Preparation method of bio-based trans, trans-muconic acid

Abstract

The invention discloses a preparation method of bio-based trans, trans-muconic acid. Comprising the following steps: mixing a raw material containing galactose diacid with a catalyst, and reacting to obtain a product containing trans, trans-muconic acid; the catalyst is selected from at least one of ammonium paramolybdate, ammonium orthomolybdate, potassium heptamolybdate, sodium molybdate, sodium molybdate and molybdic acid. Compared with a traditional method for synthesizing trans, trans-muconic acid, the method provided by the invention has the advantages of simple steps, low cost and high conversion rate selectivity. Compared with traditional fossil energy-based raw materials, the reaction raw materials are derived from biomass, and the sustainable development view and the dual-carbon concept are met.

Description

Technical Field

[0001] This application relates to a method for preparing bio-based trans- and trans-mucoconic acid, belonging to the field of chemical engineering. Background Technology

[0002] Mucoconic acid is a very important high-value-added chemical. It exhibits strong absorption of 260nm ultraviolet light and is primarily used in UV-protective agents and special military products. For example, some countries have widely adopted it as a UV absorber in sunscreens, especially as a key additive in beach and sea bath cosmetics. In the military industry, mucoconic acid is used in stealth aircraft coatings, special photosensitive resins, and electronic materials. Simultaneously, mucoconic acid is also an important platform molecule, capable of generating important chemical raw materials such as adipic acid and terephthalic acid through subsequent reactions.

[0003] Mucoconic acid can be synthesized from both traditional fossil fuels and bio-based feedstocks. Current mature synthetic processes for cis,cis-mucoconic acid primarily utilize the fermentation and degradation of carbohydrates. In 1994, scientists used *E. coli* as the starting strain and employed 1,2-dioxygenase, protocatechuic acid decarboxylase, and 3-dehydroshikimate dehydratase to catalyze the process, using glucose as the carbon source to synthesize mucoconic acid. Later, other researchers continuously improved the process, eventually cultivating a yeast strain 24 times more potent than the starting strain, producing cis,cis-mucoconic acid at concentrations as high as 141 mg / L. Subsequent strain cultivation and screening revealed that cis,cis-mucoconic acid can be converted to cis,trans-mucoconic acid through fermentation. However, the production of trans,trans-mucoconic acid requires a metal-catalyzed hydrogenation-dehydroisomerization reaction, a cumbersome and costly process. Therefore, developing a one-step synthesis of trans,trans-mucoconic acid from biomass has become an urgent problem to solve.

[0004] Galactobionic acid, also known as mucoagulant or viscous acid, is an important pharmaceutical intermediate widely used in high-end cosmetics to remove lead and mercury from the skin. Galactobionic acid possesses strong adhesive properties, allowing it to bind with lead and mercury in skin-friendly cosmetics (its efficacy surpasses that of EDTA). Galactobionic acid can be synthesized by oxidizing galactose or galactitol with nitric acid, or obtained through fermentation of fruit peels, making it an important bio-based raw material. Summary of the Invention

[0005] This application utilizes galactoic acid derived from biomass as a raw material to obtain trans-,trans-mucoconic acid via a one-step dehydration and deoxygenation reaction. The method exhibits high conversion rate, good stability, low cost, and ease of large-scale preparation. The conversion rate can reach 80%, and the selectivity exceeds 90%.

[0006] According to one aspect of this application, a method for preparing bio-based trans- and trans-mucoconic acid is provided, comprising the following steps:

[0007] The raw material containing galactosic acid is mixed with a catalyst and reacted in a sealed container to obtain a product containing trans- and trans-mucoconic acid.

[0008] The catalyst is selected from at least one of ammonium paramolybdate, ammonium orthomolybdate, potassium heptamolybdate, sodium molybdate, sodium molybdate, and molybdic acid.

[0009] The raw materials also contain reducing agents and solvents;

[0010] The reducing agent is selected from at least one of sodium sulfite, triphenylphosphine, and n-butanol;

[0011] The solvent is selected from at least one of methanol, ethanol, isopropanol, n-butanol, 3-pentanol, n-octanol, acetone, dichloromethane, acetonitrile, 1,4-dioxane, toluene, and tetrahydrofuran.

[0012] In the raw materials,

[0013] The molar concentration of the galactosic acid is 0.01–0.2 M;

[0014] Optionally, the molar concentration of the galactoic acid is any value among 0.01M, 0.05M, 0.1M, and 0.2M, or a range between any two.

[0015] The molar amount of the reducing agent is 0.5 to 4 times the molar amount of galactosic acid;

[0016] Optionally, the molar amount of the reducing agent is any value among 0.5 times, 1 time, 2 times, 3 times, and 4 times the molar amount of galactobionic acid, or any value between both.

[0017] The molar amount of the catalyst is 0.01 to 0.05 times the molar amount of galactosic acid.

[0018] Optionally, the molar amount of the catalyst is any value among 0.01 times, 0.02 times, 0.03 times, 0.04 times, and 0.05 times the molar amount of galactosic acid, or a range between any two.

[0019] The reaction temperature is 100–220°C;

[0020] Optionally, the reaction temperature is 160–180°C;

[0021] Optionally, the temperature of the reaction is any value among 160°C, 170°C, and 180°C, or a range between any two.

[0022] The reaction time is 2 to 48 hours.

[0023] Optionally, the reaction time is 6 to 12 hours.

[0024] Optionally, the reaction time is any value among 6h, 8h, 10h, and 12h, or a range between any two.

[0025] The reaction is carried out at atmospheric pressure.

[0026] Inert gases are used for purging during the reaction;

[0027] The inactive gas is selected from at least one of nitrogen, argon, and helium.

[0028] The reaction is a dehydration and deoxygenation reaction (DODH reaction).

[0029] The reaction process is as follows:

[0030]

[0031] The beneficial effects that this application can produce include:

[0032] 1. Compared with traditional methods for synthesizing trans-, trans-mucoconic acid, the present invention has simple steps, low cost, and high conversion selectivity.

[0033] 2. Compared to traditional fossil fuel-based raw materials, the reaction raw materials are derived from biomass, which is in line with the concept of sustainable development and the dual-carbon principle. Attached Figure Description

[0034] Figure 1 This is the liquid chromatogram of trans-trans-mucoconic acid obtained in Example 1 of this application. Detailed Implementation

[0035] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0036] Unless otherwise specified, the raw materials and catalysts used in the embodiments of this application were all purchased commercially.

[0037] Example 1:

[0038] 1.05 g of galactopyric acid, 1.31 g of triphenylphosphine, and 0.00903 g of molybdic acid were added to a high-pressure reactor containing 100 mL of ethanol. The reactor was purged with nitrogen three times and heated to 180 °C in an oil bath for 6 h. After the reaction was completed, the conversion rate of galactopyric acid and the selectivity of trans- and trans-mucoconic acid were analyzed by liquid chromatography. The conversion rate was 80%, and the selectivity of trans- and trans-mucoconic acid was 95%.

[0039] Example 2:

[0040] 1.05 g of galactopyric acid, 2.63 g of triphenylphosphine, and 0.0363 g of sodium molybdate were added to a high-pressure reactor containing 100 mL of toluene. The reactor was purged with nitrogen three times and heated to 160 °C in an oil bath for 8 h. After the reaction was completed, the conversion rate of galactopyric acid and the selectivity of trans- and trans-mucoconic acid were analyzed by liquid chromatography. The conversion rate was 82%, and the selectivity of trans- and trans-mucoconic acid was 95%.

[0041] Example 3:

[0042] 2.1 g of galactosic acid and 0.0392 g of ammonium molybdate were added to a high-pressure reactor containing 100 mL of n-butanol. The reactor was purged with nitrogen three times and heated to 180 °C in an oil bath for 12 h. After the reaction was completed, the conversion rate of galactosic acid and the selectivity of trans- and trans-mucoconic acid were analyzed by liquid chromatography. The conversion rate was 80% and the selectivity of trans- and trans-mucoconic acid was 95%.

[0043] Example 4:

[0044] 2.1 g of galactoic acid, 2.52 g of sodium sulfite, and 0.416 g of ammonium molybdate were added to a high-pressure reactor containing 100 mL of 1,4-dioxane. The reactor was purged with nitrogen three times and heated to 140 °C in an oil bath for 12 h. After the reaction, the conversion rate of galactoic acid and the selectivity of trans- and trans-mucoconic acid were analyzed by liquid chromatography. The conversion rate was 88%, and the selectivity of trans- and trans-mucoconic acid was 96%.

[0045] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

Claims

1. A method for preparing bio-based trans- and trans-mucoconic acid, characterized in that, Includes the following steps: The raw material containing galactosic acid is mixed with a catalyst and reacted in a sealed container to obtain a product containing trans- and trans-mucoconic acid. The catalyst is selected from at least one of ammonium paramolybdate, ammonium orthomolybdate, potassium heptamolybdate, sodium molybdate, sodium molybdate, and molybdic acid.

2. The preparation method according to claim 1, characterized in that, The raw materials also contain reducing agents and solvents; The reducing agent is selected from at least one of sodium sulfite, triphenylphosphine, and n-butanol; The solvent is selected from at least one of methanol, ethanol, isopropanol, n-butanol, 3-pentanol, n-octanol, acetone, dichloromethane, acetonitrile, 1,4-dioxane, toluene, and tetrahydrofuran.

3. The preparation method according to claim 2, characterized in that, In the raw materials, The molar concentration of the galactosic acid is 0.01–0.2 M; The molar amount of the reducing agent is 0.5 to 4 times the molar amount of galactosic acid; The molar amount of the catalyst is 0.01 to 0.05 times the molar amount of galactosic acid.

4. The preparation method according to claim 1, characterized in that, The reaction temperature is 100–220°C; The reaction time is 2 to 48 hours.

5. The preparation method according to claim 1, characterized in that, The reaction temperature is 160–180°C; The reaction time is 6 to 12 hours.

6. The preparation method according to claim 1, characterized in that, The reaction is carried out under an inert atmosphere.

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