CN115304462B - Method for producing glycolaldehyde - Google Patents

Abstract

The application relates to a method for preparing glycolaldehyde by formaldehyde condensation, which uses amidine or immobilized amidine and triazole salt as catalysts and alkali as reaction auxiliary agent to convert formaldehyde into glycolaldehyde, glyceraldehyde and low-carbon sugar. Raw formaldehyde in the reaction system is cheap and easy to obtain, the catalyst synthesis is simple, and the target product glycolaldehyde has high yield. The production process is simple, easy to operate and environment-friendly, and creates good conditions for industrial mass production of products.

Description

A kind of method for producing glycolaldehyde

Technical field

The invention relates to the field of organic compound synthesis, and specifically relates to a method for preparing glycolaldehyde by condensation of formaldehyde.

Background technique

Glycolaldehyde (HOCH ₂ CHO, Glycolaldehyde) is the simplest sugar. It reacts with acrolein to form ribose, which is an important component of RNA. It is a very critical sugar molecule in the origin of life. There are two functional groups, aldehyde group and hydroxyl group, in its molecule. It has the dual properties of alcohol and aldehyde and has active chemical properties. As an important chemical intermediate, it is widely used in food, medicine and health, chemical industry and other industries.

The current production methods of glycolaldehyde mainly include formaldehyde hydroformylation, selective formose reaction, aqueous pyrolysis of sugar alcohols and nitrogen-containing heterocyclic carbene catalysis. The formaldehyde hydroformylation reaction based on rhodium catalysis has mild reaction conditions but still requires high pressure, and rhodium is expensive; the selective formose reaction and the aqueous pyrolysis of sugar alcohols although the catalyst inorganic base is cheap and easy to obtain, but requires strict The reaction conditions are controlled and a large amount of wastewater is produced. Development must solve the problem of wastewater treatment. In comparison, N-heterocyclic carbene catalyzes the self-condensation of formaldehyde, using formaldehyde from a wide range of sources and cheap prices as starting materials. It has high catalytic efficiency, good selectivity, easy separation of the product and good stability, and has the most development and application prospects. .

Teles et al. catalyzed the formaldehyde reaction using stable carbenes obtained from thiazolium salts, imidazole salts and triazolium salts, and found that glycolaldehyde, a catalyst based on 1,4-disubstituted-1H-1,2,4-triazolium salts, was the main product. , and proposed the reaction mechanism (Helv. Chim. Acta, 1996, 79: 61-83). In US 5508422, 2-p-nitrophenyl-1-methyl-1,2,4-triazole iodide is used as a catalyst to catalyze the formaldehyde reaction, tetrahydrofuran is used as the solvent, and triethylamine of the same material as the catalyst is used as a co-base. After reaction at 80°C for 2 hours under nitrogen protection, the yield of product glycolaldehyde was 46.2%, and the yields of by-products dihydroxyacetone (DHA) and glyceraldehyde were 0.7% and 4.1% respectively. US 5298668 studied the formaldehyde condensation reaction catalyzed by the Nitron structure. DMF was used as the solvent, equal amounts of Nitron and co-base triethylamine were added, and stirred at 80°C for 1 hour under nitrogen protection. The glycolaldehyde yield could reach 65.2%, and the glyceraldehyde yield could reach 65.2%. 16.0%, DHA yield 0.8%, four-carbon sugar yield 1.2%.

Although the use of triazolium salt catalysts to catalyze the condensation of formaldehyde to form glycolaldehyde has been studied earlier, they are all homogeneous catalysts. The steps in the catalyst synthesis are complicated, the yield is low, and the reaction is harsh, which increases the possibility of condensation of formaldehyde to form glycolaldehyde. cost. Therefore, it is necessary to find a cheap amidine as a catalyst, or to achieve recycling of supported amidine and triazolium salt catalysts, to explore a suitable process for formaldehyde condensation to produce glycolaldehyde, to reduce production costs, and to provide industrial-scale production and commercialization of products. culture has created good conditions.

Contents of the invention

This application relates to a method for preparing glycolaldehyde (GA) through the condensation of formaldehyde, which is characterized by: using amidine or solid-supported amidine and triazole salt as catalyst, and using alkali as reaction aid in an organic solvent to convert formaldehyde into Glycolaldehyde, glyceraldehyde and other low-carb sugars.

In a preferred embodiment, the catalyst is amidine, immobilized amidine and triazole salt. The carrier used for solid support is selected from silica gel, montmorillonite (Na-MMT), polystyrene, and molecular sieves; the amidine composition is R ³ N ⁺ H ₂ NHCR ² NR ¹ X ^- . The triazole salt composition is CHN ⁺ R ³ N ⁺ CR ² NR ¹ X ^- Y ^- /carrier. Among them, R ¹ , R ² , and R ³ each independently represent different substituted functional groups. Note that in C _n, n is the number of carbon atoms in the alkane. The R group is selected from H, halogenated group, C ₁ -C ₃₀ alkyl group, C ₁ -C ₃₀ alkoxy group, C ₁ -C ₂₀ amide group, C ₁ -C ₁₀ alkyl mono- or disubstituted amino group, C ₁ -C ₁₀ mercapto-containing alkyl group, C ₁ -C _10- containing nitroalkyl group, C ₁ -C ₁₀ -containing cyanoalkyl group, C ₆ -C ₅₀ aryl group, C ₇ -C ₅₀ heteroaryl group, C ₃ -C ₅₀ heterocycloalkyl group or Heterocycloalkenyl, C ₇ -C ₅₀ aralkyl, C ₄ -C ₅₀ heteroaralkyl or C ₄ -C ₅₀ heterocycloalkylalkyl or heterocycloalkenyl alkyl. X- and Y- represent anions, and the anions are selected from halide anions, nitrate ions, perchlorate ions, hydrogen sulfate ions, acetate ions, benzenesulfonate ions, methanesulfonate ions, and p-toluenesulfonate ions. and tetrafluoroborate ion. Anions mainly affect the physical properties of triazolium salts.

In a preferred embodiment, the preparation method of the catalyst is as follows: dissolve alkylamine or arylamine in hydrochloric acid, mix and stir with a certain amount of carbon tetrachloride solution of alkyl acid chloride or aryl acid chloride, and gradually add hydrogen dropwise The sodium oxide solution completely neutralizes the hydrogen chloride in the system. After the reaction, the precipitate is filtered to obtain the product amide; the amide is stirred and refluxed with excess thionyl chloride, and the product is rotary evaporated to obtain amide chloride; add amide chloride, Alkyl hydrazine or aryl hydrazine and triethylamine react under certain conditions, and the volatile matter is removed from the product to obtain amidine; a certain amount of acetic anhydride and formic acid are mixed, heated and transferred to the amidine through a cannula for reaction, and an organic acid aqueous solution is added and dichloromethane to obtain triazolium salt.

In a preferred embodiment, a certain amount of amidine or triazolium salt and chloroorganosilane are stirred and heated in an organic solvent for a period of time and then cooled, the solid is washed and dried, mixed with silica gel or molecular sieve, and stirred and heated in an organic solvent to obtain Silica gel or molecular sieve immobilized amidine or triazolium salt catalyst. The immobilized catalyst is obtained by replacing different anions with halogenated anions of synthetically immobilized amidine or triazolium salt catalysts. The operating conditions during immobilization affect the yield of the immobilized catalyst.

In a preferred embodiment, the preparation method of the montmorillonite or polystyrene-immobilized amidine or triazolium salt catalyst is as follows: adding a certain amount of amidine or triazolium salt and montmorillonite or halogenated polystyrene. It is stirred and heated in a solvent and then cooled. After the solid is washed and dried, a montmorillonite or polystyrene-immobilized catalyst is obtained. Through the replacement of different anions with the halogenated anions of the synthesized immobilized triazolium salt catalyst, a montmorillonite or polystyrene immobilized amidine or triazolium salt catalyst is obtained. Among them, the operating conditions during immobilization affect the yield of the immobilized catalyst, and the triazolium salt ions are immobilized on the montmorillonite through ion exchange.

In a preferred embodiment, the amount of catalyst supported per gram of carrier is 0.001 to 20.0 mmol, and the mass ratio of amidine to triazole salt is 0 to 100. An appropriate increase in the loading amount of active components helps to improve the catalytic activity.

In a preferred embodiment, the formaldehyde raw material used is a formaldehyde aqueous solution with a mass fraction of 0.1 to 80%, or it can be a formaldehyde aqueous solution containing an organic solvent, paraformaldehyde, trimerformaldehyde, paraformaldehyde, or depolymerized trimerformaldehyde. Organic solvents. The carbene catalyst is reversibly deactivated when exposed to water. When using formaldehyde aqueous solution as raw material, an organic solvent insoluble in water must be used.

In a preferred embodiment, the auxiliary base is any one or more of Brønsted base, Lewis base, metal complex, amino acid, solid base, and ion exchange resin.

In a preferred embodiment, the reaction system solvent is a C ₁ -C ₃₀ alcohol compound, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyl sulfoxide Propylformamide, N,N-dibutylformamide, N,N-dipentylformamide, N-alkylpyrrolidone, dichloromethane, tetrahydrofuran, 1,4-dioxane, acetonitrile, sulfolane, ethyl acetate Any one or any combination of esters, cyclohexane, benzene, xylene, o-xylene, m-xylene, p-xylene, 4-methyl-2-pentanone, cyclohexanone, ionic liquids .

In a preferred embodiment, the reaction is carried out under aerobic or anaerobic conditions. The anaerobic conditions refer to a vacuuming method or an inert gas to exclude the air in the container. The inert gas is nitrogen, carbon dioxide or helium.

In a preferred embodiment, the reaction conditions are as follows: the molar ratio of the catalyst to the raw material formaldehyde is 0-1000; the molar ratio of the catalyst to the auxiliary base is 0-1000, and the reaction is carried out at 0-350°C and 0-10MPa. Under suitable reaction conditions, the yields of glycolaldehyde and glyceraldehyde can reach 63% and 28%.

It can be seen from the above preferred embodiments of the present invention that the high value-added product glycolaldehyde is obtained by catalyzing the condensation of formaldehyde using formaldehyde as the raw material and the immobilized triazolium salt as the catalyst. The raw material formaldehyde is cheap and easy to obtain, the catalyst synthesis is simple and easy to recover, and the yield of the target product glycolaldehyde is high. The production process involved in this application is simple, easy to operate, and environmentally friendly, creating good conditions for the industrial-scale production of the product.

Description of the drawings

Figure 1 shows the immobilized amidine: silica gel, montmorillonite (Na-MMT), polystyrene, and molecular sieve as carriers.

Figure 2 is a reaction schematic diagram of Examples 1-23.

Detailed ways

The present invention will be described in detail below with reference to examples, but those skilled in the art will understand that those skilled in the art can make certain changes or modifications to the present invention based on the disclosure of the present invention and their own technical knowledge. Therefore, the scope of the present invention is not limited to the following embodiments, but should be defined only by the claims.

Example 1-23

Place formaldehyde (30mmol) into the reaction kettle, then add N,N-dimethylformamide (10ml) to the reaction kettle, add amidine catalyst I-K (0.15mmol, as shown in Figure 2) or silica gel-immobilized trinitrogen Azole catalyst A-H (1g, 0.15mmol triazole salt/g carrier, as shown in Figure 2), additive triethylamine (0.70mmol). Install the reaction kettle, stir and react at a temperature of 0 to 300°C and a pressure of 0 to 10MPa for 1 to 1000 minutes. After the reaction was completed, the generated glycolaldehyde and glyceraldehyde were detected by liquid chromatography. The results are shown in Table 1.

Table 1. Effects of different catalysts on the condensation of formaldehyde to glycolaldehyde at different temperatures and times.

Examples 24-43

Take paraformaldehyde (30mmol), silica gel-immobilized amidine K and triazolium salt catalyst A with different solid loading amounts, additives triethylamine (2.00mmol), and N,N-dimethylformamide (10ml) and add them to Reactor, install the reactor, stir and react for 60 minutes at a temperature of 0 to 340°C and a pressure of 0 to 10MPa. After the reaction was completed, liquid chromatography was used to detect the generated glycolaldehyde and glyceraldehyde. The results are shown in Tables 2 and 3.

Table 2. Effects of catalysts with different solid loading amounts in catalyzing the condensation of formaldehyde to glycolaldehyde.

Table 3. Effects of different amounts of amidine catalyzing the condensation of formaldehyde to glycolaldehyde

Examples 44-51

Take organic solvent solutions or formaldehyde aqueous solutions of different concentrations (the amount of formaldehyde is 30mmol), silica gel-supported amidine J, K or triazole salt catalysts A, B (1g, 0.15mmol catalyst/g silica gel), additives Add triethylamine (0.70mmol) to the reaction kettle, install the reaction kettle, then fill it with nitrogen, and stir and react at a temperature of 80 to 200°C for 60 minutes. After the reaction was completed, the generated glycolaldehyde and glyceraldehyde were detected by liquid chromatography. The results are shown in Table 4.

Table 4. Effect of solid-supported catalysts in catalyzing the condensation of formaldehyde solutions with different concentrations into glycolaldehyde

Examples 52-68

Take paraformaldehyde (30mmol), silica gel-immobilized amidine K (0.15mmol) or triazolium salt catalyst A (1g, 0.15mmol triazolium salt/g silica gel), additive triethylamine (0.75mmol), different The reaction solvent (10 ml) was added to the reaction kettle, the reaction kettle was installed, then filled with nitrogen, and stirred for 60 minutes at a temperature of 80°C. After the reaction was completed, the generated glycolaldehyde and glyceraldehyde were detected by liquid chromatography. The results are shown in Table 5.

Table 5. Effect of catalyzing the condensation of formaldehyde to glycolaldehyde in different reaction solvents

Table 5 Effects of Catalysts A and K in catalyzing the condensation of formaldehyde to glycolaldehyde in different reaction solvents (continued)

Examples 69-74

Take paraformaldehyde (30mmol), silica gel-immobilized amidine (1g, 0.15mmol amidine/g silica gel) or triazolium salt catalyst (1g, 0.15mmol triazolium salt/g silica gel), different auxiliary bases (0.75mmol ), N,N-dimethylformamide (15 ml) was added to the reaction kettle, the reaction kettle was installed, then filled with nitrogen, and the reaction was stirred at 50-90°C for 60 minutes. After the reaction was completed, the generated glycolaldehyde and glyceraldehyde were detected by liquid chromatography. The results are shown in Table 6.

Table 6 Catalysts supported on silica gel catalyze the condensation of formaldehyde to generate glycolaldehyde in different reaction solvents

Examples 75-82

Take formaldehyde aqueous solutions (30mmol) of different concentrations, amidine I-K (0.15mmol) or silica gel-immobilized triazolium salt catalyst A (1g, 0.15mmol triazolium salt/g silica gel), auxiliary triethylamine (0.70mmol), Add methyl isobutyl methanol (10 ml) as the reaction solvent to the reaction kettle, install the reaction kettle, and stir the reaction at a temperature of 80 to 200°C for 60 to 120 minutes. At the end of the reaction, the generated glycolaldehyde and glyceraldehyde were detected by liquid chromatography. The catalyst was washed and dried under nitrogen protection and reused. The results are shown in Table 7.

Table 7 Using methyl isobutyl carbinol as the solvent, catalysts A and I-K catalyze the condensation of formaldehyde aqueous solution to generate glycolaldehyde.

Claims (16)

1. A method for preparing glycolaldehyde by formaldehyde condensation is characterized in that: using amidine as catalyst, using alkali as reaction auxiliary agent in solvent to convert formaldehyde into glycolaldehyde and low-carbon sugar;

wherein the amidine composition is R ³ N ⁺ H ₂ NHCR ² NR ¹ X ^- Wherein R is ¹ 、R ² 、R ³ Each independently selected from C ₆ -C ₅₀ Aryl or C of (2) ₁ -C ₃₀ Alkyl, X ^- Represents an anion selected from the group consisting of halide anions, nitrate ions, perchlorate ions, bisulfate ions, acetate ions, benzenesulfonate ions, methanesulfonate ions, p-toluenesulfonate ions, and tetrafluoroborate ions;

wherein the conversion is carried out at a temperature ranging from 80 to 200 ℃;

wherein the base is triethylamine and the solvent is selected from DMF, butanol, dimethyl sulfoxide or methyl isobutyl carbinol; or the solvent is DMF and the base is selected from potassium carbonate, sodium oxalate or Amberlite IRA-400.

2. A method for preparing glycolaldehyde by formaldehyde condensation is characterized in that: using immobilized amidine and immobilized triazole salt as catalysts, and converting formaldehyde into glycolaldehyde and low-carbon sugar in a solvent by using alkali as a reaction auxiliary agent;

wherein the amidine composition is R ³ N ⁺ H ₂ NHCR ² NR ¹ X ^- Wherein R is ¹ 、R ² 、R ³ Each independently selected from C ₆ -C ₅₀ Aryl or C of (2) ₁ -C ₃₀ Alkyl, X ^- Represents an anion selected from the group consisting of halide anions, nitrate ions, perchlorate ions, bisulfate ions, acetate ions, benzenesulfonate ions, methanesulfonate ions, p-toluenesulfonate ions, and tetrafluoroborate ions;

the triazole salt is CHN ⁺ R ³ N ⁺ CR ² NR ¹ X ^- Y ^- A carrier; wherein R is ¹ 、R ² 、R ³ Each item is independentIs selected from H, halo, C ₁ -C ₃₀ Alkyl, C ₁ -C ₃₀ Alkoxy, C ₁ -C ₂₀ Amide group, C ₁ -C ₁₀ Amino, C, mono-or di-substituted by alkyl ₁ -C ₁₀ Containing mercaptoalkyl radicals, C ₁ -C ₁₀ Containing nitroalkyl groups, C ₁ -C ₁₀ Containing cyanoalkyl groups, C ₆ -C ₅₀ Aryl, C of (2) ₇ -C ₅₀ Heteroaryl, C ₃ -C ₅₀ Is a heterocycloalkyl or heterocycloalkenyl group, C ₇ -C ₅₀ Aralkyl of (C) ₄ -C ₅₀ Heteroaralkyl or C ₄ -C ₅₀ A heterocycloalkylalkyl or heterocycloalkenylalkyl group; x is X ^- 、Y ^- Represents an anion selected from the group consisting of halide anions, nitrate ions, perchlorate ions, bisulfate ions, acetate ions, benzenesulfonate ions, methanesulfonate ions, p-toluenesulfonate ions, and tetrafluoroborate ions;

wherein the conversion is carried out at a temperature ranging from 80 to 200 ℃ and a pressure ranging from 0.1 to 10 MPa.

3. The method of claim 2, wherein the carrier used for immobilization is selected from the group consisting of silica gel, montmorillonite, polystyrene, and molecular sieves.

4. The process according to claim 1 or 2, wherein the process for the preparation of amidines is as follows: dissolving alkylamine or arylamine in acid, mixing with a certain amount of alkyl acyl chloride or aryl acyl chloride solution, and separating precipitate after the reaction to obtain product amide; mixing amide and thionyl chloride for reaction to obtain an amide chloride product; then adding solvent, triethylamine, alkyl hydrazine or aryl hydrazine to react to obtain the amidine.

5. The method according to claim 1 or 2, wherein the formaldehyde is an aqueous formaldehyde solution with a mass fraction of 0.1-80%, an aqueous formaldehyde solution containing an organic solvent, paraformaldehyde, trioxymethylene, paraformaldehyde or a solution of trioxymethylene after depolymerization in an organic solvent.

6. The method of claim 2, wherein the base is any one or more of a bronsted base, a lewis base, a metal complex, an amino acid, and an ion exchange resin.

7. The process of claim 2, wherein the base is a solid base.

8. The method of claim 2, wherein the solvent is C ₁ -C ₃₀ Any one or a combination of any several of alcohol compounds, dimethyl sulfoxide, N-dimethylformamide, N-dimethylacetamide, N-dipropylformamide, N-dibutylformamide, N-dipentylcarboxamide, N-alkylpyrrolidone, methylene dichloride, tetrahydrofuran, 1, 4-dioxane, acetonitrile, sulfolane, ethyl acetate, cyclohexane, benzene, o-xylene, m-xylene, p-xylene, 4-methyl-2-pentanone, cyclohexanone and ionic liquid.

9. A process according to claim 1 or claim 2 wherein the conversion is carried out under aerobic or anaerobic conditions, the anaerobic conditions being either a vacuum process or an inert gas which removes air from the vessel, the inert gas comprising nitrogen, carbon dioxide or helium.

10. The method of claim 1 or 2, wherein the concentration of glycolaldehyde is between 0.001 and 100%.

11. The method of claim 1 or 2, wherein the low-carbon sugar comprises dihydroxyacetone, glyceraldehyde, or a C4-C8 sugar.

12. The process of claim 1, wherein the conversion is carried out at a pressure of 0 to 10MPa for a reaction time of 0.001 minutes to 200 hours.

13. The method of claim 2, wherein the reaction time of the conversion is 0.001 minutes to 200 hours.

14. The process according to claim 1 or 2, wherein the conversion conditions are such that the molar ratio of catalyst to raw formaldehyde is 0.005 to 100; the molar ratio of the catalyst to the auxiliary alkali is 0.0775-1000.

15. A process as claimed in claim 2 or 3, wherein the amount of catalyst supported per gram of carrier is from 0.001 to 20mmol, and the mass ratio of amidine to triazolium salt is

16. The method according to claim 2 or 3, wherein the mass ratio of amidine to triazole salt is