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

Abstract

The application discloses a heterocyclic dibasic acid containing basic groups and a preparation method and application thereof. The heterocyclic dibasic acid containing basic groups has a structure shown in formula I: wherein Y comprises a substituted or unsubstituted heterocyclic group, and R1 and R2 are independently selected from a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. The heterocyclic dibasic acid containing basic groups can be used as an important chemical intermediate, and especially can be used as a chain extender for preparing polyurethane and the like.

Description

TECHNICAL FIELD

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

[0002] Polyurethane is an organic polymer material, and is one of the five engineering plastics. Polyurethane products have a wide range of adjustable performance, strong adaptability, strong wear resistance, aging resistance and other advantages, and are widely used in the construction industry, shoemaking and leather industry, furniture, sports and other industries.

[0003] In the use process of polyurethane, isocyanate, polyol, chain extender, salt forming agent and other additives are usually used. The chain extender plays an important role in the synthesis of polyurethane, and the structure of the chain extender will have a certain influence on the performance of polyurethane. Since the urea group formed by amino and isocyanate has higher cohesive energy, it can endow polyurethane with good physical and mechanical properties, so the chain extender containing amino is usually used to prepare polyurethane. However, the existing low molecular weight amine chain extender reacts more violently with isocyanate, and the production is not easy to control. SUMMARY

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

[0005] One of the purposes of the present application is to provide a heterocyclic dibasic acid containing a basic group, which has the structure shown in formula I:

[0006]

[0007] Wherein, Y includes a substituted or unsubstituted heterocyclic group, R1 and R2 are independently selected from a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. The alkyl group can be a straight chain alkyl group or a branched chain alkyl group.

[0008] The above technical scheme has the beneficial effects that the structure shown in formula I contains an amide bond, which is easy to form intermolecular hydrogen bonds, and the use of the structure in the synthesis of polyurethane can improve the mechanical properties of polyurethane. In addition, due to the steric hindrance effect of the structure shown in formula I and the electron-withdrawing effect of R1 and R2 groups, the use of the structure as a chain extender for the synthesis of polyurethane can reduce the reactivity of amino and isocyanate, and by adjusting the structure of R1 and R2 groups, the activity of amino can be adjusted.

[0009] In some embodiments, Y comprises a nitrogen heterocycle, an oxygen heterocycle or a sulfur heterocycle. Preferably, Y comprises a furan group, a tetrahydrofuran group, a pyrrole group, a pyridine group, a piperidine group, a thiophene group, an imidazole group or a pyrazine group. More preferably, Y comprises a 2,5-furan group, a 2,5-tetrahydrofuran group, a 2,5-pyrrole group or a 2,5-thiophene group. The heterocycle group can improve the mechanical properties and temperature resistance of the polyurethane due to its rigid structure, and the 2,5-furan group and the 2,5-tetrahydrofuran group can be derived from biomass and have low toxicity.

[0010] In some embodiments, R1 and R2 are independently selected from a substituted or unsubstituted C1-C6 alkyl group or a substituted or unsubstituted aromatic ring. The substituted or unsubstituted C1-C6 alkyl group can be a straight chain or a branched chain alkyl group. Further, R1 and R2 are independently selected from a substituted or unsubstituted benzene ring, a C1-C6 straight chain or branched chain alkyl group, a nitrogen-substituted alkyl group or an oxygen-substituted alkyl group.

[0011] Preferably, R1 and R2 are independently selected from a benzene ring, a carbonyl ethyl group, a carbonyl propyl group, a pentyl group, a butyl formamidyl group or a sec-butyl group. When R1 and R2 have the above structures, the amino groups near them can have appropriate reactivity, and when the heterocycle-based diacid containing basic groups is used as a polyurethane chain extender, the controllability of the polyurethane synthesis process can be achieved.

[0012] The second object of the present application is to provide a preparation method of a heterocycle-based diacid containing basic groups, which comprises: subjecting a compound A containing one carboxyl group and a plurality of amino groups to an amidation reaction with a compound B containing a heterocycle group, wherein the heterocycle group has at least two substitution chains, and each of the substitution chains has at least one active group, and one of the active groups reacts with a corresponding one of the amino groups in the compound A, thereby obtaining a heterocycle-based diacid containing basic groups.

[0013] In some embodiments, the compound A has a structure shown in formula II,

[0014]

[0015] wherein R is selected from a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.

[0016] The substituted or unsubstituted alkyl group can be a straight chain alkyl group or a branched chain alkyl group. Further, the substituted or unsubstituted alkyl group is preferably a C1-C6 alkyl group.

[0017] In some preferred embodiments, the compound A comprises at least one of 3,5-diaminobenzoic acid, 2-amino-3-carbomoylpropionic acid, 2-amino-4-carboxamidobutyric acid, 2-amino-5-guanidinylvaleric acid and 2,6-diaminohexanoic acid. The compound A can be D-form, L-form or a mixture of D-form and L-form. The compound A can be bio-based, low toxicity and biodegradable.

[0018] In some embodiments, the compound B has a structure of Formula III,

[0019] R4-Y-R3

[0020] III

[0021] wherein Y comprises a substituted or unsubstituted heterocyclic group, and R3 and R4 are independently selected from an ester group or an acyl chloride group.

[0022] Further preferably, Y comprises a furan group, a tetrahydrofuran group, a pyrrole group, a pyridine group, a piperidine group, a thiophene group, an imidazole group or a pyrazine group.

[0023] In some more preferred embodiments, the compound B comprises at least one of 2,5-furandicarboxylic acid dichloride, 2,5-thiophenedicarboxylic acid dichloride, 2,5-tetrahydrofuran dicarboxylic acid dichloride, 2,5-tetrahydrofuran dicarboxylic acid dimethyl ester, 2,5-pyrroledicarboxylic acid dichloride and 2,6-pyridinedicarboxylic acid dichloride.

[0024] In some embodiments, the preparation method comprises uniformly dispersing the compound A and the compound B in a solvent to form a mixed reaction solution for the amidation reaction. The solvent can be water or a non-aqueous solvent, and the non-aqueous solvent comprises an organic solvent or an ionic liquid. Specifically, the solvent can comprise at least one of a mono-alcohol, an ether, a ketone, a halogenated hydrocarbon, a nitrogen compound and a sulfur compound.

[0025] Further, the preparation method specifically comprises uniformly dispersing the compound A of Formula II and the compound B of Formula III in a solvent to form a mixed reaction solution for the amidation reaction.

[0026] In some embodiments, the preparation method specifically comprises uniformly dispersing the compound A in a first solvent to obtain a solution A, uniformly dispersing the compound B in a second solvent to obtain a solution B, and mixing the solution A and the solution B to obtain the mixed reaction solution.

[0027] In some embodiments, the first solvent and the second solvent are independently selected from at least one of water, ethanol, tetrahydrofuran, acetone, dichloromethane, dichloroethane, chloroform, N,N-dimethylformamide and dimethyl sulfoxide.

[0028] In some embodiments, the preparation method can perform the amidation reaction in the presence of an auxiliary agent. For example, the preparation method specifically includes: performing the amidation reaction of compound A and compound B in the presence of a catalyst. Preferably, the catalyst includes, but is not limited to, one or more of triethylamine, pyridine, sodium ethoxide, and sodium carbonate.

[0029] In some embodiments, the molar ratio of compound B to compound A in the amidation reaction is 1:2-1:10. Preferably, it is 1:2-1:4.

[0030] In some embodiments, the reaction temperature of the amidation reaction is 0-50℃.

[0031] In some embodiments, the reaction time of the amidation reaction is 60-600 min.

[0032] In some embodiments, the pH condition of the amidation reaction is 7-9.

[0033] The entire synthesis reaction of the basic group-containing heterocyclic dibasic acid can be performed in one reaction vessel, that is, synthesized by one-pot reaction.

[0034] After the amidation reaction is completed, the target product, that is, the basic group-containing heterocyclic dibasic acid, can be separated from the reaction mixture by post-treatment. The post-treatment includes acidification, salification, and recrystallization to obtain the product.

[0035] The third object of the present application is to provide a basic group-containing heterocyclic dibasic acid prepared by the preparation method described in the above technical solution.

[0036] The fourth object of the present application is to provide a derivative of the basic group-containing heterocyclic dibasic acid described in any one of the above technical solutions, wherein the derivative includes at least one of a salt, an ester, and an amide.

[0037] The fifth object of the present application is to provide the use of the basic group-containing heterocyclic dibasic acid described in the above technical solution in the preparation of a chain extender for polyurethane or as a chain extender for polyurethane.

[0038] The sixth object of the present application is to provide a synthesis method for preparing polyurethane, which includes: reacting a mixed reaction system containing isocyanate, polyol, solvent, and chain extender to prepare polyurethane; and the chain extender includes the basic group-containing heterocyclic dibasic acid described in any one of the above technical solutions. The reaction temperature is, for example, 60-120℃.

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

[0040] (1) The application provides a novel heterocyclic dibasic acid containing basic groups, which can be used as an important chemical intermediate, for example, as a chain extender for preparing water-based polyurethane.

[0041] (2) The heterocyclic dibasic acid containing basic groups provided by the application can significantly strengthen the strength of polyurethane as a chain extender for polyurethane due to the intermolecular hydrogen bonding and the rigidity of the heterocyclic group.

[0042] (3) The heterocyclic dibasic acid containing basic groups provided by the application can be used as a chain extender for synthesizing polyurethane by adjusting the R1 and / or R2 groups and then adjusting the reactivity of the amino group, so that the reaction rate of the chain extender with isocyanate can be adjusted, and the reaction in the polyurethane preparation process can be controlled. BRIEF DESCRIPTION OF DRAWINGS

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

[0044] Figure 1 It is the nuclear magnetic characterization diagram of the heterocyclic dibasic acid containing basic groups prepared in Example 1 of the application. DETAILED DESCRIPTION

[0045] The technical solutions of the application will be described in detail below with specific examples, so that those skilled in the art can better understand and implement the technical solutions of the 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 application in different ways in any appropriate detailed embodiment.

[0046] Example 1:

[0047] 10g of 3,5-diaminobenzoic acid was weighed and dissolved in water, and the pH was adjusted to 8.0±0.5 to obtain a 3,5-diaminobenzoic acid solution; 4.2g of 2,5-furandicarboxylic acid chloride was dissolved in dichloroethane to obtain a 2,5-furandicarboxylic acid chloride solution;

[0048] Under ice bath conditions, the 2,5-furandicarboxylic acid chloride solution was slowly added to the 3,5-diaminobenzoic acid solution, and the pH was controlled at 8.0±0.5. After 4h of reaction, the pH was adjusted to about 2.0-3.0 using hydrochloric acid, and the water was evaporated and recrystallized with ethanol to obtain the product, with a yield of 46%.

[0049] Figure 1 is the nuclear magnetic characterization chart of the product prepared in this example, 1 H NMR data is δ 12.74 (s, 2H), 10.21 (s, 2H), 7.83 (t, 2H), 7.64 (s, 2H), 7.33 (t, 2H), 7.27 (t, 2H), 5.21 (s, 4H).

[0050] The product structure is as follows:

[0051]

[0052] Example 2:

[0053] Take 15g 2-amino-3-aminoformyl propanoic acid and dissolve it in water, adjust the pH to 8.5±0.5 to obtain a 2-amino-3-aminoformyl propanoic acid solution; take 5.5g 2,5-thiophene dicarboxylic acid chloride and dissolve it in chloroform to obtain a 2,5-thiophene dicarboxylic acid chloride solution;

[0054] Slowly add the 2,5-thiophene dicarboxylic acid chloride solution to the 2-amino-3-aminoformyl propanoic acid solution at 10°C, control the pH at 8.5±0.5, after 2h of reaction, adjust the pH to 4.0±0.5 using hydrochloric acid, evaporate the water, and recrystallize using isopropyl alcohol to obtain the product, with a yield of 58%.

[0055] 1 H NMR data is δ 12.57 (s, 2H), 8.78 (s, 2H), 8.45 (s, 2H), 7.03 (s, 4H), 4.74 (t, 2H), 2.79 (m, 4H).

[0056] The product structure is as follows:

[0057]

[0058] Example 3:

[0059] Take 10g 2,6-diaminohexanoic acid and dissolve it in water, adjust the pH to between 7.0 and 7.5 to obtain a 2,6-diaminohexanoic acid solution; take 5.2g 2,5-tetrahydrofuran dimethyl ester and dissolve it in chloroform to obtain a 2,5-tetrahydrofuran dimethyl ester solution;

[0060] Slowly add the 2,5-tetrahydrofuran dimethyl ester solution to the 2,6-diaminohexanoic acid solution at room temperature, control the pH at between 7.0 and 7.5, and after 3h of reaction, the reaction is complete. Adjust the pH to between 4 and 4.5, and pass through a silica gel column to obtain the product, with a yield of 38%;

[0061] 1H NMR data is δ 12.66 (s, 2H), 8.30 (s, 2H), 4.69 (t, 2H), 4.55 (t, 2H), 2.69 (t, 4H), 2.21 (m, 4H), 1.76 (m, 4H), 1.5 (m, 8H), 1.25 (m, 4H).

[0062] The product structure is as follows:

[0063]

[0064] Example 4:

[0065] Take 20 g of 2-amino-5-guanidylvaleric acid and dissolve it in water, and use hydrochloric acid to adjust the pH to 7.5±0.2 to obtain a 2-amino-5-guanidylvaleric acid solution; take 5.5 g of 2,5-pyrrole dicarboxylic acid dimethyl ester and dissolve it in dimethyl sulfoxide to obtain a 2,5-pyrrole dicarboxylic acid dimethyl ester solution;

[0066] Slowly add the 2,5-pyrrole dicarboxylic acid dimethyl ester solution to the 2-amino-5-guanidylvaleric acid solution at 50°C, control the pH at about 7.5, and end the reaction after 2 h of reaction. Adjust the pH of the reaction liquid to about 5.0-5.5, and purify it on a silica gel column to obtain the product, with a yield of 32%;

[0067] 1 H NMR data is δ 12.86 (s, 1H), 12.66 (s, 2H), 9.38 (s, 2H), 7.84 (s, 2H), 7.71 (s, 2H), 6.61 (s, 4H), 4.55 (t, 2H), 3.43 (t, 4H), 2.46 (s, 2H), 1.76 (m, 4H), 1.51 (m, 4H).

[0068] The product structure is as follows

[0069]

[0070] Example 5:

[0071] Take 20 g of 2-amino-5-guanidylvaleric acid and dissolve it in water, and use hydrochloric acid to adjust the pH to 7.5±0.2 to obtain a 2-amino-5-guanidylvaleric acid solution; take 5.5 g of 2,5-pyrrole dicarboxylic acid dimethyl ester and dissolve it in dimethyl sulfoxide to obtain a 2,5-pyrrole dicarboxylic acid dimethyl ester solution;

[0072] Slowly add the 2,6-pyridine dicarboxylic acid chloride solution to the 2-amino-4-carboxamide butyric acid solution at 10°C, control the pH at 8.5±0.5, and after 2 h of reaction, use hydrochloric acid to adjust the pH to 4.0±0.5, evaporate the water, and recrystallize the product from isopropyl alcohol to obtain the product, with a yield of 46%.

[0073] 1 HNMR data is δ 12.66 (s, 2H), 9.38 (s, 2H), 8.80 (d, 2H), 8.56 (t, 1H), 7.03 (s, 4H), 4.55 (t, 2H), 2.05 (d, 8H).

[0074] The product structure is as follows:

[0075]

[0076] Example 6:

[0077] 50 g of polytetrahydrofuran (number average molecular weight of 500), 28.8 g of isophorone diisocyanate were weighed into 80 ml of acetone, heated to 70°C and reacted for 3 h;

[0078] Then 8.3 g of the basic group-containing heterocyclic dibasic acid prepared in Example 1 was added as a chain extender, and reacted at 60°C for 2 h, and then cooled to 50°C, 1.5 g of triethylamine was added for neutralization, 200 g of water was added and stirred for 30 min, and then distilled under reduced pressure to remove acetone to obtain an aqueous polyurethane.

[0079] A sample was prepared, dried, and tested by a universal testing machine to have a tensile strength of 28 MPa, and the aqueous polyurethane was successfully prepared, indicating that the product in Example 1 can be used as a polyurethane chain extender.

[0080] Comparative Example 1:

[0081] Comparative Example 1 and Example 6 differ only in that the chain extender is replaced by ethylenediamine ethanesulfonic acid sodium, and the prepared polyurethane is prepared according to the same steps as Example 6. A comparative sample was prepared by the same steps as Example 6, and its tensile strength was detected to be 20.3 MPa.

[0082] It can be seen that when the basic group-containing heterocyclic dibasic acid in the present application is used as a chain extender, the tensile strength of the prepared polyurethane is relatively high, because the basic group-containing heterocyclic dibasic acid described in the present application greatly improves the mechanical properties of the polyurethane due to the existence of hydrogen bonds and heterocyclic groups.

[0083] In addition, the heat release in the chain extension process of Comparative Example 1 is relatively obvious, indicating that the reaction rate is relatively fast, and the temperature is relatively difficult to control during the amplification process, while the heat release in the chain extension process of Example 6 is relatively stable, and the temperature can be removed in time, and the reaction process is easy to control. Because the branched structure substituted on the heterocyclic group has a mild reactivity, especially when it has the R1, R2 groups described in the present application, the steric hindrance effect and electron-withdrawing effect of the branched structure can make the amino group have a mild reactivity, thereby realizing the controllability of the reaction in the polyurethane synthesis process.

[0084] Aspects, embodiments, features, and examples of the present application should be considered in all respects as illustrative only and not restrictive in any manner. The scope of the application is only limited by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art, and the application incorporates by reference any prior art reference mentioned herein.

[0085] In addition, the inventors of the present application have also tested the aforementioned embodiments with other raw materials, process operations, process conditions described in the present specification, and all have obtained relatively ideal results.

[0086] While the present application has been described with reference to illustrative embodiments, those skilled in the art will appreciate that various other changes, omissions, and / or additions can be made thereto and still fall within 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, the application is not intended to be limited to the disclosed embodiments associated with performing the application and it is intended that the application encompass all embodiments falling within the scope of the appended claims. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another.

Claims

1. A heterocyclic dibasic acid containing a basic group, characterized in that, The basic group-containing heterocyclic dibasic acid has a structure shown in Formula I: ， wherein Y is selected from a 2,5-furanyl group, a 2,5-tetrahydrofuranyl group, a 2,5-pyrrolyl group or a 2,5-thiophenyl group, and R1, R2 are independently selected from any one of a benzene ring, a carbonyl ethyl group, a carbonyl propyl group, a pentyl group, a butyl methyl amidine group or a sec-butyl group.

2. The process for producing the basic group-containing heterocyclic dibasic acid according to Claim 1, characterized by, The method comprises: carrying out an amidation reaction of a compound A and a compound B, the compound A containing one carboxyl group and multiple amino groups, the compound B comprising a heterocyclic group, and the heterocyclic group having at least two substitution chains, each of the substitution chains having at least one active group, one of the active groups reacting with a corresponding one of the amino groups in the compound A to obtain a basic group-containing heterocyclic dibasic acid; wherein the compound A is selected from at least one of 3,5-diaminobenzoic acid, 2-amino-3-carbamoylpropionic acid, 2-amino-4-carboxamidobutyric acid, 2-amino-5-guanidinopentanoic acid and 2,6-diaminohexanoic acid; and the compound B is selected from at least one of 2,5-furandicarboxylic acid dichloride, 2,5-thiophenedicarboxylic acid dichloride, 2,5-tetrahydrofurandicarboxylic acid dichloride, 2,5-tetrahydrofurandicarboxylic acid dimethyl ester, 2,5-pyrrolinedicarboxylic acid dimethyl ester and 2,6-pyridinedicarboxylic acid dichloride.

3. The method for preparing heterocyclic dicarboxylic acids containing basic groups according to claim 2, characterized in that, The method comprises: uniformly dispersing the compound A and the compound B in a solvent to form a mixed reaction solution for the amidation reaction.

4. The process for preparing a basic group-containing heterocyclic dibasic acid according to claim 3, characterized by: The solvent comprises at least one of water, ethanol, tetrahydrofuran, acetone, dichloromethane, dichloroethane, chloroform, N,N-dimethylformamide and dimethyl sulfoxide.

5. The method for preparing a heterocyclic dicarboxylic acid containing a basic group according to claim 2, characterized in that: In the amidation reaction, the molar ratio of the compound B to the compound A is 1:2 to 1:

10.

6. The process for preparing a basic group-containing heterocyclic dibasic acid according to claim 5, characterized by: The molar ratio of the compound B to the compound A is 1:2 to 1:

4.

7. The process for preparing a basic group-containing heterocyclic dibasic acid according to claim 2, characterized by: The reaction temperature of the amidation reaction is 0 to 50°C.

8. The process for preparing a basic group-containing heterocyclic dibasic acid according to claim 2, characterized by: The reaction time of the amidation reaction is 60 to 600 min.

9. The process for preparing a basic group-containing heterocyclic dibasic acid according to claim 2, characterized by: The pH condition of the amidation reaction is 7 to 9.

10. Use of the basic group-containing heterocyclic dibasic acid in claim 1 in the preparation of a chain extender for polyurethane or as a chain extender for polyurethane.

11. A method of synthesizing a polyurethane, characterized by, The method comprises: reacting a mixed reaction system comprising isocyanate, polyol, solvent and chain extender to obtain polyurethane; the chain extender comprising the basic group-containing heterocyclic dibasic acid in claim 1.

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