (wherein the alkyl is C 1-4 alkyl), nitro, C 6-30 aryl, and 5-30 membered heteroaryl.
  2. 2. The method of claim 1, wherein, in the ligand, R 1 and R 4 are each independently selected from the group consisting of substituted or unsubstituted C 1-4 alkyl, substituted or unsubstituted C 3-10 cycloalkyl (adamantane), phenyl; R 2 and R 3 are each independently selected from the group consisting of substituted or unsubstituted 5-10 membered heteroaryl; Unless otherwise specified, the substituents refer to the substitution of one or more hydrogen atoms on a group with a substituent selected from the group consisting of C 1-10 alkyl, C 1-10 alkoxy, C 2-10 ester, cyano, COOH, benzenesulfonyl, trialkylsilyl (wherein the alkyl is C 1-4 alkyl), nitro, C 6-30 aryl, and 5-30 membered heteroaryl.
  3. 3. The method of claim 1, wherein, in the ligand, R 1 and R 4 are each independently selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, or phenyl; R 2 and R 3 are each independently selected from the group consisting of pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyrrolyl, imidazolyl, pyrazolyl, thienyl, furyl, thiazolyl, and triazolyl; And/or R 5 、R 6 、R 7 、R 8 is independently one or more substituents on the corresponding ring selected from H, C 1-10 alkyl, C 1-10 alkoxy, C 2-10 ester, cyano, COOH, benzenesulfonyl, trialkylsilyl (wherein the alkyl is C 1-4 alkyl), nitro, C 6-10 aryl, 5-10 membered heteroaryl, or two R 5 、R 6 、R 7 、R 8 on adjacent ring atoms together with the ring atom to which they are attached form a 5-7 membered carbocyclic or heterocyclic ring.
  4. 4. The method of claim 1, wherein the ligand is selected from the group consisting of:
  5. 5. the method of claim 1, wherein the phosphine ligand is used in an amount of 0.00001 to 10% molar equivalents of the butadiene.
  6. 6. The method of claim 1, wherein when the phosphine ligand is a bisphosphine ligand (i.e., a compound of formula I), the molar ratio of the palladium catalyst to the bisphosphine ligand is 1:0.5 to 1:30.
  7. 7. The method of claim 1, wherein the alcohol is a C 1-12 alkyl alcohol, preferably selected from the group consisting of methanol, ethanol, propanol, butanol, octanol, or a combination thereof.
  8. 8. The method of claim 1, wherein the palladium catalyst is selected from the group consisting of palladium acetate, palladium trifluoroacetate, palladium quaternary valerate, palladium tetra acetonitrile tetrafluoroborate, palladium hexafluoroacetylacetonate, palladium bis (acetylacetonate), palladium tetra acetonitrile trifluoromethane sulfonate, palladium pivalate, palladium bis (dibenzylideneacetone), palladium tris (dibenzylideneacetone), palladium chloride, (1, 5-cyclooctadiene) palladium dichloride, palladium diacetonitrile dichloride, palladium dibenzonitrile dichloride, and combinations thereof.
  9. 9. The method of claim 1, wherein the acid is selected from the group consisting of perchloric acid, sulfuric acid, phosphoric acid, sulfonic acid, alkylphosphoric acid, alkylsulfonic acid, alkylcarboxylic acid, perfluoroalkylsulfonic acid, perfluoroalkylcarboxylic acid, arylsulfonic acid.
  10. 10. The method of claim 1, wherein the solvent is selected from the group consisting of an alkane solvent, a substituted aromatic solvent, an ether solvent, a ketone solvent, a nitrile solvent, an ester solvent, and combinations thereof.

Description

Method for synthesizing adipic acid ester by butadiene hydrogen esterification Technical Field The invention relates to the field of chemical production, and in particular provides a method for synthesizing adipic acid ester by butadiene hydrogen esterification. Background Adipate esters are important C-6 platform compounds, common polymeric monomers for the synthesis of nylon 66, degradable polyesters and polyurethanes. At present, the method mainly adopts cyclohexane or cyclohexene nitric acid oxidation method to produce, has long process route, harsh production conditions and high cost, and particularly generates a large amount of greenhouse gas nitrous oxide, thus a new method for synthesizing adipic acid ester in an improved way is urgently needed. The one-step synthesis of adipic acid ester by butadiene hydro-esterification has a concise and efficient route, which is one of the technical development trends of adipic acid ester production, but the process has a series of problems of low selectivity, low conversion rate and the like in the prior art, and the problems prevent the application of the process. Butadiene hydroesterification was first discovered by Brewis and Hughes et al (chem. Commun.1965,8,157) that butadiene reacted with carbon monoxide and methanol under the catalysis of bis-butylphosphine palladium iodide to produce methyl 3-pentenoate, with a reaction yield up to 68%, which was severe (> 150 ℃ C., 100-1000 atm), with low conversion and selectivity and only a monohydrogenated product, and BASF corporation had a new two-step process for synthesizing adipate using butadiene hydroesterification (US 3161672, US3876695, US 4259501) using cobalt-based metal catalysts, with the same reaction conditions being severe (> 150 ℃ C., 100-300 atm), and with a selectivity of only 60-80%, after which companies Dupont (US 4777284), shell (US 4861912, WO 00056695) have all examined the butadiene hydroesterification to produce adipate, but with no improvement in reaction conversion and selectivity. Subsequently, US4575562 discloses a method for synthesizing adipate by palladium-catalyzed hydro-esterification of butadiene using trialkyl or triarylphosphine as ligand, but with a conversion of only 50% and a selectivity of only 70%. In 2019, beller et al have made a breakthrough in the direct hydrosilation of butadiene using their own developed novel bisphosphine ligand HeMaRaphos, produced dimethyl adipate at 95% conversion and 97% selectivity at 120 ℃ and 40atm (Science 2019,366,1514-1517), and in 2021, this subject group achieved palladium-catalyzed butadiene hydrosilation to adipic diester with a simpler bidentate phosphine ligand dtbpx on the basis of previous work (Angew. Chem. Int. Ed.2021,60,9527). However, the conversion number (TON) of the above reaction is only 60000 at maximum, and the conversion frequency (TOF) is only about 1000/hr, showing that the catalytic efficiency is still to be improved. CN116925140 discloses the preparation of heterogeneous catalysts based on bidentate phosphine ligand dtbpx and their use in the preparation of adipate esters by hydro-esterification of butadiene, but the conversion number of the reaction is 50000, which is not improved. In a word, the existing palladium-catalyzed butadiene hydrogen esterification reaction condition is mild, but the conversion number and conversion frequency of the reaction are not high due to low catalytic activity, so that the industrial application of the process is affected. Disclosure of Invention The invention aims to provide a preparation method of adipic acid ester (comprising methyl ester, ethyl ester, butyl ester or octyl ester and the like), which comprises the following steps: a) Dissolving a palladium catalyst, a phosphine ligand, an acid and butadiene in an alcohol and optionally a solvent in a reaction kettle; b) Introducing carbon monoxide into the kettle for reaction; c) Ending the reaction and separating to obtain a product; Wherein the phosphine ligand is shown in the formula I; Wherein, the R 1 and R 4 are each independently selected from the group consisting of substituted or unsubstituted C 1-12 alkyl, substituted or unsubstituted C 3-12 cycloalkyl, substituted or unsubstituted 3-12 membered heterocycloalkyl, substituted or unsubstituted C 6-30 aryl; r 2 and R 3 are each independently a substituted or unsubstituted 5-20 membered heteroaryl; a is selected from the group consisting of: wherein R 5、R6、R7、R8 is independently one or more substituents selected from H, C 1-10 alkyl, C 1-10 alkoxy, C 2-10 ester, cyano, COOH, benzenesulfonyl, trialkylsilyl (wherein said alkyl is C 1-4 alkyl), nitro, C 6-30 aryl, 5-30 membered heteroaryl, or two R 5、R6、R7、R8 on adjacent ring atoms together with the ring atom to which they are attached form a 5-7 membered carbocyclic or heterocyclic ring, Y is one of O, NH or S; Unless otherwise specified, the substituents refer to the substitution of one or more hydrogen atoms on a group with