A method for synthesizing a bis- trimellitic anhydride diphenyl ester or bis-trimellitic anhydride diol ester

Abstract

The application discloses a synthesis method of a trimellitic anhydride binary phenol ester or a trimellitic anhydride binary alcohol ester in the field of organic synthesis chemical industry, and comprises the following steps: firstly, stirring binary phenol / alcohol and anhydrous solvent to be fully dissolved, then adding N-alkyl imidazole chloride as a catalyst to obtain solution A1; secondly, stirring chlorinated trimellitic anhydride and anhydrous solvent to be fully dissolved to obtain solution A2; then, slowly adding solution A1 into solution A2 under the conditions of 0-5 DEG C and N2 protection, and preparing reaction liquid A3 through a catalytic esterification reaction; and finally, centrifuging reaction liquid A3, stirring the solid into saturated sodium bicarbonate solution to be neutral, reducing pressure and filtering, and drying the filter cake to obtain high-purity trimellitic anhydride hydroquinone ester. The method has the effect of efficiently catalyzing the esterification of chlorinated trimellitic anhydride and binary phenol / alcohol, the residual solvent in the target product can be easily removed, the next step of polymerization is not affected, the production cost is low, and the method has better economy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic chemical synthesis. In particular, it relates to a synthesis method of trimellitic anhydride dihydric phenol ester or dihydric alcohol ester. BACKGROUND

[0002] Trimellitic anhydride chloride (TMAC) is a very important carboxylic acid derivative, which can mainly undergo hydrolysis, alcoholysis, ammonolysis (aminolysis), reaction with organic metal reagents, reduction reaction, and hydrogen halide reaction. TMAC, as an important composite resin and polyimide monomer synthesis raw material, can be used to synthesize dental composite resin materials; esterification with different diphenol monomers can prepare polyimide (PI) monomer ester anhydride; polymerization with different diamine monomers can prepare polyamide-imide (PAI) special engineering plastics. TMAC is a block crystal, with a melting point of 66-70℃, a boiling point of 391.4℃, and a flash point of 186.3℃. It is easy to absorb moisture and should avoid contact with humid air.

[0003] Phenols can be divided into monohydric phenol, dihydric phenol and polyhydric phenol according to the number of hydroxyl groups directly connected to the aromatic ring. Dihydric phenol is a phenol containing two phenolic hydroxyl groups in the molecule. Although phenol can undergo two types of reactions, C-O bond and O-H bond cleavage, the C-O bond is very strong and not easy to break due to p-π conjugation effect. However, the O-H bond is easy to break because the negative charge in the generated phenoxide anion can be delocalized and stabilized. The benzene ring on the phenol is more prone to electrophilic substitution reaction than benzene due to the above-mentioned conjugation effect. Dihydric phenol includes hydroquinone (HQ), resorcinol, tertiary butyl hydroquinone (TBHQ), 2,6-naphthalene diol (2,6-DON), 2,7-naphthalene diol (2,7-DON), bisphenol A (BPA), hydrogenated bisphenol A (HBPA), 1,1-bis(4-hydroxyphenyl)pentane, etc.

[0004] Dihydric alcohol refers to an alcohol with two hydroxyl groups (-OH). Dihydric alcohol includes ethylene glycol (EG), 1,3-propanediol (PDO), 1,4-butanediol (BDO), 1,5-pentanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, etc.

[0005] The structural formula of dihydric phenol / alcohol is as follows:

[0006]

[0007] A series of polyimide dianhydride monomers of ester anhydride of endo-trimellitic anhydride binary phenol or binary glycol ester (referred to as ester anhydride) belong to a class of compounds of dianhydride. They include endo-trimellitic anhydride hydroquinone ester (TAHQ), endo-trimellitic anhydride resorcinol ester, endo-trimellitic anhydride (2,6-naphthalene diol) ester, endo-trimellitic anhydride (2,7-naphthalene diol) ester, endo-trimellitic anhydride bisphenol A ester, endo-trimellitic anhydride hydrogenated bisphenol A ester, endo-trimellitic anhydride ethylene glycol ester (TMEG), endo-trimellitic anhydride propylene glycol ester, endo-trimellitic anhydride butanediol ester, endo-trimellitic anhydride pentanediol ester, endo-trimellitic anhydride p-cyclohexanediol ester, endo-trimellitic anhydride m-cyclohexanediol ester, and the like.

[0008] Endo-trimellitic anhydride binary phenol ester is mainly used for producing polyimide (PI) film (including transparent film) and resin, 5G modified polyimide (MPI) antenna material, microwave millimeter wave liquid crystal material, high-end high polymer polyester resin curing agent, high-temperature-resistant epoxy resin curing agent, high-end powder coating matting agent, high-grade electrical insulation material, and the like.

[0009] Endo-trimellitic anhydride binary glycol ester is an important chemical raw material. When it reacts with epoxy resin, it can be used to prepare adhesives and coatings with good heat resistance; similarly, when it reacts with alcohol, it can be used to prepare polyesters with good heat resistance. Unsaturated polyesters prepared therefrom can be processed into various products such as, for example, molding plastics, glass steel, and the like; recently, copolyimide films prepared therefrom have been widely used in soft printed circuit boards and copper laminated boards due to their good adhesion to copper, opening up new fields for polyimide.

[0010] A series of ester anhydride structures are as follows:

[0011]

[0012]

[0013]

[0014] At present, the main method for synthesizing ester anhydride is acyl chloride esterification. For example, first, trimellitic anhydride is reacted with dimethyl sulfoxide in the presence of a catalyst at a certain temperature to obtain chlorinated trimellitic anhydride. Then, esterification is carried out with hydroquinone to obtain endo-trimellitic anhydride hydroquinone ester.

[0015] CN102167827B patent discloses a kind of based on trimellitic anhydride optical property thermotropic liquid crystal polyester imide and its preparation method and application.The molecular main chain of this kind of optical polymer contains chiral amino acid unit, by solution direct condensation method from three or more than three monomers, including trimellitic anhydride type dicarboxylic acid containing amino acid chiral source, aromatic dihydric phenol and hydroxy acid etc.monomer copolymerization is obtained.The dicarboxylic acid monomer containing amino acid chiral source is obtained by reaction of amino acid and trimellitic anhydride.The polymer obtained by the present application has optical property and thermotropic liquid crystal property, specific optical rotation-1~-10°·cm 3 ·dm -1 ·g -1 , also has good solvent resistance, only dissolved in trifluoroacetic acid and phenol: four chloroethane=3:2 Mixed solvent, and has excellent thermal stability, and 5% weight loss temperature generally can reach 350 DEG C.The polymer obtained by the present application shows good application prospect in the field of chiral recognition and enantiomer resolution, chiral catalyst, liquid crystal, biological medicine, optical switch and nonlinear optics.

[0016] CN115301287A provides a preparation method of high-purity p-phenylene-bisphenyl trimellitate dianhydride, comprising the following steps: mixing trimellitic anhydride acyl chloride, p-dihydroxybenzene, a catalyst and a first solvent, heating and reacting to obtain a first reaction liquid, the catalyst is prepared by one-pot method from formaldehyde, dialkylamine and ion resin; the catalyst is removed by filtering the first reaction liquid, the filtrate obtained after filtering is cooled and filtered, the filter cake is washed with a second solvent, and vacuum drying is performed to obtain a crude product containing p-phenylene-bisphenyl trimellitate dianhydride. The preparation method of high-purity p-phenylene-bisphenyl trimellitate dianhydride has the advantages of short reaction steps, mild conditions, simple post-treatment operation, high yield, simple and effective refining method, and high product purity. The product yield synthesized by the method is as high as 98%, the purity is more than 99.5%, the highest can reach 99.95%, the colority is less than 2, and it is suitable for industrial production.

[0017] The patent with publication number WO2010013620(A1) discloses a preparation method of p-phenylene-bisphenyl trimellitate dianhydride, using trimellitic anhydride acyl chloride and p-dihydroxybenzene as main raw materials, pyridine as catalyst, and N,N-dimethylformamide as solvent. The purity of the target product obtained by the reaction is 95.30%. The above method has the problems of low purity of the target product, large solvent consumption, and difficult recovery and reuse of the solvent. The N,N-dimethylformamide solvent residue in the target product is difficult to remove, which affects the next polymerization.

[0018] The disadvantages of the existing synthesis method of bis-trimellitic anhydride p-dihydroxybenzene ester are that multiple catalysts and multiple solvents are used, the amount of catalyst used is also large, the by-products need to be separated, and the equipment requirements are high. SUMMARY

[0019] The purpose of the present application is to provide a synthesis method of bis- trimellitic anhydride dihydric phenol ester or dihydric alcohol ester, which has the effect of high-efficiency catalytic esterification of chlorinated trimellitic anhydride and dihydric phenol / alcohol, the solvent residue in the target product is easy to remove and does not affect the next step of polymerization, and the production cost is low, which has better economic efficiency.

[0020] The purpose of the present application is achieved by a synthesis method of bis-trimellitic anhydride dihydric phenol ester or dihydric alcohol ester, which comprises the following steps:

[0021] (1) stirring dihydric phenol / alcohol and anhydrous solvent to full dissolution, then adding a catalyst to obtain solution A1; the catalyst is N-alkyl imidazole, and the alkyl group can include one of methyl, ethyl, propyl, butyl and pentyl;

[0022] (2) stirring chlorinated trimellitic anhydride and anhydrous solvent to full dissolution to obtain solution A2;

[0023] (3) under the condition of 0-5℃ and N2 protection, slowly adding solution A1 to solution A2 to obtain reaction solution A3 through catalytic esterification reaction; the molar ratio of chlorinated trimellitic anhydride, dihydric phenol / alcohol and catalyst in the reaction raw material is 2:1.02-1.05:0.3-0.5;

[0024] (4) after centrifugal separation of reaction solution A3, saturated sodium bicarbonate solution is added to the obtained solid, stirred to neutral, and the filter cake is dried under reduced pressure to obtain high-purity bis-trimellitic anhydride dihydric phenol ester or dihydric alcohol ester.

[0025] Further, the dihydric phenol / alcohol raw material includes one of hydroquinone, resorcinol, 2,6-naphthalene diol, 2,7-naphthalene diol, bisphenol A, hydrogenated bisphenol A, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-cyclohexanediol and 1,4-cyclohexanediol.

[0026] The anhydrous solvent in the above-mentioned step (1) and step (2) is tetrahydrofuran, acetone or acetonitrile.

[0027] The present application preferably uses hydroquinone as the raw material, and the mass ratio of hydroquinone to anhydrous solvent in step (1) is 1:(4-9); and the mass ratio of chlorinated trimellitic anhydride to anhydrous solvent in step (2) is 1:2.5-5.5.

[0028] Further, in step (3), the catalytic esterification reaction is controlled at 0-5℃.

[0029] The present application researches a kind of high-efficiency catalyst on the basis of alcohol acid esterification reaction, R-MImCl, and its structural formula is as follows:

[0030]

[0031] The catalyst has the advantages of high activity, good selectivity, mild reaction conditions, simple post-treatment, no corrosion, reusability, etc., and solves the above problems well. Residual solvent in the target product is easy to remove and does not affect the next step of polymerization. The production cost is low, and the method has better economy. The method provides technical support for large-scale industrial production of pyrogallol ester of trimellitic anhydride.

[0032] The reaction raw materials are divided into three steps: activation of acyl chloride of trimellitic anhydride, addition reaction of acyl chloride amine salt and hydroxyl of phenol (or alcohol), and elimination reaction.

[0033] The acyl chloride of trimellitic anhydride is activated by a basic catalyst to form an electrophilic acyl chloride amine salt. The hydrogen ion of the hydroxyl group is replaced by the chloride ion in the acyl chloride amine salt to form an acyloxy group. The chloride ion in the ester undergoes an elimination reaction with a nucleophile to finally generate an ester anhydride, and an amine hydrochloride salt is generated as a byproduct. DETAILED DESCRIPTION

[0034] The application will be further described below in conjunction with examples, but the scope of protection claimed by the application includes and is not limited to the scope expressed in the examples.

[0035] Example 1:

[0036] (1) 22.63 g (0.2 mol) of pyrogallol and 85 g of anhydrous tetrahydrofuran were stirred until completely dissolved, and then 8.73 g (0.06 mol) of N-propylimidazole chloride salt was added to obtain solution A1; 90.52 g (0.4 mol) of chlorinated trimellitic anhydride and 202 g of anhydrous tetrahydrofuran were stirred until completely dissolved to obtain solution A2;

[0037] (2) Under the condition of 0°C and N2 protection, solution A1 was slowly added (2 drops or less per second, preferably 1 drop per second) to solution A2 to obtain reaction solution A3 through esterification reaction;

[0038] (3) The reaction solution A3 was centrifuged, and the solid was added to saturated sodium bicarbonate solution until neutral. The filter cake was dried to obtain high-purity pyrogallol ester of trimellitic anhydride. The results were tested by LC method.

[0039] Example 2:

[0040] The "9.55 g of catalyst was added again", and the others were the same as in Example 1.

[0041] Example 3:

[0042] The "11.94 g of catalyst was added again", and the others were the same as in Example 1.

[0043] Comparative Example 1:

[0044] Instead of "add 14.32 g of catalyst", the other is the same as Example 1.

[0045] Comparative Example 2:

[0046] Instead of "add 14.32 g of catalyst", the other is the same as Example 1.

[0047] Table 1. Effect of catalyst amount on product purity and yield

[0048]

[0049] According to the comparison results in Table 1, with the increase of the amount of N-propyl imidazole chloride salt catalyst, the product purity and yield first increase and then decrease. The molar ratio of chlorinated trimellitic anhydride: catalyst is 2:0.3-0.5, preferably 2:0.4.

[0050] Example 4:

[0051] Instead of "stir 22.85 g of hydroquinone and 85 g of anhydrous tetrahydrofuran until completely dissolved", the other is the same as Example 2.

[0052] Example 5:

[0053] Instead of "stir 23.07 g of hydroquinone and 85 g of anhydrous tetrahydrofuran until completely dissolved", the other is the same as Example 2.

[0054] Example 6:

[0055] Instead of "stir 23.30 g of hydroquinone and 85 g of anhydrous tetrahydrofuran until completely dissolved", the other is the same as Example 2.

[0056] Comparative Example 3:

[0057] Instead of "stir 23.52 g of hydroquinone and 85 g of anhydrous tetrahydrofuran until completely dissolved", the other is the same as Example 2.

[0058] Comparative Example 4:

[0059] Instead of "stir 22.19 g of hydroquinone and 85 g of anhydrous tetrahydrofuran until completely dissolved", the other is the same as Example 2.

[0060] Table 2. Effect of hydroquinone amount on product purity and yield

[0061] Item p-dihydroxybenzene g Purity % Yield % Example 4 22.85 99.92 98.58 Example 5 23.07 99.96 98.86 Example 6 23.30 99.94 98.85 Comparative Example 3 23.52 98.90 96.87 Comparative Example 4 22.19 98.79 95.68

[0062] According to the comparison results in Table 2, with the increase of the amount of hydroquinone, the product purity and yield first increase and then decrease. The molar ratio of chlorinated trimellitic anhydride: hydroquinone is 2:1.02-1.05, preferably 2:1.04.

[0063] Example 7:

[0064] Use "at 1 °C and under N2protection" instead, and the rest is the same as Example 5.

[0065] Example 8:

[0066] Use "at 3 °C and under N2protection" instead, and the rest is the same as Example 5.

[0067] Example 9:

[0068] Use "at 5 °C and under N2protection" instead, and the rest is the same as Example 5.

[0069] Comparative Example 5:

[0070] Use "at 7 °C and under N2protection" instead, and the rest is the same as Example 5.

[0071] Comparative Example 6:

[0072] Use "at -2 °C and under N2protection" instead, and the rest is the same as Example 5.

[0073] Table 3 Influence of reaction temperature on product purity and yield

[0074] Item Reaction temperature °C Purity % Yield % Example 7 1 99.74 98.88 Example 8 3 99.98 98.83 Example 9 5 98.16 97.45 Comparative Example 5 7 98.11 96.74 Comparative Example 6 -2 99.23 98.76

[0075] According to the comparison results in Table 3, with the increase of reaction temperature, the product purity and yield first increase and then decrease. The reaction temperature is controlled at 0-5 °C, preferably 3 °C.

[0076] Example 10:

[0077] Use "stir 23.07 g of hydroquinone and 115.37 g of anhydrous tetrahydrofuran until completely dissolved" instead, and the rest is the same as Example 5.

[0078] Example 11:

[0079] Use "stir 23.07 g of hydroquinone and 161.52 g of anhydrous tetrahydrofuran until completely dissolved" instead, and the rest is the same as Example 5.

[0080] Example 12:

[0081] Use "stir 23.07 g of hydroquinone and 207.66 g of anhydrous tetrahydrofuran until completely dissolved" instead, and the rest is the same as Example 5.

[0082] Comparative Example 7:

[0083] Use "stir 23.07 g of hydroquinone and 230.74 g of anhydrous tetrahydrofuran until completely dissolved" instead, and the rest is the same as Example 5.

[0084] Comparative Example 8:

[0085] Instead of "stirring 23.07 g of hydroquinone and 69.22 g of anhydrous tetrahydrofuran to a solid-liquid mixture", the other is the same as Example 5.

[0086] Table 4 Comparison table of the effect of the amount of hydroquinone solvent on product purity and yield

[0087] Item Tetrahydrofuran Purity % Yield % Example 10 115.37 99.78 98.63 Example 11 161.52 99.99 98.87 Example 12 207.66 99.85 98.66 Comparative Example 7 230.74 99.83 98.92 Comparative Example 8 69.22 95.24 90.61

[0088] According to the comparison results in Table 4, as the solvent tetrahydrofuran of hydroquinone increases, the product purity and yield first increase and then decrease. The preferred is chlorinated trimellitic anhydride: tetrahydrofuran = 1:7.

[0089] Example 13:

[0090] Instead of "stirring 23.07 g of hydroquinone and 69.22 g of anhydrous tetrahydrofuran to a solid-liquid mixture", the other is the same as Example 5.

[0091] Example 14:

[0092] Instead of "stirring 23.07 g of hydroquinone and 69.22 g of anhydrous tetrahydrofuran to a solid-liquid mixture", the other is the same as Example 5.

[0093] Example 15:

[0094] Instead of "stirring 23.07 g of hydroquinone and 69.22 g of anhydrous tetrahydrofuran to a solid-liquid mixture", the other is the same as Example 5.

[0095] Comparative Example 9:

[0096] Instead of "stirring 23.07 g of hydroquinone and 69.22 g of anhydrous tetrahydrofuran to a solid-liquid mixture", the other is the same as Example 5.

[0097] Comparative Example 10:

[0098] Instead of "stirring 23.07 g of hydroquinone and 69.22 g of anhydrous tetrahydrofuran to a solid-liquid mixture", the other is the same as Example 5.

[0099] Table 5 Comparison table of the effect of the amount of chlorinated trimellitic anhydride solvent on product purity and yield

[0100] Item Tetrahydrofuran Purity % Yield % Example 13 296.77 99.92 98.63 Example 14 381.56 99.99 98.92 Example 15 466.35 99.81 98.64 Comparative Example 9 551.14 99.73 98.45 Comparative Example 10 127.19 94.36 91.58

[0101] According to the comparison results in Table 5, as the solvent tetrahydrofuran of chlorinated trimellitic anhydride increases, the product purity and yield first increase and then decrease. The preferred is chlorinated trimellitic anhydride: tetrahydrofuran = 1:4.5.

[0102] Example 16:

[0103] Instead of "stirring 84.79 g of trimellitic acid chloride and 381.56 g of anhydrous acetone until completely dissolved", other operations are the same as those in Example 14.

[0104] Example 17:

[0105] Instead of "stirring 84.79 g of trimellitic acid chloride and 381.56 g of anhydrous acetone until completely dissolved", other operations are the same as those in Example 14.

[0106] Comparative Example 11:

[0107] Instead of "stirring 84.79 g of trimellitic acid chloride and 381.56 g of anhydrous acetone until completely dissolved", other operations are the same as those in Example 14.

[0108] Comparative Example 12:

[0109] Instead of "stirring 84.79 g of trimellitic acid chloride and 381.56 g of anhydrous acetone until completely dissolved", other operations are the same as those in Example 14.

[0110] Table 6 Influence of solvent type on product purity and yield

[0111] Item Solvent Purity % Yield % Example 16 Acetone 99.71 98.74 Example 17 Acetonitrile 99.75 98.86 Comparative Example 11 DMF 94.52 90.69 Comparative Example 12 DMSO 93.83 90.45

[0112] According to the comparison results in Table 6, the product purity and yield of tetrahydrofuran, acetone and acetonitrile are better than those of DMF and DMSO, and tetrahydrofuran is preferred.

[0113] Example 18:

[0114] Instead of "adding 9.55 g of N-methylimidazole chloride salt", other operations are the same as those in Example 14.

[0115] Example 19:

[0116] Instead of "adding 9.55 g of N-methylimidazole chloride salt", other operations are the same as those in Example 14.

[0117] Example 20:

[0118] Instead of "adding 9.55 g of N-methylimidazole chloride salt", other operations are the same as those in Example 14.

[0119] Example 21:

[0120] Instead of "adding 9.55 g of N-methylimidazole chloride salt", other operations are the same as those in Example 14.

[0121] Comparative Example 13:

[0122] Instead of "adding 9.55 g of N-methylimidazole chloride salt", other operations are the same as those in Example 14.

[0123] Comparative Example 14:

[0124] Example 14 was repeated, except that "9.55 g of imidazole chloride salt was added again".

[0125] Table 7 Effect of catalyst type on product purity and yield

[0126] Item Catalyst Purity % Yield % Example 16 N-methylimidazole chloride salt 99.93 98.68 Example 17 N-ethylimidazole chloride salt 99.97 98.79 Example 18 N-butylimidazole chloride salt 99.95 98.81 Example 19 N-pentylimidazole chloride salt 99.61 98.05 Comparative Example 13 N-hexylimidazole chloride salt 98.12 97.13 Comparative Example 14 Imidazole chloride salt 96.01 95.47

[0127] From the results in Table 7, as the length of the N-alkyl chain in the catalyst increases, the product purity and yield first increase and then decrease. N-Propylimidazole chloride salt is preferred.

[0128] Example 22:

[0129] Example 14 was repeated, except that "23.07 g of resorcinol and 161.52 g of anhydrous tetrahydrofuran were stirred until dissolved".

[0130] Example 23:

[0131] Example 14 was repeated, except that "33.64 g of 2,6-naphthol and 161.52 g of anhydrous tetrahydrofuran were stirred until dissolved".

[0132] Example 24:

[0133] Example 14 was repeated, except that "33.64 g of 2,7-naphthol and 161.52 g of anhydrous tetrahydrofuran were stirred until dissolved".

[0134] Example 25:

[0135] Example 14 was repeated, except that "47.94 g of bisphenol A and 161.52 g of anhydrous tetrahydrofuran were stirred until dissolved".

[0136] Example 26:

[0137] Example 14 was repeated, except that "50.48 g of hydrogenated bisphenol A and 161.52 g of anhydrous tetrahydrofuran were stirred until dissolved".

[0138] Example 27:

[0139] Example 14 was repeated, except that "13.03 g of ethylene glycol was added to 9.55 g of N-propylimidazole chloride salt, stirred, and solution Al was obtained".

[0140] Example 28:

[0141] Example 14 was repeated, except that "15.98 g of 1,3-propanediol was added to 9.55 g of N-propylimidazole chloride salt, stirred, and solution Al was obtained".

[0142] Example 29:

[0143] Instead of "adding 18.90 g of 1,4-butanediol to 9.55 g of N-propylimidazole chloride salt, stirring to obtain solution Al", the other steps are the same as those in Example 14.

[0144] Example 30:

[0145] Instead of "adding 21.87 g of 1,5-pentanediol to 9.55 g of N-propylimidazole chloride salt, stirring to obtain solution Al", the other steps are the same as those in Example 14.

[0146] Example 31:

[0147] Instead of "adding 24.39 g of 1,3-cyclohexanediol to 9.55 g of N-propylimidazole chloride salt, stirring to obtain solution Al", the other steps are the same as those in Example 14.

[0148] Example 32:

[0149] Instead of "adding 24.39 g of 1,4-cyclohexanediol to 9.55 g of N-propylimidazole chloride salt, stirring to obtain solution Al", the other steps are the same as those in Example 14.

[0150] Table 8 Comparison table of the influence of phenol / alcohol species on product purity and yield

[0151] Item Phenol / alcohol Phenol / alcohol g Purity % Yield % Example 22 m-dihydroxybenzene 23.07 99.95 98.71 Example 23 2,6-naphthalenediol 33.64 99.65 98.24 Example 24 2,7-naphthalenediol 33.64 99.72 98.33 Example 25 Bisphenol A 47.94 99.91 98.42 Example 26 Hydrogenated bisphenol A 50.48 99.66 98.31 Example 27 Ethylene glycol 13.03 99.43 98.80 Example 28 1,3-propanediol 15.98 99.28 98.69 Example 29 1,4-butanediol 18.90 99.37 98.58 Example 30 1,5-pentanediol 21.87 99.29 98.35 Example 31 1,3-cyclohexanediol 24.39 99.74 98.47 Example 32 1,4-cyclohexanediol 24.39 99.51 98.36

[0152] According to the comparison results in Table 4, the ester anhydride with a purity of ≥99.2% and a yield of ≥98.3% is prepared by using different dihydric phenols / alcohols. It is proved that the catalytic synthesis method of the present application is reliable and effective.

[0153] The present application is not limited to the above examples. Based on the technical solutions disclosed in the present application, those skilled in the art can make some substitutions and modifications to some technical features without creative labor according to the disclosed technical content, and these substitutions and modifications are all within the protection scope of the present application.

Claims

1. A method for synthesizing a bis- trimellitic anhydride diphenyl ester or bis-trimellitic anhydride diol ester, characterized by The method comprises the following steps: (1) stirring the binary phenol / alcohol and anhydrous solvent until completely dissolved, then adding a catalyst to obtain solution A1; the catalyst is N-alkyl imidazole chloride salt, the alkyl group is one of methyl, ethyl, propyl, butyl and pentyl; the anhydrous solvent is tetrahydrofuran, acetone or acetonitrile; (2) stirring the chlorinated trimellitic anhydride and anhydrous solvent until completely dissolved to obtain solution A2; the anhydrous solvent is the same as that in step (1); (3) slowly adding solution A1 to solution A2 under the conditions of 0-5℃ and N2 protection to obtain reaction solution A3 through catalytic esterification; the molar ratio of the chlorinated trimellitic anhydride, binary phenol / alcohol and catalyst in the reaction raw material is 2:1.02-1.05:0.3-0.5; (4) after centrifugal separation of the reaction solution A3, saturated sodium bicarbonate solution is added to the obtained solid, stirred until neutral, then reduced pressure filtration and drying of the filter cake to obtain high-purity binary phenol ester or binary alcohol ester of trimellitic anhydride.

2. The method of synthesizing a dipentaerythritol dihydric phenol ester or dihydric alcohol ester according to claim 1, characterized by, The binary phenol / alcohol raw material includes one of hydroquinone, resorcinol, 2,6-naphthalene diol, 2,7-naphthalene diol, bisphenol A, hydrogenated bisphenol A, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-cyclohexanediol and 1,4-cyclohexanediol.

3. The method for synthesizing a bis(p-p-phenylene) trihydride diphenol ester or diol ester according to claim 2, characterized in that, When hydroquinone is used as the raw material, the mass ratio of hydroquinone to anhydrous solvent in step (1) is 1:(4-9); the mass ratio of the chlorinated trimellitic anhydride to anhydrous solvent in step (2) is 1:2.5-5.

5.

4. A process for the synthesis of a bis-trimellitate di-phenol ester or di-glycol ester according to any one of claims 1 to 3, characterized in that, In step (3), the catalytic esterification reaction is controlled at 0-5℃.

Images