Method for synthesizing 3-mercaptopropionic acid by catalyzing acrylic acid and hydrogen sulfide through acidic molecular sieve

Abstract

The invention relates to a method for synthesizing 3-mercaptopropionic acid by catalyzing acrylic acid and hydrogen sulfide through an acidic molecular sieve, and belongs to the technical field of organic synthesis. In order to solve the problems of low selectivity and difficulty in regeneration of 3-mercaptopropionic acid prepared from an existing basic catalyst, the method comprises the following steps: firstly, pretreating a molecular sieve catalyst to obtain a required acidic molecular sieve catalyst; and mixing the acidic molecular sieve catalyst, acrylic acid and an organic solvent according to a certain mass volume ratio, introducing hydrogen sulfide to a certain pressure, heating to a reaction temperature, and reacting for a certain time to obtain 3-mercaptopropionic acid. The acidic molecular sieve used in the invention has the characteristics of high catalytic activity, high selectivity, high mechanical strength and reproducibility, and can catalyze the addition of acrylic acid and hydrogen sulfide to synthesize 3-mercaptopropionic acid in one step, the conversion rate of 3-mercaptopropionic acid is higher than 90%, the selectivity is higher than 85%, and the method has the characteristics of simple catalytic synthesis method, mild conditions and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing 3-mercaptopropionic acid by using an acidic molecular sieve to catalyze acrylic acid and hydrogen sulfide. Background Art

[0002] 3-Mercaptopropionic acid is an important organic synthesis intermediate, widely used in organic synthesis in medicine, pesticides and materials. The chelating agents carboxyethyl thiosuccinic acid (CETSA) and carboxyethyl thiosuccinic acid synthesized by the addition of 3-mercaptopropionic acid with maleic acid and maleic anhydride have the characteristics of acidity and strong chelating ability, and are suitable for cleaning and descaling in processes such as metal processing and oil field exploitation. Using 3-mercaptopropionic acid self-assembled monolayer as a template, it can induce the nucleation and growth of crystals such as calcium oxalate and calcium carbonate to generate a two-dimensional self-assembled monolayer showing unique structure and surface properties. The esterification product of 3-mercaptopropionic acid and pentaerythritol, pentaerythritol tetrakis (3-mercaptocarboxylic acid) ester (PETMP), can be used to synthesize high refractive index polymers. This polymer has a high refractive index, is light in weight, easy to process, and low in cost. It can replace glass, such as resin lenses and other fields. 3-Mercaptopropionic acid is used in the field of concrete water reducers in the largest amount. In the process of synthesizing polycarboxylic acid water-reducing agent, 3-mercaptopropionic acid can be used as a chain transfer agent to regulate the molecular weight of polycarboxylic acid and improve the water reduction rate and slump retention performance of concrete.

[0003] The method for synthesizing 3-mercaptopropionic acid is divided into two directions: homogeneous and heterogeneous. In homogeneous reactions, water is often used as a solvent, and NaHS and Na2S are used as thiol reagents to react with acrylic acid or acrylonitrile under strong alkaline conditions. The product of the reaction with acrylic acid is the sodium salt form of 3-mercaptopropionic acid, which needs to be acidified and then extracted to obtain 3-mercaptopropionic acid. The product of the reaction with acrylonitrile is the sodium salt form of 3-mercaptopropionic acid, which needs to be hydrolyzed, then acidified and extracted to obtain 3-mercaptopropionic acid. A large amount of inorganic acid and inorganic base need to be used in the whole process, thus generating a large amount of high-salt wastewater, and a large amount of organic solvent is also required in the extraction process.

[0004] Solid-phase catalysis mostly uses alkaline ion exchange resins as catalysts, such as Amberlyst A21, Amberlyst A26, modified cycloamine guanidine resins, etc. These anion exchange resins show good activity and good selectivity for 3-mercaptopropionic acid in the process of catalyzing the reaction of acrylic acid and hydrogen sulfide. However, the prominent disadvantage of ion exchange resins is that the resin swells significantly in the solvent, is easy to break, and is not easy to regenerate after deactivation. Some studies have used homemade MgO with high mechanical strength as a catalyst to catalyze the addition of acrylic acid and hydrogen sulfide. The acrylic acid conversion rate is above 98%, but the selectivity of 3-mercaptopropionic acid is about 36%. In the above methods, inorganic bases, MgO, and anion exchange resins are all alkaline catalysts, and there are no reports on processes using acidic catalysts. Summary of the invention

[0005] In order to solve the problems of low selectivity and difficulty in regeneration of 3-mercaptopropionic acid prepared by existing alkaline catalysts, the present invention provides a method for synthesizing 3-mercaptopropionic acid by catalyzing acrylic acid and hydrogen sulfide using an acidic molecular sieve.

[0006] The technical solution of the present invention:

[0007] A method for synthesizing 3-mercaptopropionic acid by using acrylic acid and hydrogen sulfide catalyzed by an acidic molecular sieve comprises the following steps:

[0008] Step 1: Pretreatment of molecular sieve catalyst: Mix molecular sieve, ammonium nitrate, concentrated nitric acid and water in a certain mass volume ratio, stir at 40-100°C for 5 hours, filter and collect solids, dry and calcine at 400°C for 4-12 hours;

[0009] Step 2: Repeat the molecular sieve catalyst pretreatment process described in step 1 three times to obtain the desired acidic molecular sieve catalyst;

[0010] Step 3: The acidic molecular sieve catalyst obtained in step 2, acrylic acid and an organic solvent are mixed in a certain mass volume ratio, hydrogen sulfide is introduced to a certain pressure, heated to a reaction temperature, and reacted for a certain time to obtain 3-mercaptopropionic acid.

[0011] Furthermore, the molecular sieve in step 1 is HY molecular sieve, HZSM5 molecular sieve, HBETA molecular sieve, MCM-41 molecular sieve or SBA-15 molecular sieve.

[0012] Furthermore, in step 1, the mass volume ratio of the molecular sieve, ammonium nitrate, concentrated nitric acid and water is 10g:2-10g:1ml:100g, and the concentration of the concentrated nitric acid is 68%.

[0013] Furthermore, the mass volume ratio of the acidic molecular sieve catalyst, acrylic acid and organic solvent in step 3 is 0.1-2 g:10 mL:50 mL.

[0014] Furthermore, the organic solvent in step three is a protic solvent and an aprotic solvent.

[0015] Furthermore, the protic solvent is an alcohol solvent or an amine solvent; the aprotic solvent is an ether solvent, an amide solvent, a ketone solvent, a nitrile solvent, pyridine or dimethyl sulfoxide.

[0016] Furthermore, the alcohol solvent is methanol, ethanol, propanol, isopropanol or butanol; the amine solvent is ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, pyrrolidine, N-alkylpyrrolidine, piperidine, N-alkylpiperidine, piperazine, N-alkylpiperazine or morpholine; the ether solvent is diethyl ether, methyl tert-butyl ether, 1,4-dioxane, ethylene glycol monomethyl ether or ethylene glycol dimethyl ether; the amide solvent is N,N-dimethylformamide, N,N-dimethylacetamide, N,N'-diethylformamide or N-methylpyrrolidone; the ketone solvent is acetone, butanone or cyclohexanone; the nitrile solvent is acetonitrile or propionitrile.

[0017] Furthermore, in step 3, the reaction temperature is 30-120° C., the pressure of hydrogen sulfide is 0.1-5 MPa, and the reaction time is 2-4 h.

[0018] Furthermore, the reaction temperature in step 3 is 40-100° C., and the pressure of hydrogen sulfide is 0.2-4 MPa.

[0019] Furthermore, the reaction temperature in step 3 is 50-90° C., and the pressure of hydrogen sulfide is 0.5-2.5 MPa.

[0020] Beneficial effects of the present invention:

[0021] The present invention uses an acidic molecular sieve, which has the characteristics of high catalytic activity, high selectivity, high mechanical strength and regeneration, catalyzes the addition of acrylic acid and hydrogen sulfide, and synthesizes 3-mercaptopropionic acid in one step. The conversion rate of 3-mercaptopropionic acid of 3-mercaptopropionic acid is higher than 90%, and the selectivity is higher than 85%. It has the characteristics of simple catalytic synthesis method and mild conditions. The molecular sieve can be a powdered molecular sieve or a molded molecular sieve. The molded molecular sieve can be applied to trickle bed reaction, and can also be applied to various reaction forms such as fluidized bed and reactor to realize synthesis reaction. The molded molecular sieve has high hardness and will not cause swelling and crushing of ion exchange resin in solvent. At the same time, the molecular sieve has good temperature resistance, and the failed catalyst can be regenerated by high-temperature roasting to achieve the purpose of repeated use. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described below in conjunction with the embodiments, but it is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention shall be included in the protection scope of the present invention. The process equipment or devices not specifically noted in the following embodiments are all conventional equipment or devices in the art. If not specifically specified, the raw materials used in the embodiments of the present invention can be obtained commercially; if not specifically specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.

[0023] Example 1

[0024] This embodiment provides a method for synthesizing 3-mercaptopropionic acid by using acrylic acid and hydrogen sulfide catalyzed by an acidic molecular sieve, comprising the following steps:

[0025] Step 1: Pretreatment of molecular sieve catalyst: Mix 10 g HY molecular sieve, 5 g ammonium nitrate, 1 mL 60% concentrated nitric acid solution and 100 g water, stir at 80°C for 5 h, filter and collect the solid, dry at 80°C and calcine at 400°C for 10 h;

[0026] Step 2: Repeat the molecular sieve catalyst pretreatment process described in step 1 three times to obtain the desired acidic molecular sieve catalyst;

[0027] Step 3: Add 0.2 g of the acidic HY molecular sieve catalyst obtained in step 2, 10 mL of acrylic acid and 50 mL of N,N-dimethylformamide (DMF) into an autoclave, introduce hydrogen sulfide to 0.70 MPa, heat to 60°C, react for 4 hours, and analyze by gas chromatography.

[0028] In this example, the acrylic acid conversion rate is 94.2%, and the 3-mercaptopropionic acid selectivity is 92.1%.

[0029] Example 2

[0030] This embodiment provides a method for synthesizing 3-mercaptopropionic acid by using acrylic acid and hydrogen sulfide catalyzed by an acidic molecular sieve, comprising the following steps:

[0031] Step 1: Pretreatment of molecular sieve catalyst: 10 g HBETA molecular sieve, 5 g ammonium nitrate, 1 mL 60% concentrated nitric acid solution and 100 g water were mixed, stirred at 80°C for 5 h, filtered to collect the solid, dried at 80°C and calcined at 400°C for 10 h;

[0032] Step 2: Repeat the molecular sieve catalyst pretreatment process described in step 1 three times to obtain the desired acidic molecular sieve catalyst;

[0033] Step 3: Add 2 g of the acidic HBETA molecular sieve obtained in step 2, 10 mL of acrylic acid and 50 mL of N,N-dimethylformamide (DMF) into an autoclave, introduce hydrogen sulfide to 0.70 MPa, heat to 60°C, react for 2 hours, and analyze by gas chromatography.

[0034] In this example, the acrylic acid conversion rate is 83.8%, and the 3-mercaptopropionic acid selectivity is 90.9%.

[0035] Example 3

[0036] This embodiment provides a method for synthesizing 3-mercaptopropionic acid by using acrylic acid and hydrogen sulfide catalyzed by an acidic molecular sieve, comprising the following steps:

[0037] Step 1: Pretreatment of molecular sieve catalyst: 10 g HZSM-5 molecular sieve, 5 g ammonium nitrate, 1 mL 60% concentrated nitric acid solution and 100 g water were mixed, stirred at 80°C for 5 h, filtered to collect the solid, dried at 80°C, and calcined at 400°C for 10 h;

[0038] Step 2: Repeat the molecular sieve catalyst pretreatment process described in step 1 three times to obtain the desired acidic molecular sieve catalyst;

[0039] Step 3: Add 0.2 g of the acidic HZSM-5 molecular sieve obtained in step 2, 10 mL of acrylic acid and 50 mL of N,N-dimethylformamide (DMF) into an autoclave, introduce hydrogen sulfide to 0.70 MPa, heat to 60°C, react for 2 hours, and analyze by gas chromatography.

[0040] In this example, the acrylic acid conversion rate is 95.4%, and the 3-mercaptopropionic acid selectivity is 87.3%.

[0041] Example 4

[0042] This embodiment provides a method for synthesizing 3-mercaptopropionic acid by using acrylic acid and hydrogen sulfide catalyzed by an acidic molecular sieve, comprising the following steps:

[0043] Step 1: Pretreatment of molecular sieve catalyst: 10 g of MCM-41 molecular sieve, 5 g of ammonium nitrate, 1 mL of 60% concentrated nitric acid solution and 100 g of water were mixed, stirred at 80° C. for 5 h, and then the solid was collected by filtration, dried at 80° C., and then calcined at 400° C. for 10 h;

[0044] Step 2: Repeat the molecular sieve catalyst pretreatment process described in step 1 three times to obtain the desired acidic molecular sieve catalyst;

[0045] Step 3: Add 0.2 g of the acidic MCM-41 molecular sieve obtained in step 2, 10 mL of acrylic acid and 50 mL of N,N-dimethylformamide (DMF) into an autoclave, introduce hydrogen sulfide to 0.70 MPa, heat to 60°C, react for 2 hours, and analyze by gas chromatography.

[0046] In this example, the acrylic acid conversion rate is 94.2%, and the 3-mercaptopropionic acid selectivity is 88.1%.

Claims

1. A method for synthesizing 3-mercaptopropionic acid by using acrylic acid and hydrogen sulfide catalyzed by an acidic molecular sieve, characterized in that: The steps include: Step 1: Pretreatment of molecular sieve catalyst: Mix molecular sieve, ammonium nitrate, concentrated nitric acid and water in a certain mass volume ratio, stir at 40-100°C for 5 hours, filter and collect solids, dry and calcine at 400°C for 4-12 hours; Step 2: Repeat the molecular sieve catalyst pretreatment process described in step 1 three times to obtain the desired acidic molecular sieve catalyst; Step 3: The acidic molecular sieve catalyst obtained in step 2, acrylic acid and an organic solvent are mixed in a certain mass volume ratio, hydrogen sulfide is introduced to a certain pressure, heated to a reaction temperature, and reacted for a certain time to obtain 3-mercaptopropionic acid.

2. The method for synthesizing 3-mercaptopropionic acid by using an acidic molecular sieve to catalyze acrylic acid and hydrogen sulfide according to claim 1, characterized in that: The molecular sieve in step 1 is HY molecular sieve, HZSM5 molecular sieve, HBETA molecular sieve, MCM-41 molecular sieve or SBA-15 molecular sieve.

3. A method for synthesizing 3-mercaptopropionic acid by using an acidic molecular sieve to catalyze acrylic acid and hydrogen sulfide according to claim 1 or 2, characterized in that: In step 1, the mass volume ratio of the molecular sieve, ammonium nitrate, concentrated nitric acid and water is 10g:2-10g:1ml:100g, and the concentration of the concentrated nitric acid is 68%.

4. The method for synthesizing 3-mercaptopropionic acid by using an acidic molecular sieve to catalyze acrylic acid and hydrogen sulfide according to claim 3, characterized in that: In step 3, the mass volume ratio of the acidic molecular sieve catalyst, acrylic acid and organic solvent is 0.1-2 g:10 mL:50 mL.

5. The method for synthesizing 3-mercaptopropionic acid by using an acidic molecular sieve to catalyze acrylic acid and hydrogen sulfide according to claim 4, characterized in that: The organic solvent in step 3 is a protic solvent or an aprotic solvent.

6. The method for synthesizing 3-mercaptopropionic acid by using an acidic molecular sieve to catalyze acrylic acid and hydrogen sulfide according to claim 5, characterized in that: The protic solvent is an alcohol solvent or an amine solvent; the aprotic solvent is an ether solvent, an amide solvent, a ketone solvent, a nitrile solvent, pyridine or dimethyl sulfoxide.

7. The method for synthesizing 3-mercaptopropionic acid by using an acidic molecular sieve to catalyze acrylic acid and hydrogen sulfide according to claim 6, characterized in that: The alcohol solvent is methanol, ethanol, propanol, isopropanol or butanol; the amine solvent is ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, pyrrolidine, N-alkylpyrrolidine, piperidine, N-alkylpiperidine, piperazine, N-alkylpiperazine or morpholine; the ether solvent is diethyl ether, methyl tert-butyl ether, 1,4-dioxane, ethylene glycol monomethyl ether or ethylene glycol dimethyl ether; the amide solvent is N,N-dimethylformamide, N,N-dimethylacetamide, N,N'-diethylformamide or N-methylpyrrolidone; the ketone solvent is acetone, butanone or cyclohexanone; the nitrile solvent is acetonitrile or propionitrile.

8. The method for synthesizing 3-mercaptopropionic acid by using acrylic acid and hydrogen sulfide catalyzed by an acidic molecular sieve according to claim 7, characterized in that: In step 3, the reaction temperature is 30-120° C., the pressure of hydrogen sulfide is 0.1-5 MPa, and the reaction time is 2-4 h.

9. The method for synthesizing 3-mercaptopropionic acid by using acrylic acid and hydrogen sulfide catalyzed by an acidic molecular sieve according to claim 8, characterized in that: In step 3, the reaction temperature is 40-100° C., and the pressure of hydrogen sulfide is 0.2-4 MPa.

10. The method for synthesizing 3-mercaptopropionic acid by using acrylic acid and hydrogen sulfide catalyzed by an acidic molecular sieve according to claim 9, characterized in that: In step 3, the reaction temperature is 50-90° C., and the pressure of hydrogen sulfide is 0.5-2.5 MPa.