Heterocyclic dibasic acids containing nonpolar hydrophobic groups, and methods of making and using the same

Abstract

The application provides a heterocyclic dibasic acid containing a non-polar hydrophobic group and a preparation method and application thereof. The heterocyclic dibasic acid has a structure shown in formula 1, wherein Y is a substituted or unsubstituted heterocyclic group, R1 and R2 are independently selected from H, a substituted or unsubstituted straight chain or branched alkyl group, a substituted or unsubstituted aryl group or a heterocyclic group, and the value range of m and n is independently selected from an integer between 0 and 9. The heterocyclic dibasic acid has the advantages of good biocompatibility, low toxicity, degradability and the like, and is used for synthesizing an environment-friendly plasticizer.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of organic chemistry, and particularly relates to a heterocyclic dibasic acid containing a non-polar hydrophobic group, and a preparation method and application thereof. BACKGROUND

[0002] A plasticizer is a substance added to improve the hardness and brittleness of a material, and is an indispensable additive in the plastic industry.

[0003] At present, plasticizers mainly include o-phenyl and phospholipid plasticizers, among which phthalate esters are the most widely used plasticizers. Plasticizers can migrate and seep out during use, thereby polluting food or groundwater and affecting human health. Studies have shown that o-phenyl plasticizers can cause human endocrine disorders and have potential carcinogenicity. Therefore, a series of regulations have been introduced at home and abroad to limit the use of o-phenyl plasticizers, and thus the research and development of low-toxicity, non-toxic bio-based plasticizers have great significance. SUMMARY

[0004] To solve all or part of the above technical problems, the present application provides the following technical solutions:

[0005] One of the purposes of the present application is to provide a heterocyclic dibasic acid containing a non-polar hydrophobic group, which has a structure shown in Formula I,

[0006]

[0007] wherein Y is a substituted or unsubstituted heterocyclic group, R1 and R2 are independently selected from H, a substituted or unsubstituted straight-chain or branched alkyl group, a substituted or unsubstituted aryl group or a heterocycle, and the value range of m and n is independently selected from an integer between 0 and 9.

[0008] In some embodiments, Y is selected from an azacycle, an oxacycle or a thiacycle.

[0009] In some preferred embodiments, Y is selected from a furan group, a tetrahydrofuran group, a pyrrole group, a pyridine group, a piperidine group, a thiophene group, a pyrimidine group, an imidazole group or a pyrazine group.

[0010] In some more preferred embodiments, Y is selected from a 2,5-furan group, a 2,5-tetrahydrofuran group, a 2,5-thiophene group, a pyrimidine group or a 2,5-pyrrole group. The 2,5-furan group and the 2,5-tetrahydrofuran group are bio-based sources and have the characteristics of low toxicity and no pollution.

[0011] In some embodiments, R1 and R2 are selected from H, a C1-C6 straight-chain or branched alkyl group, a C1-C6 thioalkyl group, a substituted aryl group or an azacycle. 10 10 In some embodiments, R1 and R2 are selected from H, a C1-C6 straight-chain or branched alkyl group, a C1-C6 thioalkyl group, a substituted aryl group or an azacycle.​

[0012] In some preferred embodiments, R1, R2 are selected from H, methyl, propyl, isopropyl, isobutyl, sec-butyl, ethylmethyl sulfide, benzyl or methylindole. The above-mentioned groups are of bio-based origin, and have the characteristics of being environmentally friendly, green and pollution-free.

[0013] In some embodiments, m = n.

[0014] The second object of the present application is to provide a preparation method of a heterocyclic dicarboxylic acid containing a non-polar hydrophobic group, which comprises: subjecting a heterocyclic compound to an amidation reaction with a compound A containing at least one amino group and one carboxyl group, the heterocyclic compound having at least two substitution chains, each of the substitution chains having at least one active group, the active group reacting with an amino group on the compound A to obtain the heterocyclic dicarboxylic acid containing a non-polar hydrophobic group.

[0015] In some embodiments, the compound A has a structure shown in Formula II:

[0016]

[0017] wherein R is selected from H, a substituted or unsubstituted straight-chain or branched alkyl group, a substituted or unsubstituted aryl group or a heterocyclic ring, and j has a value in the range of 0-9.

[0018] In some embodiments, the compound A includes at least one of 2-aminopropionic acid, 2-amino-3-methylbutyric acid, 2-amino-4-methylvaleric acid, α-amino-β-methylvaleric acid, 2-amino-4-(methylmercapto)butyric acid, 2-amino-3-phenylpropionic acid, 2-amino-3-indolylpropionic acid, 11-aminododecanoic acid and 6-aminooctanoic acid. The compound A can be in the D form, the L form or the DL mixed form.

[0019] In some embodiments, the heterocyclic compound has a structure shown in Formula III,

[0020] R4-Y-R3

[0021] III

[0022] wherein Y includes a substituted or unsubstituted heterocyclic group, and P3, R4 are acyl chloride groups.

[0023] In some preferred embodiments, Y is selected from a furan group, a tetrahydrofuran group, a pyrrole group, a pyridine group, a piperidine group, a thiophene group, a pyrimidine group, an imidazole group or a pyrazine group.

[0024] In some more preferred embodiments, Y is selected from at least one of 2,5- thienedicarboxylic dichloride, 2,6-pyridinedicarboxylic dichloride, 4,6- pyrimidinedicarboxylic dichloride, 2,5-furandicarboxylic dichloride, 2,5- tetrahydrofurandicarboxylic dichloride and 2,5-pyrroledicarboxylic dichloride.

[0025] In some embodiments, the preparation method specifically comprises: dispersing the heterocyclic compound and compound A in a solvent to form a mixed reaction solution, so as to carry out the amidation reaction.

[0026] In some embodiments, the applicable solvent includes, but is not limited to, water or a combination of one or more of organic solvents, ionic liquids and other non-aqueous solvents. For example, the organic solvent can be selected from aliphatic and aromatic hydrocarbons (toluene), monohydric alcohols (ethanol), ethers (THF), ketones (acetone), halogenated hydrocarbons (dichloromethane), nitrogen compounds and sulfur compounds (DMF, DMSO) and the like. Preferably, the solvent includes at least one of water, dichloroethane, chloroform, acetone, methanol, N,N-dimethylformamide, carbon tetrachloride, tetrahydrofuran, toluene, ethanol, dichloromethane and dimethyl sulfoxide.

[0027] In some embodiments, the molar ratio of the heterocyclic compound and compound A in the amidation reaction is 1:2-1:10. Preferably, the molar ratio of the heterocyclic compound and compound A is 1:2-1:4.

[0028] In some embodiments, the reaction temperature of the amidation reaction is 0-55°C.

[0029] In some embodiments, the reaction time of the amidation reaction is 60-600 min.

[0030] In some embodiments, the pH of the amidation reaction is 7-8.5.

[0031] In some embodiments, the amidation reaction can be carried out in the presence of an auxiliary agent or the like. For example, the auxiliary agent can include a catalyst or the like. The catalyst includes, but is not limited to, triethylamine, sodium carbonate, sodium hydroxide, pyridine.

[0032] In the present application, the entire synthesis reaction of the heterocyclic diacid can be carried out in one reaction vessel, i.e., synthesized by one-pot reaction.

[0033] In the present application, after the amidation reaction is completed, the target product, i.e., the heterocyclic diacid, can be separated from the reaction mixture by post-treatment. The post-treatment includes acidification, water washing and drying to obtain the product.

[0034] The third object of the present application is to provide the non-polar hydrophobic group-containing heterocyclic dibasic acid prepared by the preparation method of any one of the above technical solutions.

[0035] The fourth object of the present application is to provide the derivative of the non-polar hydrophobic group-containing heterocyclic dibasic acid of any one of the above technical solutions, wherein the derivative comprises at least one of a salt, an ester, an amide, and an acyl halide.

[0036] The fifth object of the present application is to provide the use of the non-polar hydrophobic group-containing heterocyclic dibasic acid of any one of the above technical solutions in the preparation of an environmentally friendly plasticizer.

[0037] The sixth object of the present application is to provide a preparation method of an environmentally friendly plasticizer, wherein the preparation method comprises uniformly mixing the non-polar hydrophobic group-containing heterocyclic dibasic acid of any one of the above technical solutions with octanol to form a mixed reactant; and reacting the mixed reactant at 130-180°C for 2-6 hours to obtain the environmentally friendly plasticizer. Further, for example, sulfuric acid is added as a catalyst in the mixed reactant to perform the reaction.

[0038] The seventh object of the present application is to provide the environmentally friendly plasticizer obtained according to the above preparation method. In some preferred embodiments, the yield of the environmentally friendly plasticizer is less than 0.15%.

[0039] Compared with the prior art, the present application has at least the following technical effects:

[0040] 1) The present application provides a series of novel heterocyclic dibasic acids, which expands the types of dibasic acids at the raw material end of the polymer industry. The heterocyclic dibasic acids have good biocompatibility, low toxicity, and biodegradability.

[0041] 2) The heterocyclic dibasic acids provided by the present application can be used to synthesize plasticizers. The plasticizers developed based on this have the characteristics of environmental protection and non-toxicity due to their biomass source.

[0042] 3) The heterocyclic dibasic acids have good biocompatibility due to the presence of amide bonds in their structure, and the presence of amide bonds provides intermolecular forces, which can reduce the migration rate of the plasticizer. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0044] Figure 1is the nuclear magnetic characterization chart of the heterocyclic dibasic acid prepared in Example 4. DETAILED DESCRIPTION

[0045] The technical solutions of the present application are described in detail below in conjunction with specific examples, so that those skilled in the art can better understand and implement the technical solutions of the present application. The specific functional details disclosed herein should not be interpreted as limiting, but only as a basis for the claims and for teaching those skilled in the art to employ the representative basis of the present application in different ways in any appropriate detailed implementation.

[0046] Example 1:

[0047] Dissolve 10 g of 2,5-thiophene dicarboxylic acid chloride in 50 g of dichloroethane, stir and dissolve to obtain a 2,5-thiophene dicarboxylic acid chloride solution; weigh 12 g of 2-aminopropionic acid and dissolve it in 50 g of water, adjust the pH to 8.0 using sodium carbonate to obtain a 2-aminopropionic acid aqueous solution;

[0048] Slowly add the 2,5-thiophene dicarboxylic acid chloride solution to the 2-aminopropionic acid aqueous solution, control the pH between 7.5-8.0 during the reaction, control the temperature at 10±5℃, continue stirring for 4 h after the addition is completed to end the reaction;

[0049] Take the upper aqueous solution, neutralize to pH=1-2 using hydrochloric acid, stir for 2 h to precipitate the product, filter, wash with water, and dry to obtain the target product, with a yield of 85%.

[0050] 1 The H NMR data is δ 12.58 (s, 2H), 8.76 (s, 2H), 8.45 (s, 2H), 4.46 (m, 2H), 1.45 (d, 6H).

[0051] The heterocyclic dibasic acid containing non-polar hydrophobic groups prepared in this example has the following structural formula:

[0052]

[0053] Example 2:

[0054] Dissolve 20 g of 2,6-pyridine dicarboxylic acid chloride in 70 g of chloroform, stir and dissolve to obtain a 2,6-pyridine dicarboxylic acid chloride solution; weigh 47 g of 2-amino-3-methylbutyric acid and dissolve it in 200 g of water, adjust the pH to 8.5 using sodium carbonate to obtain a 2-amino-3-methylbutyric acid aqueous solution;

[0055] Slowly add the 2,6-pyridine dicarboxylic acid chloride solution to the 2-amino-3-methylbutyric acid aqueous solution, control the pH between 8.0-8.5 during the reaction, control the temperature at 20±5℃, continue stirring for 6 h after the addition is completed to end the reaction;

[0056] The upper aqueous solution was neutralized with hydrochloric acid to pH = 1-2, the product was precipitated by stirring for 2 h, filtered, washed with water, and dried to obtain the target product with a yield of 86%.

[0057] Product 1 H NMR data: δ 12.46 (s, 2H), 9.36 (s, 2H), 8.80 (d, 2H), 8.56 (t, 1H), 4.26 (d, 2H), 1.90 (m, 2H), 0.98 (d, 12H).

[0058] The heterocyclic dibasic acid containing non-polar hydrophobic groups prepared in this example has the following structural formula:

[0059]

[0060] Example 3:

[0061] 15 g of 4,6-pyrimidine dicarboxylic acid chloride was dissolved in 60 g of acetone to prepare a 4,6-pyrimidine dicarboxylic acid chloride solution; 25 g of 2-amino-4-methylvaleric acid was dissolved in 100 g of N,N-dimethylformamide (DMF) and 20 g of piperidine was added to prepare a 2-amino-4-methylvaleric acid solution;

[0062] The 4,6-pyrimidine dicarboxylic acid chloride solution was slowly added to the 2-amino-4-methylvaleric acid solution, and the temperature was controlled at 30±5°C; after the addition was completed, the reaction was continued for 5 h;

[0063] After the reaction was completed, the acetone was recovered by distillation under reduced pressure, and the remaining aqueous phase was acidified, washed with water, and dried to obtain the product with a yield of 85%.

[0064] Product 1 H NMR data: δ 12.55 (s, 2H), 9.89 (s, 1H), 9.46 (s, 1H), 9.38 (s, 2H), 4.55 (t, 2H), 1.75 (t, 4H), 1.49 (m, 2H), 0.90 (d, 12H).

[0065] The heterocyclic dibasic acid containing non-polar hydrophobic groups prepared in this example has the following structural formula:

[0066]

[0067] Example 4:

[0068] 23 g of DL 2-amino-4-(methylmercapto)butyric acid was dissolved in water, and the pH was adjusted to 8.0-8.5 using sodium hydroxide to obtain a DL 2-amino-4-(methylmercapto)butyric acid aqueous solution;

[0069] 10 g 2,5-furandicarboxylic acid chloride solid was slowly added to a DL 2-amino-4- (methylmercapto) butyric acid aqueous solution, the temperature was controlled at 5±5°C, the pH was controlled between 8.0-8.5, and after the addition was completed, the reaction was continued for 10 h;

[0070] The reaction solution was neutralized to pH = 1-2, filtered, washed with water, and dried to obtain the product, with a yield of 78%.

[0071] Product 1 H NMR data was δ 12.61 (s, 2H), 8.22 (d, 2H), 7.63 (s, 2H), 4.54 (dd, 2H), 2.57 (m, 4H), 2.07 (m, 10H).

[0072] The heterocyclic dibasic acid containing nonpolar hydrophobic groups prepared in this example has the following structural formula:

[0073]

[0074] Example 5:

[0075] 10 g 2,5-furandicarboxylic acid chloride was dissolved in 50 g dichloromethane to obtain solution 1; 30 g 2-amino-3-phenylpropionic acid was dissolved in 150 g DMF to obtain solution 2;

[0076] Solution 1 was slowly added to solution 2, and the reaction was carried out at 50°C±5°C for 5 h. After the reaction was completed, the solvent was recovered by distillation, and the product was obtained by washing with water and drying, with a yield of 73%.

[0077] Product 1 H NMR data was δ 12.85 (s, 2H), 8.18 (s, 2H), 7.64 (s, 2H), 7.14 (m, 10H), 4.72 (m, 2H), 3.21 (m, 4H).

[0078] The heterocyclic dibasic acid containing nonpolar hydrophobic groups prepared in this example has the following structural formula:

[0079]

[0080] Example 6:

[0081] 2,5-tetrahydrofuran dicarboxylic acid dichloride was dissolved in carbon tetrachloride to obtain a 2,5-tetrahydrofuran dicarboxylic acid dichloride solution; 2-amino-3-indolylpropionic acid was dissolved in water, and sodium carbonate was used to adjust the pH to 8.0 to obtain a 2-amino-3-indolylpropionic acid aqueous solution; the 2,5-tetrahydrofuran dicarboxylic acid dichloride solution was slowly added to the 2-amino-3-indolylpropionic acid aqueous solution, the pH was controlled between 8.0 and 8.5 during the reaction, the temperature was controlled at 10±5°C, and after the addition was completed, the reaction was continued for 6 hours.

[0082] The upper aqueous solution was taken, neutralized with hydrochloric acid to pH=1-2, stirred for 2 hours to precipitate the product, filtered, washed with water, and dried to obtain the target product, with a yield of 78%.

[0083] Product 1 H NMR data is δ 12.85 (s, 2H), 11.67 (s, 2H), 8.18 (s, 2H), 7.51 (m, 2H), 7.28 (m, 2H), 7.06 (m, 4H), 6.22 (s, 2H), 4.69 (m, 4H), 3.21 (m, 4H), 2.21 (m, 4H).

[0084] The heterocyclic dibasic acid containing nonpolar hydrophobic groups prepared in this example has the following structural formula:

[0085]

[0086] Example 7:

[0087] 10 g of 2,5-furan dicarboxylic acid dichloride was dissolved in 50 g of carbon tetrachloride to completely dissolve it, obtaining 2,5-furan dicarboxylic acid dichloride; 31.2 g of 11-aminododecanoic acid was dissolved in 150 g of DMF to obtain 11-aminododecanoic acid;

[0088] 2,5-furan dicarboxylic acid dichloride was slowly added to 11-aminododecanoic acid, and the reaction was carried out at 20°C±5°C for 5 hours. After the reaction was completed, the solvent was recovered by distillation, and the product was obtained after water washing and drying, with a yield of 78.3%.

[0089] Product 1 H NMR data is δ 11.85 (s, 2H), 7.63 (s, 2H), 7.14 (s, 2H), 4.13 (m, 2H), 2.21 (m, 4H), 1.51 (m, 8H), 1.26 (m, 15H).

[0090] The heterocyclic dibasic acid containing nonpolar hydrophobic groups prepared in this example has the following structural formula:

[0091]

[0092] Example 8

[0093] Dissolve 2,5-pyrrole dicarboxylic acid chloride in carbon tetrachloride to obtain an acyl chloride solution; dissolve 2-amino-pentanoic acid in water, and use sodium carbonate to adjust the pH to 8.0 to obtain a 2-amino-pentanoic acid aqueous solution;

[0094] Slowly drop the acyl chloride solution into the 2-amino-pentanoic acid aqueous solution, control the pH between 8.0 and 8.5 during the reaction, control the temperature at 10±5°C, continue stirring for 6 hours after the dropping is completed to end the reaction;

[0095] Take the upper aqueous solution, neutralize with hydrochloric acid to pH=1-2, stir for 2 hours to precipitate the product, filter, wash with water, and dry to obtain the target product, with a yield of 82%.

[0096] Product 1 The H NMR data is δ 12.85 (s, 2H), 12.66 (s, 2H), 9.38 (s, 2H), 7.73 (s, 2H), 4.55 (t, 2H), 1.75 (m, 4H), 1.31 (m, 4H), 0.89 (t, 6H).

[0097] The heterocyclic dibasic acid containing non-polar hydrophobic groups prepared in this example has the following structural formula:

[0098]

[0099] Example 9

[0100] Dissolve 2,5-tetrahydrofuran dicarboxylic acid chloride in chloroform to obtain a 2,5-tetrahydrofuran dicarboxylic acid chloride solution; dissolve 6-amino-octanoic acid in water, and adjust the pH to 8.1 to obtain a 6-amino-octanoic acid solution;

[0101] Drop the 2,5-tetrahydrofuran dicarboxylic acid chloride solution into the 6-amino-octanoic acid solution, control the pH between 7.8 and 8.3, control the temperature between 15-25°C, continue stirring for 3 hours after the dropping is completed to end the reaction;

[0102] Take the upper aqueous solution, neutralize with hydrochloric acid to pH=1-2, stir for 2 hours to precipitate the product, filter, wash with water, and dry to obtain the target product, with a yield of 83%.

[0103] Product 1 The H NMR data is δ 10.86 (s, 2H), 7.67 (s, 2H), 7.12 (s, 2H), 4.13 (m, 2H), 2.17 (m, 2H), 1.71 (m, 2H), 1.48 (m, 8H), 1.25 (m, 14H), 0.93 (m, 6H).

[0104] The non-polar hydrophobic group-containing heterocyclic dibasic acid prepared in the embodiment has the following structural formula:

[0105]

[0106] Example 10:

[0107] The non-polar hydrophobic group-containing heterocyclic dibasic acid prepared in Example 5 is used as a raw material, and octanol is reacted under the catalysis of sulfuric acid at 130°C for 3h. Unreacted raw materials are removed by distillation under reduced pressure to obtain an environmentally friendly plasticizer. 55 parts of the prepared environmentally friendly plasticizer, 100 parts of PVC and 1 part of BZ-F02 stabilizer are mixed to prepare a modified PVC sample. The tensile strength of the sample is measured to be 230kg / cm 2 The extraction rate of the plasticizer in the sample is measured by the extraction test ASTM D3291 to be 0.15%.

[0108] Comparative Example 1

[0109] The plasticizer obtained in Example 8 is replaced by dioctyl phthalate, and a PVC sample is prepared by the same method as in Example 8. The tensile strength of the sample is measured to be 210kg / cm 2 The extraction rate of the plasticizer in the sample is measured by the extraction test ASTM D3291 to be 0.4%.

[0110] It is illustrated that the plasticizer of the present application can have a performance comparable to that of existing plasticizers, but the plasticizer of the present application has a smaller extraction rate. This is mainly due to the higher molecular weight of the plasticizer prepared in the present application, and the presence of amide bonds provides intermolecular hydrogen bonds, which reduces the migration rate of the plasticizer. At the same time, due to the lower migration rate, and the fact that the plasticizer described in the present application is derived from biomass, the presence of amide bonds has good biocompatibility, and has the advantages of low toxicity and environmental protection.

[0111] Aspects, embodiments, features, and examples of the present application should be considered illustrative in all aspects and are not intended to limit the present application, the scope of which is defined only by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed application.

[0112] In addition, the present inventors have also carried out tests with other raw materials, process operations and process conditions described in the present specification with reference to the foregoing embodiments, and have obtained relatively ideal results.

[0113] While the application has been described with reference to the illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the application. Further, many modifications can be made to adapt a particular situation or material to the teachings of the application without departing from its scope. Therefore, it is intended that the application not be limited to the disclosed embodiments, but will include all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated otherwise, any use of the terms first, second, etc., does not denote any ordinal, or importance, but merely distinguishes one element from another.

Claims

1. A heterocyclic dibasic acid containing a nonpolar hydrophobic group, characterized in that: The heterocyclic diacid has a structure shown in formula I, ; wherein Y is a 2,5-furanyl group, R1 and R2 are independently selected from a methyl group, a propyl group, an isobutyl group, a sec-butyl group, an ethyl methyl sulfide, a benzyl group or an indole methyl group, and m and n are 0.

2. A process for producing a heterocyclic dibasic acid containing a nonpolar hydrophobic group according to claim 1, characterized by, The method comprises: The heterocyclic compound is subjected to an amidation reaction with a compound A to obtain the heterocyclic diacid containing a non-polar hydrophobic group. The heterocyclic compound has a structure shown in formula III, ； In the structure shown in formula III, Y is a 2,5-furanyl group, and R3 and R4 are acyl chloride groups. The compound A is 2-amino-3-phenylpropionic acid or 2-amino-3-indolepropionic acid.

3. The method for producing a heterocyclic dibasic acid containing a nonpolar hydrophobic group according to claim 2, characterized by, The method specifically comprises: The heterocyclic compound and the compound A are dispersed in a solvent to form a mixed reaction solution, so as to perform the amidation reaction.

4. The method for preparing heterocyclic dicarboxylic acids containing nonpolar hydrophobic groups according to claim 3, characterized in that: The solvent comprises at least one of water, dichloroethane, chloroform, acetone, methanol, N,N-dimethylformamide, carbon tetrachloride, tetrahydrofuran, toluene, ethanol, dichloromethane and dimethyl sulfoxide.

5. The method for preparing heterocyclic dicarboxylic acids containing nonpolar hydrophobic groups according to claim 2, characterized in that: In the amidation reaction, the molar ratio of the heterocyclic compound to the compound A is 1:2 to 1:

10.

6. The method for preparing heterocyclic dicarboxylic acids containing nonpolar hydrophobic groups according to claim 5, characterized in that: The molar ratio of the heterocyclic compound to the compound A is 1:2 to 1:

4.

7. The method for preparing heterocyclic dicarboxylic acids containing nonpolar hydrophobic groups according to claim 2, characterized in that: The reaction temperature of the amidation reaction is 0 to 55℃.

8. The method for preparing heterocyclic dicarboxylic acids containing nonpolar hydrophobic groups according to claim 2, characterized in that: The reaction time of the amidation reaction is 60 to 600 min.

9. The method for preparing heterocyclic dicarboxylic acids containing nonpolar hydrophobic groups according to claim 2, characterized in that: The pH of the amidation reaction is 7 to 8.

5.

10. Use of the nonpolar hydrophobic group-containing heterocyclic dibasic acid according to claim 1 in the preparation of an environmentally friendly plasticizer; the use comprising: The heterocyclic diacid containing a non-polar hydrophobic group according to claim 1 is uniformly mixed with octanol to form a mixed reaction substance; The mixed reaction substance is reacted at 130 to 180℃ for 2 to 6 hours to obtain an environmentally-friendly plasticizer.

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