A method for synthesizing dimethyl fumarate and dimethyl maleate by dicarbonylation of acetylene

Abstract

The present invention provides a method for synthesizing dimethyl fumarate and dimethyl maleate by dicarbonylation of acetylene, which uses acetylene, carbon monoxide and methyl nitrite as raw materials, and reacts them under the action of a supported palladium catalyst at a temperature of 60-200°C. o C. Under conditions of pressure of 0.1 to 6 MPa, acetylene is subjected to a double carbonylation reaction for 0.5 to 48 hours to obtain dimethyl fumarate and dimethyl maleate compounds. The present invention replaces methanol with methyl nitrite and employs a supported palladium catalyst, eliminating the need for any auxiliary agents and the direct use of O2. This avoids the problems of explosion limits, the use of corrosive auxiliary agents, and the separation and recycling of catalysts in the current double carbonylation of acetylene, overcoming the technical pain points of the prior art. Furthermore, the reaction has the advantages of high atomic utilization, mild reaction conditions, and high product yields. The byproduct, NO, can be recycled, making it suitable for industrial production and promising broad application prospects.

Description

Technical Field

[0001] The present invention relates to a method for preparing dimethyl fumarate and dimethyl maleate by double carbonylation of acetylene, and in particular to a method for preparing dimethyl fumarate and dimethyl maleate by double carbonylation of acetylene using methyl nitrite as a raw material under the action of a supported catalyst, belonging to the technical field of synthetic chemistry. Background Art

[0002] C4 oxygenated compounds, such as 1,4-butanediol, 1,4-butanediol, dimethyl succinate, dimethyl fumarate, and dimethyl maleate, are widely used in the fields of medicine, fine chemicals, and biodegradable polymers. For example, dimethyl fumarate is only used in enteric-coated capsules for the treatment of relapsing multiple sclerosis (MS); dimethyl succinate can be obtained through transesterification to obtain a C4 oxygenated compound with a molecular weight of 5.95×10 5 The biodegradable polymer polybutylene succinate (PBS) is currently being produced through the butadiene method, maleic anhydride method, 1,4-dichlorobutene method, acetylene aldehyde method, acetylene carbonylation method, and the conversion of these compounds through hydrogenation, hydrolysis, and esterification. The acetylene carbonylation method, which produces dimethyl fumarate and dimethyl maleate, uses methanol, acetylene, and CO as raw materials through a catalytic conversion process in the presence of catalysts, additives, and oxidants. This process has been discovered for more than 50 years, but as a useful reaction, there has been no industrial report yet (see: Progress in Chemistry, 2021, 33(2): 243-253; Angew. Chem. Int. Ed. 2023, 62, e202307570; ACS Catal. 2021, 11, 9242-9251; J. Catal. 2022, 413,762). Further analysis shows that the following key issues limit the industrial application of this process:

[0003] (1) Explosion limits: The explosion limits of CO, acetylene, and air are 12.5% ​​to 80% for a mixture of CO and air; the explosion limit of acetylene in air is 2.3% to 72.3%. In the methods disclosed in Chinese patents CN202210143998 and CN202210086473, under the disclosed reaction conditions, the ratio of the mixed gas of air, CO, and acetylene introduced is: 2.5 MPa: 2.6 MPa: 0.4 MPa or 3.0 MPa: 2.0 MPa: 0.5 MPa; similarly, in the method disclosed in Chinese patent CN202210143998, under the disclosed reaction conditions, the total pressure of the mixed gas of air, CO, and acetylene introduced is 4 MPa, including 1.8 MPa of CO and 11 mmol of acetylene. Based on the above-mentioned explosion limit indicators of acetylene and CO in air, the experimental conditions disclosed in the above patents are all within the explosion limits of CO and acetylene / air. Therefore, any slight improper operation will cause the risk of explosion, which is not conducive to safe production and is also the biggest obstacle to its industrial application.

[0004] (2) Corrosive additives: Chinese patents CN202210143998, CN202210143998, CN202210086473, and the latest literature (Angew. Chem. Int. Ed. 2023, 62, e202307570; ACS Catal. 2021, 11, 9242-9251; J. Catal. 2022, 413, 762) all report the need to add corrosive iodized salt additives. In the oxidative carbonylation reaction in which most of the iodized salt in the root participates, the iodine additive will produce corrosive hydroiodic acid during the reaction, which will inevitably cause corrosion to the equipment and loss of active metals. In the method disclosed in Chinese patent CN201910860411, although no oxidant is used in the disclosed reaction conditions, a homogeneous catalyst and a corrosive halide salt are used and a strong acid needs to be added additionally, which is not conducive to the separation cycle of the precious metal catalyst and is easy to corrode the reaction equipment, and is not conducive to industrial production. Therefore, from the perspective of existing technical means, the industrial application of acetylene dicarbonylation has certain technical difficulties. Seeking other new catalytic processes for acetylene dicarbonylation to circumvent pain points such as explosion limits, corrosive additives, and product separation is the only way to realize the application of acetylene dicarbonylation. Summary of the Invention

[0005] The main purpose of the present invention is to provide a method for synthesizing dimethyl fumarate and dimethyl maleate by acetylene dicarbonylation using methyl nitrite as a raw material, so as to overcome the shortcomings of the existing acetylene dicarbonylation technology.

[0006] The method for synthesizing dimethyl fumarate and dimethyl maleate by dicarbonylation of acetylene is as follows: acetylene, carbon monoxide and methyl nitrite are used as raw materials, and the reaction mixture is heated at a temperature of 60 to 200°C under the action of a supported palladium catalyst. o C. Under a pressure of 0.1-10 MPa, acetylene is subjected to a double carbonylation reaction for 0.5-48 hours to obtain dimethyl fumarate and dimethyl maleate compounds. The reaction formula is as follows:

[0007]

[0008] The molar ratio of the raw materials acetylene, carbon monoxide and methyl nitrite is 1:2:2~1:100:6.

[0009] In the supported palladium catalyst, the carrier is one or more of activated carbon, porous polymer, aluminum oxide, titanium oxide, cerium oxide, magnesium oxide, and molecular sieve, and the loading amount of palladium is 0.05~10wt.%. The supported gold catalyst is a precursor of palladium using palladium nitrate, palladium chloride, palladium bromide, palladium acetate, palladium trifluoroacetate, palladium acetylacetonate, sodium chloropalladate, potassium chloropalladate, etc., and is prepared by impregnation, precipitation, atomic deposition, liquid phase reduction or vapor phase reduction. The molar ratio of acetylene to the active metal in the supported catalyst is 100:1~10000:1.

[0010] The acetylene dicarbonylation reaction can be carried out in the absence of a solvent or in a reaction solvent, wherein the reaction solvent includes one or more of tetrahydrofuran, ethyl acetate, methanol, acetonitrile, dioxane, toluene, and cyclohexane.

[0011] The reaction of the present invention is carried out in a batch tank reactor or in a continuous tubular reactor.

[0012] In summary, the present invention has the following advantages over the prior art:

[0013] 1. The present invention circumvents the difficulties of traditional technologies by replacing methanol with methyl nitrite and using a supported palladium catalyst. It does not require any auxiliary agents and does not directly use O2. It avoids the problems of explosion limits, the use of corrosive auxiliary agents, and catalyst separation and recycling in the current acetylene double carbonylation process, and overcomes the technical pain points of the existing technology.

[0014] 2. The reaction atom utilization rate of the present invention is high, and the by-product is NO which can be recycled;

[0015] 3. The present invention has the advantages of mild reaction conditions and high product yield, is suitable for industrial production, and has broad application prospects. It has good development prospects based on current C4 oxygen-containing compounds such as 1,4-butanediol, 1,4-butanediol, dimethyl succinate, dimethyl fumarate, and dimethyl maleate. DETAILED DESCRIPTION

[0016] The method for preparing dimethyl fumarate and dimethyl maleate by dicarbonylation of acetylene of the present invention is further described in detail below with reference to specific examples.

[0017] Example 1

[0018] 2 g of activated carbon powder was added to 8 mL of 0.0001 mol / L palladium nitrate aqueous solution, immersed for 24 h, dried, calcined at 500 °C for 3 h in an inert atmosphere, and then reduced at 300 °C for 2 h in hydrogen to obtain a Pd / C catalyst, which was labeled as catalyst 1.

[0019] In a 50 mL reactor, catalyst 1 (10 mg), 5 mL of tetrahydrofuran, 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO were added. The reactor was heated to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0020] Example 2

[0021] Preparation of Pd / C catalyst: 2 g of activated carbon powder was added to 8 mL of 0.0001 mol / L palladium acetate in acetonitrile solution and soaked for 24 h. The mixture was then dried and calcined at 500 °C for 3 h in an inert atmosphere. The mixture was then reduced in hydrogen at 300 °C for 2 h to obtain a Pd / C catalyst, designated as catalyst 2.

[0022] In a 50 mL reactor, catalyst 2 (10 mg), 5 mL of tetrahydrofuran, 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO were added. The reactor was heated to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0023] Example 3

[0024] Preparation of Pd / C catalyst: 2 g of activated carbon powder was added to 8 mL of 0.0001 mol / L acetone solution and immersed for 24 h. The mixture was then dried and calcined at 500 °C for 3 h in an inert atmosphere. The mixture was then reduced in hydrogen at 300 °C for 2 h to obtain a Pd / C catalyst, designated as catalyst 3.

[0025] In a 50 mL reactor, catalyst 3 (10 mg), 5 mL of tetrahydrofuran, 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO were added. The reactor was heated to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0026] Example 4

[0027] Preparation of Pd / C catalyst: 2 g of activated carbon powder was added to 8 mL of 0.0001 mol / L potassium chloropalladate aqueous solution and immersed for 24 h. The mixture was then dried and calcined at 500 °C for 3 h in an inert atmosphere. The mixture was then reduced at 300 °C for 2 h in hydrogen to obtain a Pd / C catalyst, designated as catalyst 7.

[0028] In a 50 mL reactor, catalyst 7 (10 mg), 5 mL of tetrahydrofuran, 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO were added. The reactor was heated to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0029] Example 5

[0030] Preparation of Pd / Al2O3 catalyst: 2 g of Al2O3 powder was added to 8 mL of 0.0001 mol / L palladium nitrate aqueous solution and immersed for 24 h. The mixture was then dried and calcined at 500°C in a muffle furnace for 3 h. The mixture was then reduced in hydrogen at 300°C for 2 h to obtain a Pd / Al2O3 catalyst, designated as catalyst 4.

[0031] In a 50 mL reactor, catalyst 4 (10 mg), 5 mL of tetrahydrofuran, 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO were added. The reactor was heated to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0032] Example 6

[0033] Preparation of Pd / TiO2 catalyst: 2 g of TiO2 powder was added to 8 mL of 0.0001 mol / L palladium nitrate aqueous solution and immersed for 24 h. The mixture was then dried and calcined at 500°C in a muffle furnace for 3 h. The mixture was then reduced in hydrogen at 300°C for 2 h to obtain a Pd / TiO2 catalyst, designated as catalyst 5.

[0034] In a 50 mL reactor, catalyst 5 (10 mg), 5 mL of tetrahydrofuran, 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO were added. The reactor was heated to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0035] Example 7

[0036] Preparation of Pd / CeO2 catalyst: 2 g of CeO2 powder was added to 8 mL of 0.0001 mol / L palladium acetate in acetonitrile solution and soaked for 24 h. The mixture was then dried and calcined at 500°C in a muffle furnace for 3 h. The mixture was then reduced in hydrogen at 300°C for 2 h to obtain a Pd / TiO2 catalyst, designated as catalyst 6.

[0037] In a 50 mL reactor, catalyst 6 (10 mg), 5 mL of tetrahydrofuran, 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO were added. The reactor was heated to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0038] Example 8

[0039] In a 50 mL reactor, catalyst 1 (10 mg), 5 mL of methanol, 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO were added. The reactor was heated to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0040] Example 9

[0041] In a 50 mL reactor, catalyst 1 (10 mg), 5 mL of ethyl acetate, 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO were added. The reactor was heated to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0042] Example 10

[0043] In a 50 mL reactor, add catalyst 1 (10 mg), 5 mL of dioxane, 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO. Heat the reactor to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0044] Example 11

[0045] In a 50 mL reactor, add catalyst 1 (10 mg), 5 mL of acetonitrile, 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO. Heat the reactor to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0046] Example 12

[0047] In a 50 mL reactor, catalyst 1 (10 mg), 5 mL of cyclohexane, 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO were added. The reactor was heated to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0048] Example 13

[0049] In a 50 mL reactor, catalyst 1 (10 mg), 5 mL of toluene, 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO were added. The reactor was heated to 130 oC, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0050] Example 14

[0051] In a 50 mL reactor, add catalyst 1 (10 mg), charge 3 mmol acetylene, 8 mmol methyl nitrite, 5 mL toluene, charge 2 MPa CO, and heat the reactor to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0052] Example 15

[0053] In a 50 mL reactor, catalyst 1 (10 mg) was added, along with 3 mmol of acetylene, 8 mmol of methyl nitrite, and 2 MPa of CO. The reactor was heated to 130 o C, and reacted for 12 h. After the reaction, 5 mL of tetrahydrofuran was added to dissolve the product. Samples were taken for analysis using GC with n-hexane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0054] Example 16

[0055] In a 50 mL reactor, catalyst 1 (10 mg) was added, 3 mmol of acetylene, 8 mmol of methyl nitrite, 5 mL of toluene were charged, 4 MPa of CO was charged, and the reactor was heated to 130 o C, and reacted for 12 h. After the reaction, samples were taken for testing using GC with dodecane as the internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0056] Examples 17-21

[0057] According to the reaction conditions in Examples 1 to 7, the catalyst after the reaction was recovered and the stability was investigated under the same reaction conditions. After the reaction, samples were taken for detection using dodecane as an internal standard. The detection method was a GC method using dodecane as an internal standard. The yields and selectivities of dimethyl fumarate and dimethyl maleate were calculated. The results are shown in Table 1.

[0058] It can be seen from the data in Table 1 that the method for preparing dimethyl fumarate and dimethyl maleate by dicarbonylation of acetylene and the catalyst thereof of the present invention have high reaction activity, good selectivity and good catalyst stability, and have broad application prospects.

[0059] In addition, the inventors of this case also conducted experiments with other raw materials and conditions listed in this specification, referring to the methods of Examples 1-21, and were able to achieve corresponding effects.

[0060]

Claims

1. A method for synthesizing dimethyl fumarate and dimethyl maleate by dicarbonylation of acetylene, characterized in that: This method uses acetylene, carbon monoxide and methyl nitrite as raw materials. Under the action of a supported palladium catalyst, acetylene is subjected to a double carbonylation reaction for 12 to 48 hours at a temperature of 130 to 200°C and a pressure of 0.1 to 6 MPa to obtain dimethyl fumarate and dimethyl maleate compounds.

2. The method for synthesizing dimethyl fumarate and dimethyl maleate by dicarbonylation of acetylene as claimed in claim 1, characterized in that: The molar ratio of the raw materials acetylene, carbon monoxide and methyl nitrite is 1:2:2~1:100:

6.

3. The method for synthesizing dimethyl fumarate and dimethyl maleate by dicarbonylation of acetylene as claimed in claim 1, characterized in that: In the supported palladium catalyst, the carrier is one or more of activated carbon, porous polymer, aluminum oxide, titanium oxide, cerium oxide, magnesium oxide, and molecular sieve, and the loading amount of palladium is 0.05-10 wt.%.

4. The method for synthesizing dimethyl fumarate and dimethyl maleate by dicarbonylation of acetylene as claimed in claim 1, characterized in that: The molar ratio of acetylene to the active metal in the supported catalyst is 100:1 to 10000:

1.

5. The method for synthesizing dimethyl fumarate and dimethyl maleate by dicarbonylation of acetylene as claimed in claim 1, characterized in that: The acetylene dicarbonylation reaction is carried out under solvent conditions, and the reaction solvent is one or more of methanol, tetrahydrofuran, acetonitrile, dioxane, ethyl acetate, toluene, xylene, and cyclohexane.

6. The method for synthesizing dimethyl fumarate and dimethyl maleate by dicarbonylation of acetylene as claimed in claim 1, characterized in that: The acetylene dicarbonylation reaction is carried out in a batch reactor or a continuous tubular reactor.

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