Preparation method of biomass-based 2,2'-bistetrahydrofuran-2,2'-dicarboxylic acid and its derivative esters
By using a photocatalytic method to carry out CC coupling reaction using semiconductor catalysts under ultraviolet light or visible light, the problem of converting biomass-based 2-tetrahydrofuroic acid derivatives into 2,2′-bis-tetrahydrofuran-2,2′-dicarboxylic acid was solved, achieving efficient, environmentally friendly catalytic conversion and highly selective preparation.
Patent Information
- Application Number
- CN202311160574.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-11
- Publication Date
- 2025-09-09
- Estimated Expiration
- 2043-09-11
AI Technical Summary
Existing technologies make it difficult to efficiently convert biomass-based 2-tetrahydrofuroic acid and its derivatives into 2,2′-bis-tetrahydrofuran-2,2′-dicarboxylic acid and its derivatives, and lack environmentally friendly and efficient catalytic methods.
A photocatalytic method is adopted, using semiconductor catalysts such as titanium dioxide, precious metal-loaded titanium dioxide, etc., to carry out CC coupling reaction under ultraviolet light or visible light irradiation to convert 2-tetrahydrofuroic acid and its derivatives into 2,2'-bis-tetrahydrofuran-2,2'-dicarboxylic acid and its derivatives.
The preparation of 2,2′-bistetrahydrofuran-2,2′-dicarboxylic acid and its derivatives with high selectivity and high yield is achieved. The products can be directly used as polyester monomers. The catalytic system is simple and environmentally friendly.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the field of chemistry, and in particular relates to a method for preparing a biomass-based polyester monomer (2,2'-bistetrahydrofuran-2,2'-dicarboxylic acid and its derivative esters). Background Art
[0002] Biomass, including cellulose, hemicellulose, and lignin, is Earth's largest renewable carbon resource. Using biomass as a raw material to produce renewable polymers can effectively reduce fossil resource consumption. The pentoses obtained from the depolymerization of hemicellulose can be further dehydrated to produce furfural. Due to its relatively simple preparation method, furfural has been produced on a large scale since 1923, and currently global production of furfural is approximately 250,000 tons per year.
[0003] 2-Tetrahydrofuroic acid and its derivatives can be prepared from furfural through oxidative esterification and hydrogenation reactions and are important derivatives of furfural. The present invention aims to develop a method for converting 2-tetrahydrofuroic acid and its derivatives into 2,2′-bistetrahydrofuran-2,2′-dicarboxylic acid and its derivatives. 2,2′-bistetrahydrofuran-2,2′-dicarboxylic acid and its derivatives can be used directly as polyester monomers. This method utilizes a photocatalytic method, using a semiconductor catalyst to carry out a CC coupling reaction under ultraviolet or visible light irradiation to convert 2-tetrahydrofuroic acid and its derivatives into 2,2′-bistetrahydrofuran-2,2′-dicarboxylic acid and its derivatives. This method has high coupling efficiency and product yield, and has excellent application prospects. Summary of the Invention
[0004] The present invention aims to provide a method for preparing biomass-based polyester monomers (2,2′-bistetrahydrofuran-2,2′-dicarboxylic acid and its derivatives). The present invention also provides a catalyst for converting 2-tetrahydrofuroic acid and its derivatives into 2,2′-bistetrahydrofuran-2,2′-dicarboxylic acid and its derivatives.
[0005] The technical solution of the present invention:
[0006] The invention relates to a method for preparing biomass-based 2,2'-bis-tetrahydrofuran-2,2'-dicarboxylic acid and its derivatives. The method adopts a photocatalytic method to carry out a CC coupling reaction using a semiconductor catalyst under the irradiation of ultraviolet light or visible light to convert 2-tetrahydrofuroic acid and its derivatives into 2,2'-bis-tetrahydrofuran-2,2'-dicarboxylic acid and its derivatives.
[0007] The structural formula of the 2-tetrahydrofuroic acid and its derivative esters is The structural formula of the product 2,2′-bis-tetrahydrofuran-2,2′-dicarboxylic acid and its derivative ester is
[0008] The wavelength range of the ultraviolet light or visible light is 300-800 nm.
[0009] The semiconductor catalysts include titanium series (titanium dioxide, excessive noble metal or noble metal loaded titanium dioxide Cu / TiO2, Au / TiO2, Ru / TiO2, etc.), bismuth series (bismuth oxide, bismuth trioxide, bismuth tungstate and transition metal or noble metal loaded bismuth tungstate, etc.), cadmium series (cadmium oxide, cadmium sulfide, cadmium carbonate and transition metal or noble metal loaded cadmium oxide, cadmium sulfide, etc.).
[0010] The reaction temperature of this system is 10-30°C; the reaction time is 0.5-48h; the mass ratio of the semiconductor catalyst to 2-tetrahydrofuroic acid and its derivative ester is: 0.1-10wt%.
[0011] A solvent is added or not added during the reaction, and the solvent used is one or more of toluene, o-xylene, acetonitrile, dichloromethane, and dimethyl sulfoxide; stirring is performed during the reaction.
[0012] Beneficial effects of the present invention:
[0013] The present invention converts biomass-based 2,2′-bis-tetrahydrofuran-2,2′-dicarboxylic acid and its derivative esters into 2,2′-bis-tetrahydrofuran-2,2′-
[0014] The dicarboxylic acid and its derivative esters can be directly used as polyester monomers. The present invention employs a photocatalytic method, using semiconductor materials such as titanium dioxide as photocatalysts, which is environmentally friendly. The catalytic system of the present invention is simple and efficient, using a small amount of catalyst to highly selectively convert 2,2'-bistetrahydrofuran-2,2'-dicarboxylic acid and its derivative esters into 2,2'-bistetrahydrofuran-2,2'-dicarboxylic acid and its derivative esters in a short period of time. DETAILED DESCRIPTION
[0015] The present invention is described below by means of specific examples, but the present invention is not limited to these examples:
[0016] Example 1-14: 0.5 mmol of methyl 2-tetrahydrofuroate, 5 mg of titanium dioxide, and 2 mL of solvent (no solvent was added in Example 1) were added to a 10 mL photoreactor. The reactor was sealed and the reaction temperature was at room temperature. The reaction was carried out under 365 nm light irradiation for a predetermined time. The resulting sample was qualitatively analyzed by gas chromatography-mass spectrometry, and quantitatively analyzed by gas chromatography. The results are shown in Table 1.
[0017] Table 1 Optimization of reaction conditions
[0018]
[0019]
[0020] Analysis of the results in Table 1 shows that the optimal solvent for converting methyl 2-tetrahydrofuroate to dimethyl 2,2′-bis-tetrahydrofuran-2,2′-dicarboxylate using titanium dioxide is acetonitrile. The optimized reaction conditions are a 40 W power lamp. After 12 hours, the conversion rate of methyl 2-tetrahydrofuroate is 96%, and the selectivity of dimethyl 2,2′-bis-tetrahydrofuran-2,2′-dicarboxylate is 97%.
[0021] In Example 15-25, 0.5 mmol of methyl 2-tetrahydrofuroate, a predetermined amount of catalyst, and 2 mL of acetonitrile were added to a 10 mL photoreactor. The reaction was carried out in a sealed manner at room temperature under illumination for a predetermined time. The resulting samples were qualitatively analyzed by gas chromatography-mass spectrometry, and quantitatively analyzed by gas chromatography. The results are shown in Table 2.
[0022] Table 2 Effects of different catalysts on catalytic reactions
[0023]
[0024]
[0025] Analysis of the results in Table 2 shows that titanium dioxide has good catalytic activity, and precious metal-loaded titanium dioxide has improved activity, and can operate in the visible light range. Catalysts such as bismuth tungstate and cadmium oxide also have good catalytic effects.
[0026] In Examples 30-41, a certain amount of different reaction substrates, 5 mg of TiO2, and 2 mL of acetonitrile were added to a 10 mL photoreactor. The reactor was sealed and the reaction temperature was set at room temperature under 365 nm 40 W illumination for a certain time. The resulting samples were qualitatively analyzed by gas chromatography-mass spectrometry, and quantitatively analyzed by gas chromatography. The results are shown in Table 3.
[0027] Table 3 Catalytic reaction effects of different reaction substrates and their dosages
[0028]
[0029]
[0030] Analysis of the results in Table 3 shows that all eight reaction substrates tested have good reactivity.
[0031] The qualitative analysis of the product was carried out by gas chromatography-mass spectrometry and the retention time was compared with that of the standard sample; the quantitative analysis was carried out by gas chromatography with internal standard method.
[0032] Conversion rate = (number of moles of 2-tetrahydrofuroic acid and its derivatives converted / number of moles of 2-tetrahydrofuroic acid and its derivatives input) × 100%
[0033] Selectivity=(the number of moles of 2,2′-bistetrahydrofuran-2,2′-dicarboxylic acid and its derivatives / the number of moles of converted 2-tetrahydrofuroic acid and its derivatives)×100%.
Claims
1. A method for preparing biomass-based 2,2'-bis-tetrahydrofuran-2,2'-dicarboxylic acid and its derivative esters, characterized in that: The method adopts a photocatalytic method and uses a semiconductor catalyst to carry out a CC coupling reaction under the irradiation of ultraviolet light or visible light to convert 2-tetrahydrofuroic acid and its derivative esters into 2,2'-bis-tetrahydrofuran-2,2'-dicarboxylic acid and its derivative esters; The structural formula of the 2-tetrahydrofuroic acid and its derivative esters is The structural formula of the product 2,2'-bis-tetrahydrofuran-2,2'-dicarboxylic acid and its derivative ester is The semiconductor catalyst is titanium dioxide, gold-loaded titanium dioxide, platinum-loaded titanium dioxide, palladium-loaded titanium dioxide, bismuth tungstate or cadmium oxide.
2. The method for preparing biomass-based 2,2'-bis-tetrahydrofuran-2,2'-dicarboxylic acid and its derivative esters according to claim 1, characterized in that: The wavelength range of the ultraviolet light or visible light is 300-800 nm.
3. The method for preparing biomass-based 2,2'-bis-tetrahydrofuran-2,2'-dicarboxylic acid and its derivative esters according to claim 1, characterized in that: The reaction temperature is 10-30°C; the reaction time is 0.5-48h.
4. The method for preparing biomass-based 2,2'-bis-tetrahydrofuran-2,2'-dicarboxylic acid and its derivative esters according to claim 1, characterized in that: The mass ratio of the semiconductor catalyst to the 2-tetrahydrofuroic acid and its derivative ester is 0.1-10wt%.
5. The method for preparing biomass-based 2,2'-bis-tetrahydrofuran-2,2'-dicarboxylic acid and its derivative esters according to claim 1, characterized in that: A solvent is added or not added during the reaction, and the solvent used is one or more of toluene, o-xylene, acetonitrile, dichloromethane, and dimethyl sulfoxide; stirring is performed during the reaction.