EP-4741377-A1 - METHOD FOR PRODUCING AROMATIC NITRILE COMPOUND AND METHOD FOR PRODUCING CARBONIC ACID ESTER

Abstract

A method for producing an aromatic nitrile compound is provided by which the aromatic nitrile compound can be selectively obtained in high yield in a shortened reaction time using an aromatic amide compound and which can inhibit the formation of by-products. The above-mentioned problem was solved by the following method for producing an aromatic nitrile compound. The method for producing an aromatic nitrile compound includes a dehydration reaction in which an aromatic amide compound is dehydrated. The dehydration reaction includes a contact step in which the aromatic amide compound and a diluent are brought into contact with a catalyst in a gas phase. In the contact step, the temperature at which the aromatic amide compound and the diluent are brought into contact with the catalyst is 300°C or higher.

Inventors

• UMEZU Ryotaro
• IMADA Shin-ichiro
• SHINKAI YOUSUKE
• HARADA HIDEFUMI
• ISOBE TAKEHIKO

Assignees

• MITSUBISHI GAS CHEMICAL COMPANY, INC.

Dates

Publication Date

20260513

Application Date

20240703

Claims (18)

1. A method for producing an aromatic nitrile compound, comprising a dehydration reaction for dehydrating an aromatic amide compound, wherein the dehydration reaction comprises a contact step in which the aromatic amide compound and a diluent are brought into contact with a catalyst in a gas phase, and the temperature at which the aromatic amide compound and the diluent are brought into contact with the catalyst in the contact step is 300°C or higher.
2. The method for producing an aromatic nitrile compound according to claim 1, wherein the diluent comprises at least either a solvent or an inert gas.
3. The method for producing an aromatic nitrile compound according to claim 2, wherein the solvent comprises at least an aromatic compound.
4. The method for producing an aromatic nitrile compound according to claim 3, wherein the aromatic compound is represented by the following formula (1): in formula (1), R 1 is each independently selected from an optionally substituted C1-C10 alkyl group, an optionally substituted C1-C10 alkoxy group, an optionally substituted C6-C30 aryl group, and an optionally substituted C6-C30 aryloxy group, and a is an integer from 1 to 6.
5. The method for producing an aromatic nitrile compound according to claim 3, wherein the aromatic compound has one or two aromatic rings and one or more selected from an alkyl group, an alkoxy group, and an aryloxy group.
6. The method for producing an aromatic nitrile compound according to claim 3, wherein the aromatic compound has an autoignition temperature of 300°C or higher.
7. The method for producing an aromatic nitrile compound according to claim 3, wherein the aromatic compound comprises at least one of 1,3,5-trimethylbenzene, p-cymene, phenyl ether, and anisole.
8. The method for producing an aromatic nitrile compound according to claim 1, wherein the pressure of a reaction system in the contact step is 101.3 kPa or less.
9. The method for producing an aromatic nitrile compound according to claim 1, wherein the aromatic amide compound comprises at least a heteroaryl amide compound, and the aromatic nitrile compound comprises at least a heteroaryl nitrile compound.
10. The method for producing an aromatic nitrile compound according to claim 9, wherein the heteroaryl amide compound comprises 2-picolinamide, and the heteroaryl nitrile compound comprises 2-cyanopyridine.
11. The method for producing an aromatic nitrile compound according to claim 1, wherein an inert gas in a vaporized state is used in the contact step.
12. The method for producing an aromatic nitrile compound according to claim 11, wherein the inert gas comprises at least nitrogen gas.
13. The method for producing an aromatic nitrile compound according to claim 1, wherein the catalyst comprises an alkali metal.
14. The method for producing an aromatic nitrile compound according to claim 1, wherein the solvent is compatible with the aromatic amide compound.
15. The method for producing an aromatic nitrile compound according to claim 1, wherein the contact time of the aromatic amide compound with the catalyst in the gas phase is 0.001 seconds or more but less than 10 seconds.
16. A method for producing a carbonate ester, comprising: a first reaction step comprising a carbonate ester-generating reaction in which an alcohol and carbon dioxide are reacted with each other in the presence of an aromatic nitrile compound to generate a carbonate ester and water, and a hydration reaction in which the aromatic nitrile compound is hydrated with the generated water to form an aromatic amide compound; and a second reaction step in which the aromatic amide compound is separated from the reaction system of the first reaction step, and then an aromatic nitrile compound is regenerated from the aromatic amide compound by a dehydration reaction for dehydrating the aromatic amide compound, the dehydration reaction involving the contact step according to any one of claims 1-15, wherein at least a portion of the aromatic nitrile compound regenerated in the second reaction step is used in the first reaction step.
17. The method for producing a carbonate ester according to claim 16, wherein a catalyst comprising cerium oxide is used in the carbonate ester-generating reaction.
18. The method for producing a carbonate ester according to claim 16, wherein the alcohol comprises a C1-C6 alcohol.

Description

TECHNICAL FIELD The present invention relates to a method for producing an aromatic nitrile compound, comprising a step of dehydrating an aromatic amide compound in a gas phase, and to a method for producing a carbonate ester. BACKGROUND ART A carbonate ester is a generic term for a compound in which one or two of the two hydrogen atoms in carbonic acid CO(OH)2 are replaced by an alkyl or aryl group, and which has the structure RO-C(=O)-OR' (where R and R' each represent a saturated hydrocarbon group or an unsaturated hydrocarbon group). Carbonate esters are very useful compounds that can be used as additives such as a gasoline additive to improve the octane number, as a diesel fuel additive to reduce particles in exhaust gas, and also as an alkylation agent, a carbonylation agent, a solvent or the like used to synthesize a resin or an organic compound such as a polycarbonate, a urethane, a pharmaceutical, or an agrochemical, or as an electrolyte for lithium ion batteries, a feedstock for a lubricant, or a feedstock for an oxygen absorber to prevent rust on boiler pipes. Conventionally known methods for producing a carbonate ester, for example, include those involving a step in which water generated as a by-product by the reaction between an alcohol and carbon dioxide is reacted with a nitrile compound (Patent literature 1, 2, etc.). These carbonate ester production methods include a step of dehydrating an amide compound formed from water and the nitrile compound to regenerate the nitrile compound. Such conventional carbonate ester production methods do not always allow for the selective regeneration of the nitrile compound in a high percent yield in a short period of time, and thus it is not easy to produce the target compound, i.e., a carbonate ester, in an efficient manner. PRIOR ART DOCUMENTS PATENT DOCUMENTS Patent literature 1: WO2015/099053Patent literature 2: WO2020/022416 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION The main objective of the present invention is to provide a method for producing an aromatic nitrile compound using an aromatic amide compound, according to which method an aromatic nitrile compound can be selectively obtained in a high percent yield while shortening the reaction time and also suppressing the generation of by-products. It is also an objective of the present invention to realize a method for effectively producing a carbonate ester by applying such a method for producing an aromatic nitrile compound. MEANS FOR SOLVING THE PROBLEMS The present inventors have examined methods for producing an aromatic nitrile compound which involve dehydrating an aromatic amide compound, and have found that bringing an aromatic amide compound and a diluent into contact with a catalyst in a gas phase at a high temperature significantly improves the reaction rate, shortens the reaction time, and suppresses the generation of by-products, enabling the target compound to be obtained in a high percent yield. According to the present invention, the regeneration rate of the dehydration reaction that converts an aromatic amide compound into an aromatic nitrile compound can be improved. Furthermore, a method of the present invention for producing a carbonate ester using carbon dioxide and an alcohol, which incorporates such a dehydration reaction step, has been confirmed to have excellent effects, including efficient production of a carbonate ester. The present invention, for example, includes the following. [1] A method for producing an aromatic nitrile compound, comprising a dehydration reaction for dehydrating an aromatic amide compound, wherein the dehydration reaction comprises a contact step in which the aromatic amide compound and a diluent are brought into contact with a catalyst in a gas phase, and the temperature at which the aromatic amide compound and the diluent are brought into contact with the catalyst in the contact step is 300°C or higher.[2] The method for producing an aromatic nitrile compound according to [1] above, wherein the diluent comprises at least either a solvent or an inert gas.[3] The method for producing an aromatic nitrile compound according to [2] above, wherein the solvent comprises at least an aromatic compound.[4] The method for producing an aromatic nitrile compound according to [3] above, wherein the aromatic compound is represented by the following formula (1): in formula (1), R1 is each independently selected from an optionally substituted C1-C10 alkyl group, an optionally substituted C1-C10 alkoxy group, an optionally substituted C6-C30 aryl group, and an optionally substituted C6-C30 aryloxy group, anda is an integer from 1 to 6.[5] The method for producing an aromatic nitrile compound according to either one of [3] or [4] above, e.g., [3] above, wherein the aromatic compound has one or two aromatic rings and one or more selected from an alkyl group, an alkoxy group, and an aryloxy group.[6] The method for producing an aromatic nitrile com