Preparation method and application of 2, 2, 4, 4-polysubstituted-1, 3-cyclobutanediol

Abstract

The invention provides a preparation method of 2, 2, 4, 4-polysubstituted-1, 3-cyclobutanediol with an adjustable cis-trans ratio, 2, 2, 4, 4-polysubstituted-1, 3-cyclobutanedione is used as a raw material, a reduction reaction is carried out in the presence of at least one transition metal catalyst and alkanol, and the cis-trans ratio in the product is controlled by controlling the addition amount of the alkanol. According to the production method of the 2, 2, 4, 4-polysubstituted-1, 3-cyclobutanediol, the cis-trans ratio of the product can be effectively controlled, artificial regulation and control of the cis-trans ratio can be realized, the cis-trans ratio can be up to 9 or above, and the method has remarkable application advantages and industrial application value.

Description

Technical Field

[0001] The invention belongs to the field of organic synthesis, and specifically relates to a preparation method and application of 2,2,4,4-polysubstituted-1,3-cyclobutanediol with adjustable cis-trans ratio. Background Art

[0002] 2,2,4,4-polysubstituted-1,3-cyclobutanediol (CBDO) is an alicyclic diol and a precursor for the production of various polymers including polyester, modified polyester, modified polycarbonate, etc. The glass transition temperature of traditional polyester is relatively low, and its application in medium and high temperature fields is subject to certain restrictions. The addition of CBDO can significantly improve the glass transition temperature, weather resistance and transparency of polyester. Polyester synthesized using CBDO has excellent physical properties similar to bisphenol A, such as high impact strength, excellent dimensional stability, and high glass transition temperature. Polyester synthesized using CBDO does not contain carcinogens and other toxic substances; polyester synthesized using CBDO also has properties that PC synthesized using bisphenol A does not have, such as good chemical resistance, hydrolysis stability, and high ductility.

[0003] However, since CBDO contains a four-membered carbon ring in the middle, the two hydroxyl groups in the para position are in different positions, resulting in the existence of cis-trans isomers in CBDO. The glass transition temperature of the obtained polyester will also be different due to the different cis-trans ratios of CBDO, which will affect the final use scenario. In order to achieve better performance of polyester, people prefer to obtain CBDO with a high cis-trans ratio, or even CBDO with an artificially controllable cis-trans ratio, to synthesize polyesters with different properties to meet a wider range of use scenarios.

[0004] Therefore, it is urgent to find a method to achieve the production of 2,2,4,4-polysubstituted-1,3-cyclobutanediol with adjustable cis-trans ratio, especially to synthesize 2,2,4,4-polysubstituted-1,3-cyclobutanediol with high cis-trans ratio, so as to facilitate the synthesis of high-performance polyesters and polycarbonates. Summary of the invention

[0005] In order to overcome the above-mentioned defects existing in the prior art, the present invention provides a method for preparing 2,2,4,4-polysubstituted-1,3-cyclobutanediol with an adjustable cis-trans ratio, which can effectively control the cis-trans ratio of the product, is conducive to the synthesis of high cis-trans ratio 2,2,4,4-polysubstituted-1,3-cyclobutanediol, and is convenient for preparing polyesters or polycarbonates with required properties.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] The present invention provides a method for preparing 2,2,4,4-polysubstituted-1,3-cyclobutanediol with adjustable cis-trans ratio, as shown in formula (I):

[0008]

[0009] Wherein, R1 and R2 are independently hydrogen, linear or branched C1-C9 alkyl, or together form a divalent bridging group containing carbon atoms. Preferably, R1 and R2 are independently hydrogen, methyl, ethyl, or together form a cyclobutylene group, a cyclopentylene group, or a cyclohexylene group.

[0010] The method of the present invention comprises the following steps:

[0011] S1: using the compound 2,2,4,4-polysubstituted-1,3-cyclobutanedione of formula (II) as a raw material, and subjecting it to a reduction reaction in the presence of at least one transition metal catalyst,

[0012]

[0013] wherein R1 and R2 have the same meanings as in formula (I),

[0014] wherein the reduction reaction is carried out in the presence of at least one alkanol of formula (III),

[0015] HO-Z-OH(III)

[0016] wherein Z is a hydrocarbon chain having 3 to 6 main chain carbon atoms, the hydrocarbon chain is unsubstituted or substituted and may be part of a carbocyclic ring, a heterocyclic ring or an aromatic ring or a heteroaromatic ring, preferably, the total number of carbon atoms of the alkanol of formula (III) does not exceed 12;

[0017] S2: Separate the reaction mixture obtained in step S1 to obtain the compound of formula (I).

[0018] Furthermore, the cis-trans ratio c / t of the compound of formula (I) (i.e., the molar ratio of formula (IV) to formula (V) in the compound) and the molar ratio n of the added alkanol of formula (III) to formula (II) satisfy the following relationship:

[0019] 0.5411+0.2338*n≤c / t≤0.5414*e 0.5922*n

[0020] in,

[0021]

[0022] In the present invention, the amount of the alkanol of formula (III) added can be determined according to the target cis-trans ratio c / t. In some embodiments, n is 1 to 10 and c / t is between 0.8 and 10.

[0023] In step S1 of the method of the present invention, at least one compound of formula (II) is subjected to a hydrogenation reaction with hydrogen in the presence of at least one alkanol of formula (III) and at least one transition metal catalyst;

[0024] The compound of formula (II) is a 1,3-diunsaturated hydrocarbon, which is unsubstituted or substituted by a linear or branched C1-C4 alkyl group at the 2- and 4-positions. Preferably, the compound of formula (II) is selected from 1,3-cyclobutanedione, 2,2,4,4-tetramethyl-1,3-cyclobutanedione and 2,2,4,4-dicyclopentylidene-1,3-cyclobutanedione. Most preferred is 2,2,4,4-tetramethyl-1,3-cyclobutanedione;

[0025] The alkanol of formula (III) is an at least dihydroxy alkanol in which two hydroxyl groups are attached to a hydrocarbon chain having 3 to 6 carbon atoms, which is unsubstituted or substituted (the substituents may be methyl, ethyl, hydroxyl, hydroxymethyl, mercapto, etc.) and may be part of a carbocyclic, heterocyclic or aromatic or heteroaromatic ring. Suitable alkanols of formula (III) are selected from 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,2,3-propanetriol (glycerol), diglycerol (a mixture of glycerol dimers coupled at the primary and secondary hydroxyl groups), 3-mercaptopropane-1,2-diol (thioglycerol), dithiothreitol, 1,1,1-trimethylolpropane, 1,2-butanediol, 1,3-butanediol, 2,4-butanediol, 2,4-dimethyl-1,3-butanediol , pentaerythritol, cyclohexane-1,2-diol, 1,4-dioxane-2,3-diol, 1,2,3-butanetriol, 1,3,4-butanetriol, 1,2,3-heptanetriol, 4-menthane-1,7,8-triol, 3-butene-1,2-diol, benzene-1,2-diol (catechol), 3-chlorocatechol, indan-1,2-diol, tartaric acid, pentose and hexose (including mannitol, sorbitol, xylitol, threitol, erythritol, maltitol and lactitol, etc.). Particularly preferred alkanols of formula (III) are 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 2,4-butanediol, pentaerythritol, pentose and hexose. Most preferred are 1,3-propanediol, pentaerythritol, pentoses and hexoses.

[0026] As a preferred embodiment, step S1 is carried out in the presence of at least one acid;

[0027] Furthermore, the acid in step S1 is selected from at least one of Bronsted acid, Lewis acid and acidic ion exchanger. Preferably, the amount of the acid added is 1-10%, preferably 3-8%, based on the molar number of hydrogen ions of the acid, of the molar number of the compound of formula (II);

[0028] As a specific embodiment, Bronsted acid is preferred, and preferred examples are trifluoroacetic acid, formic acid, hydrochloric acid, sulfuric acid, nitric acid, acidic pyridinium salts and p-toluenesulfonic acid;

[0029] As a specific embodiment, an acidic ion exchanger is preferred, in particular a sulfonated polystyrene. In a preferred embodiment, the acid is an acidic material that is insoluble in the reaction mixture, preferably an acidic support material of a heterogeneous hydrogenation catalyst;

[0030] Furthermore, the acidic ion exchanger is a macroporous strongly acidic polystyrene resin with a specific surface area of ​​40 to 70 m 2 / g, pore volume 0.2~0.5mL / g, H + The exchange capacity is ≥1 mmol / g, preferably a macroporous sulfonic acid polystyrene resin, more preferably at least one of A15, A35, A45, A70, D005, D009, and DNW-II resins.

[0031] In step S1 of the method of the present invention, the transition metal catalyst, the transition metal is selected from Ru, Co, Ir, Rh, Ni, Pd and Pt, preferably, the transition metal is Ru;

[0032] Furthermore, the transition metal catalyst may be a transition metal, a transition metal compound or a transition metal complex: the transition metal is in the form of a metal element, or an alloy formed by a metal element and a carrier (the content of the metal element in the alloy may be 0.2 to 10%), or a metal element obtained by in-situ reduction or pre-reduction of a metal oxide; the transition metal compound contains a catalytic metal in the form of a metal salt, such as a carboxylate; the transition metal complex contains a transition metal in a coordinated state, such as a complex formed by acetylacetone, a phosphine-containing ligand, a nitrogen-containing ligand and a transition metal, or a complex generated by an in-situ reaction of a transition metal compound and a ligand under the reaction conditions of step S1;

[0033] Furthermore, the transition metal catalyst is a ruthenium-carbon catalyst;

[0034] As a preferred embodiment, the amount of transition metal catalyst added is 0.5 to 40%, preferably 15 to 30%, based on the molar number of transition metal.

[0035] Furthermore, the reducing agent of the reduction reaction in step S1 is hydrogen, the reaction temperature is 30 to 250° C., and the reaction pressure is 0 to 30 MPaG;

[0036] Furthermore, the temperature during the reduction reaction in step S1 is generally in the range of 30°C to 250°C, more preferably in the range of 50°C to 150°C, further preferably 100°C to 150°C;

[0037] Furthermore, the reduction reaction in step S1 is usually carried out at a partial pressure of hydrogen at various reaction temperatures. Preferably, the hydrogen pressure is 0 to 30 MPaG, more preferably 5 to 20 MPaG, and further preferably 10 to 15 MPaG. The hydrogen pressure can be adjusted according to the activity of the hydrogenation catalyst used.

[0038] The reduction reaction in step S1 can be carried out in an inert solvent under the reaction conditions. Suitable solvents are preferably esters of aliphatic carboxylic acids and aliphatic alcohols, such as isobutyl isobutyrate or ethyl acetate, aromatic compounds, such as toluene and xylene, mixtures of hydrocarbons and hydrocarbons, ethers, such as tert-butyl methyl ether or tetrahydrofuran. Monobasic alkanols such as methanol, ethanol, n-propanol, isopropanol, n-butanol and isobutanol or ketones such as acetone or methyl ethyl ketone are also preferably used as solvents. In principle, ionic liquids can also be used as solvents. Preferred ionic liquids are N, N'-dialkyl imidazole salts, such as N-butyl-N'-methyl imidazole salts, tetraalkyl ammonium salts, such as tetra-n-butyl ammonium salts, N-alkyl pyridinium salts, such as N-butyl pyridinium salts, tetraalkyl salts, such as trihexyl (tetradecyl) salts, particularly tetrafluoroborate, acetate, tetrachloroaluminate, hexafluorophosphate, chloride and toluenesulfonate of these salts.

[0039] As a preferred embodiment, the reduction reaction of step S1 is carried out in the presence of water. Preferably, the reaction is carried out in the presence of 100 to 1000 times (e.g., 150 times, 200 times, 300 times, 400 times, 500 times, etc.) the molar number of transition metal.

[0040] The reduction reaction in step S1 can be carried out continuously, semi-continuously or discontinuously;

[0041] The reduction reaction in step S1 can be carried out in principle in all reactors known to those skilled in the art for such reactions. A suitable reactor is usually selected according to the selected transition metal catalyst;

[0042] Furthermore, the reactor of step S1 may be a stirred tank, a bubbling bed, a slurry bed, a fixed bed or a trickle bed; the reaction may be performed in an intermittent or continuous process, preferably a continuous process;

[0043] Furthermore, when a homogeneous catalyst is used in step S1, the reactor is preferably a stirred tank or a bubbling bed; when a heterogeneous catalyst is used, the reactor is preferably a slurry bed, a fixed bed or a trickle bed.

[0044] In the process of the present invention, in step S2, the compound of formula (I) is at least partially separated from a reaction mixture comprising the compound of formula (I), unconverted compound of formula (II), unconverted alkanol of formula (III), optional solvent and optional water. The separation of the compound of formula (I) can in principle be carried out by all separation methods known to those skilled in the art. Preferably, the compound of formula (I) is separated by distillation, crystallization, extraction, adsorption or a combination of these methods;

[0045] Furthermore, it is particularly preferred to separate the compound of formula (I) by distillation or crystallization. The distillation can be carried out by methods known in principle to the person skilled in the art. Preferably, the distillation is carried out in an evaporator or a distillation unit comprising an evaporator and one or more distillation columns with trays or packings. Preferably, the crystallization is carried out in a crystallizer;

[0046] Furthermore, the separation method in step S2 is distillation, crystallization or a combination of the two.

[0047] The present invention also provides a method for producing polyester or polycarbonate, wherein the diol used in the polyester or polycarbonate includes the alcohol of formula (I) synthesized by the above method.

[0048] The present invention also provides a method for producing polyester, wherein the diol used in the polyester comprises the alcohol of formula (I) synthesized through the above steps, which undergoes esterification reaction with an acid alone or together with other alcohols to synthesize the polyester.

[0049] The present invention also provides a method for producing polycarbonate, wherein the diol used in the polyester includes the alcohol of formula (I) synthesized through the above steps, which undergoes esterification or transesterification reaction with phosgene or carbonate alone or together with other alcohols to synthesize the polycarbonate.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The method for producing 2,2,4,4-polysubstituted-1,3-cyclobutanediol of the present invention has a high cis-trans ratio of the product, which can reach about 10;

[0052] In addition, the cis-trans ratio can be adjusted within a certain range, especially 2,2,4,4-polysubstituted-1,3-cyclobutanediol with a high cis-trans ratio can be synthesized, which makes it easy to adjust the performance of the synthesized high-performance polyesters and polycarbonates according to performance requirements and meet the needs of various downstream application scenarios. DETAILED DESCRIPTION

[0053] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments.

[0054] The sources of the reagent raw materials used in the examples and comparative examples of the present invention are as follows:

[0055] Ruthenium-carbon catalyst (ruthenium content 5%), tetramethyl-1,3-cyclobutanedione, etc. were purchased from Merck Reagent Co., Ltd.;

[0056] Isobutyl isobutyrate was purchased from Eastman Company;

[0057] 1,3-Propanediol was purchased from Aladdin Reagent Co., Ltd.;

[0058] Hydrogen was purchased from Air Liquide, Inc.;

[0059] Unless otherwise specified, other reagents and raw materials are commercially available.

[0060] The elemental analysis was performed using Euro Vector's EA3000 elemental analyzer with a carrier gas of 80 kPa, 100 mL / min, 15 mL of oxygen, an oxidation time of 10 s, and an oven temperature of 130 °C.

[0061] NMR spectroscopy was performed using a Bruker AVANCE III NMR spectrometer.

[0062] The raw material conversion rate and product selectivity were calibrated by gas chromatography internal standard method, wherein conversion rate = (number of moles of reaction raw materials - number of moles remaining after the reaction) / number of moles of reaction raw materials × 100%, product selectivity = number of moles of product after the reaction / (number of moles of reaction raw materials - number of moles of raw materials remaining after the reaction) × 100%.

[0063] The gas chromatograph was Agilent Technologies GC-7820, the gas chromatographic column was a 0.25 mm × 30 m DB-5 capillary column, the column box temperature was programmed from 40 °C to 280 °C at a rate of 15 °C / min and maintained for 5 min, an FID detector was used, the vaporization chamber temperature was 280 °C, the detector temperature was 300 °C, the argon carrier flow rate was 2.1 mL / min, the hydrogen flow rate was 30 mL / min, the air flow rate was 400 mL / min, and the injection volume was 1.0 μL.

[0064] Unless otherwise specified, the reaction conversion rates and selectivity percentages used in the examples and comparative examples of the present invention are all molar percentages, and the purity contents of substances are all mass percentages.

[0065] General Procedure

[0066] In a glove box, 1 mmol of the compound of formula (II), a certain amount of the compound of formula (III) and 0.05 mmol of trifluoroacetic acid (added in the form of a 0.14 M toluene solution), 0.437 g of a ruthenium-carbon catalyst, and 0.5 g of water were transferred to a steel autoclave with a volume of 100 mL and an internal stirrer under an inert gas atmosphere, and isobutyl isobutyrate was added to 60 mL. The autoclave was purged 3 times with hydrogen. The autoclave was filled with hydrogen to a pressure of 0.5 MPaG. Stirring was turned on and the autoclave was heated to the reaction temperature with the aid of an oil bath. The autoclave was continuously filled with hydrogen to maintain the reaction pressure, and the reaction temperature was maintained by an oil bath and cooling water in the autoclave to reach the reaction temperature and pressure. The reaction was started for 8 hours.

[0067] Examples 1-15

[0068] The reaction was carried out according to the general procedure described above, and the required process conditions and experimental results are shown in Table 1.

[0069] Table 1

[0070]

[0071]

[0072] Examples 16-17

[0073] The experimental process is the same as that of Examples 1-15, except that no acid is added in Example 16 and no water is added in Example 17. The required process conditions and experimental results are shown in Table 2.

[0074] Table 2

[0075]

[0076]

[0077] Comparative Example 1-2

[0078] The experimental process is the same as that of Examples 1-15. In Comparative Examples 1-2, the compound of formula (III) is replaced by a monohydric alcohol. The required process conditions and experimental results are shown in Table 3.

[0079] Table 3

[0080]

[0081] It can be seen from the above examples and comparative examples that the production method of 2,2,4,4-polysubstituted-1,3-cyclobutanediol described in the present invention can effectively control the cis-trans ratio of the product and realize artificial regulation of the cis-trans ratio, and the cis-trans ratio can be as high as 9.78, which has significant application advantages and has industrial application value.

[0082] Unless otherwise defined, the terms used in the present invention have the meanings commonly understood by those skilled in the art.

[0083] The embodiments described in the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Those skilled in the art may make various other substitutions, changes and improvements within the scope of the present invention. Therefore, the present invention is not limited to the above embodiments, but is only limited by the claims.

Claims

1. A method for preparing 2,2,4,4-polysubstituted-1,3-cyclobutanediol represented by formula (I), in, R1 and R2 are independently hydrogen, linear or branched C1-C9 alkyl, or together form a divalent bridging group containing carbon atoms. Preferably, R1 and R2 are independently hydrogen, methyl, ethyl, or together form a cyclobutylene, cyclopentylene, or cyclohexylene. The method comprises the following steps: S1: using the compound 2,2,4,4-polysubstituted-1,3-cyclobutanedione of formula (II) as a raw material, and subjecting it to a reduction reaction in the presence of at least one transition metal catalyst and an alkanol of formula (III), wherein R1 and R2 have the same meanings as in formula (I), HO-Z-OH(III) Wherein, Z is a hydrocarbon chain having 3 to 6 main chain carbon atoms, the hydrocarbon chain is unsubstituted or substituted and may be part of a carbocyclic ring, a heterocyclic ring or an aromatic ring or a heteroaromatic ring. Preferably, the total number of carbon atoms of the alkanol of formula (III) does not exceed 12.

2. The method according to claim 1, characterized in that The compound of formula (II) is selected from 1,3-cyclobutanedione, 2,2,4,4-tetramethyl-1,3-cyclobutanedione and 2,2,4,4-dicyclopentylidene-1,3-cyclobutanedione.

3. The method according to claim 1 or 2, characterized in that: The alkanol of formula (III) is selected from 1,3-propylene glycol, 2-methyl-1,3-propylene glycol, 2,2-dimethyl-1,3-propylene glycol, 1,2,3-propanetriol, diglycerol, 3-mercaptopropane-1,2-diol, dithiothreitol, 1,1,1-trimethylolpropane, 1,2-butanediol, 1,3-butanediol, 2,4-butanediol, 2,4-dimethyl-1,3 -Butanediol, pentaerythritol, cyclohexane-1,2-diol, 1,4-dioxane-2,3-diol, 1,2,3-butanetriol, 1,3,4-butanetriol, 1,2,3-heptanetriol, 4-menthane-1,7,8-triol, 3-butene-1,2-diol, benzene-1,2-diol, 3-chlorocatechol, indan-1,2-diol, tartaric acid, pentose and hexose sugars.

4. The method according to any one of claims 1 to 3, characterized in that: Step S1 is carried out in the presence of at least one acid; The acid is selected from at least one of Bronsted acid, Lewis acid, and acidic ion exchanger, preferably Bronsted acid; Preferably, the amount of the acid added is 1 to 10% of the moles of the compound of formula (II) based on the moles of hydrogen ions of the acid; The Bronsted acid is preferably selected from trifluoroacetic acid, formic acid, hydrochloric acid, sulfuric acid, nitric acid, acidic pyridinium salts and p-toluenesulfonic acid; The acidic ion exchanger is preferably a macroporous strongly acidic polystyrene resin with a specific surface area of ​​40 to 70 m 2 / g, pore volume 0.2~0.5mL / g, H + The exchange capacity is ≥1 mmol / g, preferably a macroporous sulfonic acid polystyrene resin, more preferably at least one of A15, A35, A45, A70, D005, D009, and DNW-II resins.

5. The method according to any one of claims 1 to 4, characterized in that: The transition metal catalyst, wherein the transition metal is selected from Ru, Co, Ir, Rh, Ni, Pd and Pt, preferably, the transition metal is Ru; more preferably, the transition metal catalyst is a ruthenium-carbon catalyst; Preferably, the amount of transition metal catalyst added is 0.5 to 40%, preferably 15 to 30%, based on the molar number of transition metal.

6. The method according to any one of claims 1 to 5, characterized in that: The reduction reaction in step S1 is carried out in the presence of water; preferably, the reaction is carried out in the presence of 100 to 1000 times the molar number of the transition metal.

7. The method according to any one of claims 1 to 6, characterized in that: The reduction reaction temperature in step S1 is 30°C to 250°C, preferably 50°C to 150°C, and more preferably 100°C to 150°C.

8. The method according to any one of claims 1 to 7, characterized in that: The hydrogen pressure of the reduction reaction in step S1 is 0 to 30 MPaG, preferably 5 to 20 MPaG, and more preferably 10 to 15 MPaG.

9. The method according to any one of claims 1 to 8, characterized in that: The cis-trans ratio c / t of the compound of formula (I) and the molar ratio n of the added alkanol of formula (III) to that of formula (II) satisfy the following relationship: 0.5411+0.2338*n≤c / t≤0.5414*e 0.5922*n 。 10. The method according to any one of claims 1 to 9, characterized in that: The reaction further comprises step S2: separating the reaction mixture obtained in step S1 to obtain the compound of formula (I); preferably, the separation method is distillation, crystallization, extraction, adsorption or a combination of these methods.

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