A method for preparing urea compounds by catalytic activation of carbon dioxide with a thiolate-based ionic liquid

Abstract

The present application relates to the technical field of urea compound preparation, and particularly relates to a method for preparing urea compounds by activating carbon dioxide with mercaptide-based ionic liquid as a catalyst. The present application uses amine compounds as reaction substrates, uses CO2 as a carbonylation reagent, and uses mercaptide-based ionic liquid as a catalyst for reaction. Compared with the existing preparation method of urea compounds, the present application realizes efficient activation of CO2 by precisely regulating the structure of the anion and cation of the mercaptide-based ionic liquid, and overcomes the three major bottlenecks of low solubility in organic phase, difficult structure regulation and poor recyclability of traditional inorganic sulfides NaSH, Na2S or H2S in the synthesis of urea compounds by catalytic activation of CO2.

Description

Technical Field

[0001] This invention relates to the field of urea compound preparation technology, and more specifically, to a method for preparing urea compounds by catalytic activation of carbon dioxide using a thiolate-based ionic liquid. Background Technology

[0002] Currently, urea synthesis primarily uses CO as a traditional carbonylation reagent, which can be used directly or by converting it into highly reactive intermediates such as phosgene and dimethyl carbonate to synthesize urea compounds, offering high atom economy. However, this method has significant inherent drawbacks: First, CO itself is highly toxic, flammable, and explosive, and its storage, transportation, and use are accompanied by extremely high safety risks and costs, limiting its industrial application. Second, effective carbonylation reactions typically rely on expensive and complex noble metal catalysts (such as palladium and platinum) to activate stable carbon-oxygen triple bonds, significantly increasing process costs. Third, both upstream CO production (relying on incomplete combustion of fossil fuels or water-gas shift reactions) and downstream carbonylation processes involve high energy consumption and high pressure conditions, which are inconsistent with the development direction of green chemistry. Therefore, although this method is technically mature, it faces insurmountable bottlenecks in terms of safety, economy, and environmental friendliness.

[0003] Carbon dioxide (CO2), as a widely available, low-toxicity, non-flammable, and renewable C1 resource, exhibits great potential in green synthetic chemistry due to its unique physicochemical properties. From the perspective of green chemistry and atom economy, the CO2 molecule possesses a typical carbonyl structure, theoretically making it an ideal carbonylation reagent to replace traditionally used toxic and harmful raw materials such as phosgene and carbon monoxide in the synthesis of urea compounds. This conversion pathway not only helps to realize the resource utilization of CO2 and reduce greenhouse gas emissions but also provides a sustainable carbon source for the green synthesis of chemicals, which has significant scientific and strategic value for promoting the low-carbon transformation of the energy and chemical industries.

[0004] The core of synthesizing urea compounds using carbon dioxide as a carbonylation reagent lies in promoting the combination of amines with CO2 and the subsequent dehydration steps. CO2, as a thermodynamically stable and kinetically inert molecule, presents a significant challenge in green chemistry and carbon resource utilization due to its activation and efficient conversion. To overcome its reaction inertia, current research has developed non-metallic catalyst systems, such as nitrogen-heterocyclic carbenes and sterically hindered Lewis acid-base pairs, aiming to achieve CO2 activation under mild conditions through weak interactions with non-metallic sites such as boron, nitrogen, and phosphorus, and subsequently react with amines to synthesize urea compounds. Inspired by this, studies have utilized weakly based, strongly nucleophilic inorganic sulfides NaSH, Na2S, or H2S to activate CO2, establishing a new method for CO2 activation and conversion to urea compounds. While this method shows some catalytic potential, it still has significant limitations in practical applications: firstly, the solubility of inorganic sulfides in organic reaction systems is generally low, leading to limited mass transfer and decreased reaction efficiency; secondly, the active species HS... - The structure is difficult to control. These factors together limit the application potential of this type of method in large-scale, continuous industrial scenarios. Summary of the Invention

[0005] To address the aforementioned technical problems in existing methods for preparing urea compounds, this invention provides a method for preparing urea compounds by catalytic activation of carbon dioxide using thiolate-based ionic liquids.

[0006] This invention uses amine compounds as reaction substrates, CO2 as carbonylation reagents, and thiolate-based ionic liquids as catalysts for the reaction. Specifically, in a solvent, the thiolate-based ionic liquid catalyzes the reaction of CO2 with amine compounds to generate urea compounds.

[0007] One of the objectives of this invention is to provide a method for preparing urea compounds.

[0008] The method for preparing urea compounds includes: reacting CO2 with amine compounds in an inert solvent using a thiolate-based ionic liquid as a catalyst;

[0009] The amine compounds are selected from aliphatic diamine compounds, alicyclic diamine compounds, o-phenylenediamine compounds, and aliphatic primary amine compounds; The urea compounds are selected from 2-imidazolidine ketones, benzimidazolidine ketones, and linear benzyl symmetrical urea compounds; The anion of the thiolate-based ionic liquid is selected from [4-AT-BT]. - [4-MeO-BT] - [4-Me-BT] - [4-Br-BT] - [4-Tp]- [2-Tp] - [BnT] - At least one of them; The cation of the thioglycol-based ionic liquid is selected from [TBP]. + [TBA] + [TMA] + [TEA] + [Ch] + [DBUH] + At least one of them; The inert solvent is selected from at least one of NMP, DMF, EG, THF, DMSO, 1,4-dioxane, HMPA, CH2Cl2, CHCl3, CCl4, toluene, ethyl acetate, and supercritical CO2.

[0010] The chemical formula of the aliphatic diamine compound is: Wherein, R1, R2, R3, and R4 are independently selected from: H, C1-C6 alkyl, C1-C6 alkoxy, NH2, NO2, SO2CH3, and substituted or unsubstituted phenyl groups; the substituents of the phenyl group are selected from at least one of C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy, NH2, NO2, and SO2CH3, and the number of substituents is 1 to 4. The substitution position of the phenyl group can be arbitrary, and the substituents at any two or more positions can be the same or different.

[0011] The aliphatic diamine compounds may specifically be: ethylenediamine, N-methylethylenediamine, N-ethylethylenediamine, 1,2-propanediamine, 1,2-diamino-2-methylpropane, N,N-dimethylethylenediamine, N,N-diethylethylenediamine, N-phenylethylenediamine, N,N-diisopropylethylenediamine, 1,3-propanediamine, N-methyl-1,3-propanediamine, N,N-dimethyl-1,3-propanediamine, N-ethyl-1,3-propanediamine, dimethylpropanediamine, N-isopropyl-1,3-propanediamine, and 1,2-diphenylethylenediamine.

[0012] When the reaction substrate is an aliphatic diamine compound When the reaction produces urea compounds, they are 2-imidazolidine ketones. The aforementioned In this context, R1, R2, R3, and R4 are independently selected from: H, C1-C6 alkyl, C1-C6 alkoxy, NH2, NO2, SO2CH3, and substituted or unsubstituted phenyl groups; the substituents of the phenyl group are selected from at least one of C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy, NH2, NO2, and SO2CH3, and the number of substituents is 1 to 4. The substitution positions of the phenyl group can be arbitrary, and the substituents at any two or more positions can be the same or different.

[0013] The 2-imidazolidine ketone compounds R1, R2, R3, and R4 in the reaction are derived from aliphatic diamine compounds. R1, R2, R3, and R4 in the equation.

[0014] The chemical formula of the alicyclic diamine compound is: Among them, R a R b R c Independently selected from: H, C1-C6 alkyl groups, n=1~3. R c The substitution site can be any position on the alicyclic ring.

[0015] The alicyclic diamine compounds may specifically be: 1,2-cyclohexanediamine, N,N-dimethyl-1,2-cyclohexanediamine.

[0016] When the substrate is an alicyclic diamine, the resulting urea compound is a 2-imidazolidine ketone. The aforementioned In the middle, R a R b R c Independently selected from: H, C1-C6 alkyl groups, n=1~3. R c The substitution site can be any position on the alicyclic ring.

[0017] The 2-imidazolidine ketone compounds R in a R b R c From alicyclic diamine compounds as reaction substrates R in a R b R c . n and The n values ​​are equal.

[0018] The 2-imidazolidine ketone compounds may specifically be: 2-imidazolidine ketone, N-methyl-2-imidazolidine ketone, N-ethyl-2-imidazolidine ketone, 4-methyl-2-imidazolidine ketone, 4,4-dimethyl-2-imidazolidine ketone, 1,3-dimethyl-2-imidazolidine ketone, 1,3-diethyl-2-imidazolidine ketone, N-phenyl-2-imidazolidine ketone, 1,3-diisopropyl-2-imidazolidine ketone, tetrahydropyrimidine-2(1H)-one 1-Methyl-tetrahydropyrimidine-2(1H)-one, 1,3-dimethyltetrahydropyrimidine-2(1H)-one, 1-ethyltetrahydropyrimidine-2(1H)-one, 5,5-dimethyltetrahydropyrimidine-2(1H)-one, 1-isopropyltetrahydropyrimidine-2(1H)-one, 4,5-diphenyl-2-imidazolidineone, octahydro-2H-benzimidazole-2-one, 1,3-dimethyloctahydro-2H-benzimidazole-2-one.

[0019] The chemical formula of the o-phenylenediamine compound is: Wherein, R5 is selected from at least one of H, halogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl, COOR, and substituted or unsubstituted phenyl groups; R is selected from C1-C6 alkyl. The substitution position of R5 can be any position, and any two or more R5 positions can be the same or different. The substituents of the phenyl group are selected from at least one of C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy, NH2, NO2, and SO2CH3, and the number of substituents is 1 to 4; the substitution position of the phenyl group can be any position, and any two or more substituent positions can be the same or different.

[0020] The o-phenylenediamine compounds may specifically include: o-phenylenediamine, 6-methyl o-phenylenediamine, 5-methyl o-phenylenediamine, 5,6-dimethyl o-phenylenediamine, 5-tert-butyl o-phenylenediamine, naphth-2,3-diamine, 5-fluoro o-phenylenediamine, 5-chloro o-phenylenediamine, 5-bromo o-phenylenediamine, 4,5-dichloro o-phenylenediamine, 3,5-dichloro o-phenylenediamine, 4-bromo-5-methyl o-phenylenediamine, 5-bromo-3-methyl o-phenylenediamine, 3-bromo-4-fluoro o-phenylenediamine, 4-trifluoromethyl o-phenylenediamine, methyl 3,4-diaminobenzoate, 4-chloro-5-fluoro o-phenylenediamine, and 4-nitro o-phenylenediamine.

[0021] When the reaction substrate is an o-phenylenediamine compound When the reaction produces urea compounds, the compounds are benzimidazoles. The aforementioned In this context, R5 is selected from at least one of H, halogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl, COOR, and substituted or unsubstituted phenyl groups; R is selected from C1-C6 alkyl. The substitution position of R5 can be arbitrary, and any two or more R5 groups can be the same or different. The substituents of the phenyl group are selected from C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy, NH2, NO2, and SO2CH3, and the number of substituents is 1 to 4; the substitution position of the phenyl group can be arbitrary, and any two or more substituents can be the same or different.

[0022] The benzimidazole compounds R5 in the reaction comes from the o-phenylenediamine compound. R5 in the middle.

[0023] The benzimidazole ones may specifically include: benzimidazole-2-one, 6-methylbenzimidazole-2-one, 5-methylbenzimidazole-2-one, 5,6-dimethylbenzimidazole-2-one, 5-tert-butylbenzimidazole-2-one, naphthimazole-2-one, 5-fluorobenzimidazole-2-one, 5-chlorobenzimidazole-2-one, 5-bromobenzimidazole-2-one, and 4,5-dichlorobenzimidazole-2-one. 3,5-Dichlorobenzimidazole-2-one, 4-bromo-5-methylbenzimidazole-2-one, 5-bromo-3-methylbenzimidazole-2-one, 3-bromo-4-fluorobenzimidazole-2-one, 4-trifluoromethylbenzimidazole-2-one, methyl 2-oxo-2,3-dihydro-1H-benzimidazole-5-carboxylate, 4-chloro-5-fluorobenzimidazole-2-one, 4-nitro-benzimidazole-2-one.

[0024] The chemical formula of the aliphatic primary amine compound is: R6 is selected from H, substituted or unsubstituted C1-C. 12 The substituents are alkyl, substituted or unsubstituted C3-C8 cycloalkyl, substituted or unsubstituted phenyl, substituted or unsubstituted 5-12 membered heteroaryl, or substituted or unsubstituted 5-12 membered saturated or partially unsaturated heterocycles. The substituents of the alkyl, cycloalkyl, phenyl, heteroaryl, or heterocycle are independently selected from halogens, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy, OH, phenyl, and naphthyl groups, and the number of substituents is 1 to 2. The substituents can be substituted at any position on the alkyl, cycloalkyl, phenyl, heteroaryl, or heterocycle, and any two or more substituents can be the same or different.

[0025] The specific aliphatic primary amine compounds may be: benzylamine, phenethylamine, 3-phenyl-1-propane, 4-methylbenzylamine, 2-methylbenzylamine, 4-isopropylbenzylamine, S-1-methylbenzylamine, 4-chlorobenzylamine, 4-bromobenzylamine, 3,4-dichlorobenzylamine, 4-methoxybenzylamine, 4-hydroxybenzylamine, 2-furanmethylamine, 2-thiophenemethylamine, 2-aminomethylpyridine, (S)-(-)-1-(1-naphthyl)ethylamine, 2-benzylamine, 1-aminopentane, 1-aminohexane, and cyclohexane.

[0026] When the reaction substrate is an aliphatic primary amine compound When the reaction produces urea compounds, they are linear benzyl symmetrical urea compounds. The aforementioned In this context, R6 is selected from H, substituted or unsubstituted C1-C. 12 The substituents are alkyl, substituted or unsubstituted C3-C8 cycloalkyl, substituted or unsubstituted phenyl, substituted or unsubstituted 5-12 membered heteroaryl, or substituted or unsubstituted 5-12 membered saturated or partially unsaturated heterocycles. The substituents of the alkyl, cycloalkyl, phenyl, heteroaryl, or heterocycle are independently selected from halogens, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy, OH, phenyl, and naphthyl groups, and the number of substituents is 1 to 2. The substituents can be substituted at any position on the alkyl, cycloalkyl, phenyl, heteroaryl, or heterocycle, and any two or more substituents can be the same or different.

[0027] The linear benzyl symmetric urea compound R6 in the reaction comes from the aliphatic primary amine compounds. R6 in the middle.

[0028] The linear benzyl symmetrical urea compounds can specifically be: N,N'-bis(benzyl)urea, N,N'-bis(2-phenylethyl)urea, N,N'-bis(2-phenylpropyl)urea, N,N'-bis(4-methylbenzyl)urea, N,N'-bis(2-methylbenzyl)urea, N,N'-bis(4-isopropylbenzyl)urea, N,N'-bis(S-1-methylbenzyl)urea, N,N'-bis(4-chlorobenzyl)urea, N,N'-bis(4-bromobenzyl)urea, N, N'-bis(3,4-dichlorobenzyl)urea, N,N'-bis(4-methoxybenzyl)urea, N,N'-bis(4-hydroxybenzyl)urea, N,N'-bis(furfuryl)urea, N,N'-bis(2-thiophenemethyl)urea, N,N'-bis(2-pyridinemethyl)urea, N,N'-bis(1-(naphthyl-1-yl)ethyl)urea, N,N'-bis(diphenylmethyl)urea, N,N'-dipentylurea, N,N'-dihexylurea, N,N'-dicyclohexylurea.

[0029] The inert solvent is selected from at least one of NMP, DMF, EG, THF, DMSO, 1,4-dioxane, HMPA, CH2Cl2, CHCl3, CCl4, toluene, ethyl acetate, and supercritical CO2.

[0030] The anion of the thiolate-based ionic liquid is a sulfur-containing ligand anion, selected from 4-amino-thiophenol anion ([4-AT-BT)). - ), 4-methoxy-thiophenol anion ([4-MeO-BT]) - ), 4-methyl-thiophene anion ([4-Me-BT) - ), 4-bromothiophenol anion ([4-Br-BT]) - ), 4-mercaptopyridine anion ([4-Tp]) - ), 2-mercaptopyridine anion ([2-Tp]) - ), benzyl thiol anion ([BnT)) - At least one of the following.

[0031] The cation of the thiolate-based ionic liquid is selected from tetrabutylphosphine cation ([TBP]). + Tetrabutylammonium cation ([TBA]) + Tetramethylammonium cation ([TMA]) + Tetraethylammonium cation ([TEA]) + ), choline cations ([Ch) + ), 1,8-diazabicyclo[5.4.0]undec-7-ene cation ([DBUH]) + At least one of the following.

[0032] The thiolate-based ionic liquid is formed by combining any one of the anions of the thiolate-based ionic liquid with any one of the cations of the thiolate-based ionic liquid.

[0033] The thiolate-based ionic liquid can be prepared using existing methods. As a specific embodiment, the preparation method of the thiolate-based ionic liquid includes: dissolving anionic and cationic ligands in a solvent, stirring at room temperature for at least 2 hours under an inert atmosphere, and then removing the solvent by freeze-drying to obtain the thiolate-based ionic liquid. The anionic ligand is selected from at least one of [4-AT-BT], [4-MeO-BT], [4-Me-BT], [4-Br-BT], [BnT], [4-Tp], and [2-Tp]. The cationic ligand is selected from at least one of [TBP][OH], [TBA][OH], [TMA][OH], [TEA][OH], [Ch][OH], and DBU. The solvent is selected from water or ethanol. The molar ratio of the anionic ligand to the cationic ligand is preferably about 1:1. The reaction time is preferably about 3 hours.

[0034] The molar ratio of the amine compound to CO2 is 1:2.0~20; for example: 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:14, 1:15, 1:18, 1:20.

[0035] The molar ratio of the amine compound to the thiolate-based ionic liquid is 1:0.02~1.5; for example: 1:0.05, 1:0.1, 1:0.2, 1:0.25, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.2, 1:1.5.

[0036] The reaction temperature is 100~160℃; for example, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃.

[0037] The method described above uses an aliphatic diamine compound as a substrate to react with CO2 to generate a 2-imidazolidine ketone compound. The reaction formula is as follows: .

[0038] The method described herein, in which aliphatic or alicyclic diamine compounds are used as substrates to react with CO2 to generate 2-imidazolidine ketone compounds, follows this reaction process (taking ethylenediamine as a substrate as an example): .

[0039] First, the amino group in ethylenediamine nucleophilically attacks CO2 to form intermediate 1-carbamate; subsequently, the anion RS in the thiolate-based ionic liquid... - The nucleophilic attack on intermediate 1 forms intermediate 2, a thiocarbamate; finally, intermediate 2 undergoes intramolecular nucleophilic attack cyclization to form 2-imidazolidine ketone and a catalyst thiolate ionic liquid, completing the catalytic cycle.

[0040] The method, when using aliphatic or alicyclic diamine compounds as substrates to react with CO2 to generate 2-imidazolidineone compounds: The anion of the thiolate-based ionic liquid is preferably [4-MeO-BT]. - [4-Me-BT] - At least one of the following; the cation of the thioglycol-based ionic liquid is selected from tetrabutylphosphine ([TBP]). + As a specific embodiment, the thiolate-based ionic liquid can be [TBP][4-MeO-BT], [TBP][4-Me-BT], [TBA][4-MeO-BT], or [TBA][4-Me-BT]. The solvent is preferably selected from at least one of EG, NMP, and DMSO; The preferred molar ratio of the diamine compound to CO2 is 1:3 to 10; The molar ratio of the diamine compound to the thiolate-based ionic liquid is preferably 1:0.5~1; The preferred reaction temperature is 130~150 ℃, for example 132 ℃, 135 ℃, 138 ℃, 142 ℃, 145 ℃, 148 ℃; The preferred reaction time is 16-36 hours.

[0041] The method described above uses o-phenylenediamine compounds as substrates to react with CO2 to generate benzimidazole ketone compounds. The reaction formula is as follows: .

[0042] The method described above, in which o-phenylenediamine compounds are used as substrates to react with CO2 to generate benzimidazole ketone compounds, involves the following reaction process: .

[0043] First, the anion RS in the thiol-based ionic liquid - Nucleophilic attack on CO2 forms a thiocarbonate intermediate; then, o-phenylenediamine compounds are activated by hydrogen bonding with the thiocarbonate intermediate to form intermediate 2. The nucleophilic nitrogen of intermediate 2 attacks the carbon atom of intermediate 3 (thiocarbonate intermediate) to form intermediate 4 and the thiolate-based ionic liquid catalyst, completing the catalytic cycle; subsequently, intermediate 4 dehydrates to produce intermediate 5 isocyanate; finally, intermediate 5 undergoes intramolecular nucleophilic attack cyclization and dehydration under the action of the thiolate-based ionic liquid catalyst to generate benzimidazolone compounds.

[0044] The method, when using o-phenylenediamine compounds as substrates to react with CO2 to generate benzimidazole ketone compounds; The anion of the thiolate-based ionic liquid is preferably [4-MeO-BT].- [4-Me-BT] - At least one of the following; the cation of the thioglycol-based ionic liquid is preferably tetrabutylphosphine ([TBP]). + As a specific embodiment, the thiolate-based ionic liquid can be [TBP][4-MeO-BT] or [TBP][4-Me-BT]. The solvent is preferably at least one of DMSO, MeCN, and DMF; The preferred molar ratio of the o-phenylenediamine compound to CO2 is 1:10 to 20; for example, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19. The molar ratio of the o-phenylenediamine compound to the thiolate-based ionic liquid is preferably 1:1 to 1.5; for example, 1:1.1, 1:1.2, 1:1.3, 1:1.4, or 1:1.5. The preferred reaction temperature is 130~150 ℃; for example, 132 ℃, 135 ℃, 138 ℃, 140 ℃, 142 ℃, 145 ℃, 148 ℃. The preferred reaction time is 12-24 hours, such as 16 hours, 18 hours, or 20 hours.

[0045] The method described above uses aliphatic primary amine compounds (taking benzylamine compounds as an example) as substrates to react with CO2 to generate linear benzyl symmetrical urea compounds. The reaction formula is as follows: .

[0046] The method described above uses aliphatic primary amine compounds as substrates to react with CO2 to generate linear benzyl symmetrical urea compounds. The reaction process is as follows (taking benzylamine compounds as substrates as an example): .

[0047] First, benzylamine nucleophilically attacks CO2 to form intermediate 1-carbamate, and the anion RS in the thiolate ionic liquid... - Nucleophilic attack on intermediate 1 forms intermediate 2; then, intermediate 2 breaks the C-OH bond to form intermediate 3 thiocarbamate and cationic ligand, intermediate 3 breaks the CS bond to generate intermediate 4 isocyanate and catalyst, completing the catalytic cycle; finally, another molecule of benzylamine attacks intermediate 4 isocyanate to produce N,N'-dibenzylurea.

[0048] The method, when using aliphatic primary amine compounds as substrates to react with CO2 to generate linear benzyl symmetrical urea compounds; The anion of the thiolate-based ionic liquid is preferably selected from [4-Br-BT]; the cation of the thiolate-based ionic liquid is selected from tetrabutylphosphine ([TBP]).+ As a specific embodiment, the thiolate-based ionic liquid can be [TBP][4-Br-BT]. The solvent is preferably NMP; The preferred molar ratio of the aliphatic primary amine compound to CO2 is 1:2.5 to 10; for example, 1:3.0, 1:3.5, 1:4.0, 1:4.5, 1:5.0, 1:5.5, 1:6.0, 1:6.5, 1:7.0, 1:7.5, 1:8.0, 1:8.5, 1:9.0, and 1:9.5. The pressure of CO2 in the reactor is preferably 1~1.7 MPa, for example 1.2, 1.5, 1.6 MPa; The preferred molar ratio of the aliphatic primary amine compound to the thiolate-based ionic liquid is 1:0.25 to 0.75; for example, 1:0.3, 1:0.35, 1:0.4, 1:0.45, 1:0.5, 1:0.55, 1:0.6, 1:0.65, or 1:0.7. The reaction temperature is 140~160 ℃; for example, 142℃, 145℃, 148℃, 150℃, 152℃, 155℃, 158℃.

[0049] A second objective of this invention is to provide a urea compound prepared by the method described in one objective of the invention.

[0050] Compared with the prior art, the beneficial effects of the present invention are as follows: Compared with existing methods for preparing urea compounds, this invention introduces thiol-based ionic liquids into the catalytic system, establishing a novel method for the efficient catalytic activation of CO2 to synthesize urea compounds. Its core advantages lie in the precise control of the cation and anion structures of the thiol-based ionic liquid, achieving highly efficient activation of CO2 and overcoming the three major bottlenecks of low solubility, difficult structural control, and poor recyclability of traditional inorganic sulfides NaSH, Na2S, or H2S in the organic phase during the catalytic activation of CO2 to synthesize urea compounds. Mechanistic studies show that the thiol groups in the ionic liquid, acting as strong nucleophilic sites, can efficiently activate inert CO2 molecules, promoting their reaction with amines to generate urea. Simultaneously, the tunability of the ionic liquid framework optimizes the nucleophilicity, microenvironment, and stability of the thiol, thus achieving universal catalysis for a variety of substrates under mild conditions. This strategy not only provides a novel "designable and recyclable" catalytic platform for the nonmetallic activation of CO2 but also opens up new avenues for the green and efficient utilization of carbon resources. Detailed Implementation

[0051] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0052] All reagents used in the following examples are commercially available products.

[0053] Example 1 Weigh out 2 mmol of ethylenediamine ( A thiolate-based ionic liquid (T-ILS) and 2 ml of solvent were added sequentially to the reaction vessel, and the vessel was tightened. The air inside the reaction vessel was purged three times using N2 and a vacuum pump. Then, CO2 was introduced, and the reaction was stirred at a specific temperature for a certain time. After the reaction was complete, the mixture was cooled to room temperature, the gas in the vessel was purged, and the mixture was extracted with ethyl acetate. The organic phases were combined and dried with anhydrous magnesium sulfate. The desiccant was removed by filtration, and the solvent was removed under reduced pressure to obtain the crude product. The crude product was purified by column chromatography (eluent: petroleum ether / ethyl acetate (V / V) = 20:1) to obtain the final product.

[0054] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, CDCl3): δ (ppm) 5.46 (s, 2H), 3.53 (s, 4H); 13 C NMR (126 MHz, CDCl3): δ (ppm) 165.6, 41.0. This indicates that the product is a 2-imidazolidineone with the following structure: .

[0055] The yields of 2-imidazolidineone under different reaction conditions are shown in Table 1.

[0056] Table 1

[0057] In the second column of Table 1, the numbers in parentheses after thiol-based ionic liquids represent the amount of the corresponding thiol-based ionic liquid used.

[0058] Examples 1-21 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with N-methylethylenediamine ( After obtaining the crude product, it was separated by wet-packing and dry-loading column chromatography (200-300 mesh silica gel): petroleum ether:ethyl acetate (V / V) = 20:1 was used as the developing solvent. The product yield was 65%. Product Use 1H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, CDCl3): d (ppm) 4.80 (s,1H), 3.41 (m, 4H), 2.79 (s, 3H); 13 C NMR (126 MHz, CDCl3): d (ppm) 163.2, 47.5, 38.1, 30.7. This indicates the product is N-methyl-2-imidazolidineone, with the following structure: .

[0059] Examples 1-22 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with N-ethylethylenediamine ( After obtaining the crude product, it was separated by wet-packing and dry-loading column chromatography (200-300 mesh silica gel): petroleum ether:ethyl acetate (V / V) = 20:1 was used as the developing solvent. The product yield was 85%.

[0060] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, CDCl3): d (ppm) 4.32 (s,1H), 3.48 – 3.38 (m, 4H), 3.26 (m, 2H), 1.13 (t, J = 7.2 Hz, 3H); 13 C NMR (126MHz, CDCl3): d (ppm) 162.6, 44.4, 38.3, 38.1, 12.7. This indicates the product is N-ethyl-2-imidazolidineone, with the following structure: .

[0061] Examples 1-23 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with 1,2-propanediamine ( After obtaining the crude product, it was separated by wet-packing and dry-loading column chromatography (200-300 mesh silica gel): petroleum ether:ethyl acetate (V / V) = 10:1 was used as the developing solvent. The product yield was 85%.

[0062] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, CDCl3): d(ppm) 5.02 (s,2H), 3.93 (m, 1H), 3.62 (t, J = 9.5 Hz, 1H), 3.09 (t, J = 8.7 Hz, 1H), 1.27 (d, J =3.9 Hz, 3H); 13 C NMR (126 MHz, CDCl3): d (ppm) 164.0, 484.5, 48.1, 21.3. This indicates the product is 4-methyl-2-imidazolidineone, with the following structure: .

[0063] Examples 1-24 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with 1,2-diamino-2-methylpropane ( After obtaining the crude product, it was separated by wet-packing and dry-loading column chromatography (200-300 mesh silica gel): petroleum ether:ethyl acetate (V / V) = 10:1 was used as the developing solvent. The product yield was 90%.

[0064] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, CDCl3): d (ppm) 4.79 (s,2H), 3.27 (s, 2H), 1.33 (s, 6H); 13 C NMR (126 MHz, CDCl3): d (ppm) 163.4, 55.2, 53.9, 28.4. This indicates that the product is 4,4-dimethyl-2-imidazolidineone, with the following structure: .

[0065] Examples 1-25 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with N,N-dimethylethylenediamine ( After the reaction was complete, the product was freeze-dried under reduced pressure, the solid was collected, and then dried to obtain a white powdery product. The product yield was 69%.

[0066] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, CDCl3): d (ppm) 3.27 (s,4H), 2.79 (s, 6H); 13C NMR (125 MHz, CDCl3): d (ppm) 162.1, 45.1, 31.6. This indicates that the product is 1,3-dimethyl-2-imidazolidineone, with the following structure: .

[0067] Examples 1-26 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with N,N-diethylethylenediamine ( After the reaction was complete, the product was freeze-dried under reduced pressure, the solid was collected, and then dried to obtain a white powdery product. The product yield was 90%.

[0068] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, CDCl3): d (ppm) 3.25 (s,4H), 3.20 (m, 4H), 1.06 (t, J = 7.3 Hz, 6H); 13 C NMR (125 MHz, CDCl3): d (ppm) 161.1, 42.1, 38.8, 12.8. This indicates that the product is 1,3-diethyl-2-imidazolidineone, with the following structure: .

[0069] Examples 1-27 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with N-phenylethylenediamine ( After obtaining the crude product, it was separated by wet-packing and dry-loading column chromatography (200-300 mesh silica gel): petroleum ether:ethyl acetate (V / V) = 10:1 was used as the developing solvent. The product yield was 90%.

[0070] Product Use 1 H and 13 Its structure was determined by C NMR spectroscopy: 1 H NMR (500 MHz, CDCl3): δ (ppm) 7.53(d, J = 8.4 Hz, 2H), 7.34 (t, J = 7.7 Hz, 2H), 7.06 (t, J = 7.5 Hz, 1H), 5.29 (s,1H), 3.94 (t, J = 7.9 Hz, 2H), 3.57 (t, J = 7.9 Hz, 2H);13 C10 NMR (126 MHz, CDCl3): δ (ppm) 159.98, 140.18, 128.96, 122.86, 118.03, 45.45, 37.65. This indicates that the product is N-phenyl-2-imidazolidineone, with the following structure: .

[0071] Examples 1-28 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with N,N-diisopropylethylenediamine ( After the reaction was complete, the product was freeze-dried under reduced pressure, the solid was collected, and then dried to obtain a white powdery product. The product yield was 89%.

[0072] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, D2O): d (ppm) 3.15 –3.07 (m, 2H), 2.98 (d, J = 2.2 Hz, 4H), 1.17 (d, J = 6.4 Hz, 12H); 13 C NMR (126MHz, D2O): d (ppm) 160.89, 49.38, 42.90, 19.76. This indicates the product is 1,3-diisopropyl-2-imidazolidineone, with the following structure: .

[0073] Examples 1-29 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with 1,3-propanediamine ( After the reaction was complete, the product was freeze-dried under reduced pressure, the solid was collected, and then dried to obtain a white powdery product. The product yield was 78%.

[0074] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, D2O): d (ppm) 5.46 (s,2H), 3.29 – 3.26 (t, 4H), 1.88 – 1.83(m, 2H); 13 C NMR (126 MHz, D2O): d (ppm) 158.81, 39.33, 20.22. This indicates the product is tetrahydropyrimidine-2(1H)-one, with the following structure: .

[0075] Examples 1-30 Using the preparation method of Examples 1-14, ethylenediamine was replaced with N,N-dimethyl-1,3-propanediamine ( After obtaining the crude product, it was separated by wet-packing and dry-loading column chromatography (200-300 mesh silica gel): petroleum ether:ethyl acetate (V / V) = 1:1 was used as the developing solvent. The product yield was 80%.

[0076] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 (TMS): d (ppm) 3.15 (t, J = 5.9 Hz, 2H), 3.09 (t, J = 4.5 Hz, 2H), 2.74 (s, 6H), 1.79 (m, 2H); 13 CNMR (126 MHz, DMSO- d6 ): d (ppm) 155.7, 47.0, 34.4, 22.0. This indicates that the product is 1,3-dimethyltetrahydropyrimidine-2(1H)-one, with the following structure: .

[0077] Examples 1-31 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with N-ethyl-1,3-propanediamine ( After the reaction was complete, the product was freeze-dried under reduced pressure, the solid was collected, and then dried to obtain a white powdery product. The product yield was 83%.

[0078] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, D2O) d (ppm) 4.80 (s,1H), 3.39 – 3.19 (m, 6H), 1.90 (q, J = 7.1 Hz, 2H), 1.08 (t, J = 7.6 Hz, 3H); 13 CNMR (126 MHz, D2O) d(ppm) 157.79, 44.53, 42.16, 39.53, 21.07, 11.93. This indicates the product is 1-ethyltetrahydropyrimidine-2(1H)-one, with the following structure: .

[0079] Examples 1-32 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with dimethylpropylenediamine (EPD). After the reaction was complete, the product was freeze-dried under reduced pressure, the solid was collected, and then dried to obtain a white powdery product. The product yield was 80%.

[0080] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): d (ppm) 6.06(s, 2H), 2.76 (s, 4H), 0.94 (s, 6H); 13 C NMR (126 MHz, DMSO- d6 ): d (ppm) 155.3, 51.1, 27.2, 23.9. This indicates that the product is 5,5-dimethyltetrahydropyrimidine-2(1H)-one, with the following structure: .

[0081] Examples 1-33 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with N-isopropyl-1,3-propanediamine ( After the reaction was complete, the product was freeze-dried under reduced pressure, the solid was collected, and then dried to obtain a white powdery product. The product yield was 83%.

[0082] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, D2O): δ (ppm) (dd, J =13.9, 8.8, 5.1 Hz, 1H), 3.21 (t, J = 7.2 Hz, 4H), 1.91 – 1.83 (m, 2H), 1.10 (d, J = 6.8 Hz, 6H); 13C NMR (126 MHz, D2O): δ (ppm) 157.49, 44.94, 39.27, 37.87, 21.06, 18.53. This indicates that the product is 1-isopropyltetrahydropyrimidine-2(1H)-one, with the following structure: .

[0083] Examples 1-34 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with 1,2-diphenylethylenediamine ( After the reaction was completed, the mixture was cooled to room temperature, the gas in the reactor was purged, and the reaction solution was extracted with ethyl acetate and water. The ethyl acetate layer was then distilled under reduced pressure to obtain a white flocculent solid, which was the product. The product yield was 85%.

[0084] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, CDCl3): d (ppm) 7.53 –7.14 (m, 10H), 5.01 (s, 2H), 4.61 (s, 2H); 13 C NMR (126 MHz, CDCl3): d (ppm) 162.3, 139.8, 128.9, 128.5, 126.5, 66.0. This indicates the product is 4,5-diphenyl-2-imidazolidineone, with the following structure: .

[0085] Examples 1-35 The preparation method of Examples 1-14 was used, but ethylenediamine was replaced with 1,2-cyclohexanediamine ( After obtaining the crude product, it was separated by wet-packing and dry-loading column chromatography (200-300 mesh silica gel): petroleum ether:ethyl acetate (V / V) = 1:1 was used as the developing solvent. The product yield was 83%.

[0086] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, CDCl3): d (ppm) 4.75(s, 2H), 3.84 – 3.51 (m, 2H), 1.91 – 1.43 (m, 6H), 1.42 – 1.03 (m, 2H); 13 C NMR (126 MHz, CDCl3): d(ppm) 165.1, 52.5, 28.9, 20.9. This indicates the product is octahydro-2H-benzimidazol-2-one, with the following structure: .

[0087] Examples 1-36 Using the preparation method of Examples 1-14, ethylenediamine was replaced with N,N-dimethyl-1,2-cyclohexanediamine ( After obtaining the crude product, it was separated by wet-packing and dry-loading column chromatography (200-300 mesh silica gel): petroleum ether:ethyl acetate (V / V) = 1:1 was used as the developing solvent. The product yield was 88%.

[0088] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, CDCl3): δ (ppm) 2.48 (s, 6H), 2.14 (s, 2H), 1.38 (s, 4H), 0.83 (s, 4H); 13 C NMR (126 MHz, CDCl3): δ (ppm) 40.54, 23.42, 18.18, 13.07. This indicates that the product is 1,3-dimethyloctahydro-2H-benzimidazol-2-one with the following structure: .

[0089] Example 2 Weigh out 1 mmol of o-phenylenediamine ( A thiolate-based ionic liquid (T-ILS) and 2 ml of solvent were sequentially added to the reaction vessel, and the vessel was tightened. The vessel was then purged three times with N2 until all air was removed. CO2 was then introduced into the reaction vessel, and the mixture was stirred at a specific temperature for a certain time. After the reaction was complete, the mixture was cooled to room temperature, and the gas in the reaction vessel was slowly purged. Finally, 40 ml of distilled water was added to the reaction mixture to allow the product to precipitate completely. The product was then obtained by filtration and drying for 4 hours.

[0090] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO-d6, TMS): δ(ppm) 10.57 (s, 2H), 6.91 (s, 4H); 13C NMR (125 MHz, DMSO-d6, TMS): δ (ppm) 155.28, 129.67, 120.43, 108.46. This indicates that the product is benzimidazol-2-one, with the following structure: .

[0091] The yields of benzimidazole-2-one under different reaction conditions are shown in Table 2.

[0092] Table 2

[0093] In the second column of Table 2, the numbers in parentheses after thiolate-based ionic liquids represent the amount of the corresponding thiolate-based ionic liquid used.

[0094] Example 2-18 Using the preparation method of Examples 2-17, o-phenylenediamine was replaced with 6-methyl-o-phenylenediamine ( The product yield was 94%.

[0095] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 (TMS): d (ppm)10.65 (s, 1H), 10.53(s, 1H), 6.82 (t, J = 7.1 Hz, 1H), 6.73 (t, J = 7.5 Hz, 2H), 2.25 (s, 3H); 13 C NMR (125 MHz, DMSO- d6 (TMS): d (ppm) 155.47, 129.23, 128.55,121.56,120.34, 117.13, 106.05, 16.17.HRMS (ESI): m / z Calcd for C8H8N2O [MH] - :148.0637, Found 147.0572. Note: The product is 6-methylbenzimidazol-2-one, with the following structure: .

[0096] Example 2-19 Using the preparation method of Examples 2-17, o-phenylenediamine was replaced with 5,6-dimethyl-o-phenylenediamine ( The product yield was 93%.

[0097] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 (TMS): d (ppm)10.34 (s, 2H), 6.70(s, 2H), 2.17(s, 6H); 13 C NMR (125 MHz, DMSO- d6 (TMS): d (ppm)155.89, 128.22, 110.01, 19.85.HRMS (ESI) m / z Calcd for C9H 10 N2O [MH] - :162.0793, Found 162.0729. This indicates that the product is 5,6-dimethylbenzimidazole-2-one, with the following structure: .

[0098] Example 2-20 Using the preparation method of Examples 2-17, o-phenylenediamine was replaced with 5-tert-butyl-o-phenylenediamine ( The product yield was 94%.

[0099] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 (TMS): d (ppm) 10.45 (s, 2H), 6.94 (d, J = 8.2 Hz,1H), 6.90 (s, 1H), 6.83(d, J = 8.1 Hz, 1H), 1.25 (s, 9H); 13 C NMR (125 MHz, DMSO- d6 (TMS): d (ppm) 155.54, 143.12, 129.56, 127.37, 117.20, 107.89, 105.38, 34.19, 31.56. This indicates the product is 5-tert-butylbenzimidazole-2-one, with the following structure: .

[0100] Example 2-21 Using the preparation method of Examples 2-17, o-phenylenediamine was replaced with naphthalene-2,3-diamine ( The product yield was 95%.

[0101] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 (TMS): d (ppm)10.81 (s, 2H), 7.80 (s, 2H), 7.31 (s, 4H); 13 C NMR (125 MHz, DMSO- d6, TMS): d (ppm) 156.21, 131.07, 129.22, 126.83, 123.25, 103.60.HRMS (ESI) m / z Calcd forC 11 H8N2O [MH] - : 184.0673, Found 183.0566. This indicates the product is naphthalimidazol-2-one, with the following structure: .

[0102] Example 2-22 Using the preparation method of Examples 2-17, o-phenylenediamine was replaced with 5-fluoro-o-phenylenediamine ( The product yield was 81%.

[0103] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 (TMS): d (ppm)10.74 (s, 1H), 10.63 (s, 1H), 6.93 – 6.82 (m, 1H), 6.74 (dd, J = 22.8 Hz, 8.8 Hz, 2H); 13 C NMR (125 MHz, DMSO- d6 (TMS): d (ppm) 158.39, 155.66 (d, J = 110.2 Hz), 130.33 (d, J= 12.9 Hz), 126.04, 109.08 – 107.53 (m), 106.48 (d, J = 23.8 Hz), 96.47 (d, J = 28.1 Hz).HRMS (ESI) m / z Calcd for C7H5FN2O [MH] - 152.0386, Found 151.0317. Note: The product is 5-fluorobenzimidazole-2-one, with the following structure: .

[0104] Example 2-23 Using the preparation method of Examples 2-17, o-phenylenediamine was replaced with 5-bromo-o-phenylenediamine ( The product yield was 94%.

[0105] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 (TMS): d (ppm) 10.76 (s, 2H), 7.06 (d, J = 11.9 Hz, 2H), 6.87 (d, J = 7.6 Hz, 1H); 13 C NMR (125MHz, DMSO- d6 (TMS): d (ppm) 155.05, 131.20, 128.98, 122.90, 112.01, 111.04, 110.07. This indicates the product is 5-bromobenzimidazole-2-one, with the following structure: .

[0106] Example 2-24 Using the preparation method of Examples 2-17, o-phenylenediamine was replaced with 4,5-dichloro-o-phenylenediamine ( The product yield was 86%.

[0107] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 (TMS): d (ppm)10.91 (s, 2H), 7.09 (s, 2H); 13C NMR (125 MHz, DMSO- d6 (TMS): d (ppm) 155.17, 129.82, 122.35, 109.73. This indicates the product is 4,5-dichlorobenzimidazole-2-one, with the following structure: .

[0108] Example 2-25 Using the preparation method of Examples 2-17, o-phenylenediamine was replaced with 4-bromo-5-methyl-o-phenylenediamine ( The product yield was 94%.

[0109] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 (TMS): d (ppm)10.68 (s, 1H), 10.60 (s, 1H), 7.06 (s, 1H), 6.90 (s, 1H), 2.30 (s, 3H); 13 C NMR (125 MHz, DMSO-) d6 (TMS): d (ppm) 155.18, 129.52, 129.1, 128.43, 114.33,111.47, 110.50, 22.37.HRMS (ESI) m / z Calcd for C8H7BrN2O [MH] - : 255.9742, Found 224.9674. Note: The product is 4-bromo-5-methylbenzimidazol-2-one, with the following structure: .

[0110] Example 2-26 Using the preparation method of Examples 2-17, o-phenylenediamine was replaced with 3-bromo-4-fluoroo-phenylenediamine ( The product yield was 80%.

[0111] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 (TMS): d (ppm)11.26 (s, 1H), 10.91 (s, 1H), 6.89 (s, 2H); 13C NMR (125 MHz, DMSO- d6 TMS): d (ppm) 155.85, 155.03, 153.17, 130.78, 126.82, 109.13-106.60 (m), 88.98. HRMS (ESI) m / z Calcd for C7H4BrFN2O [MH] - : 229.9491, Found 228.9423. The product is 3-bromo-4-fluorobenzimidazol-2-one, with the following structure: .

[0112] Example 2-27 Using the preparation method of Examples 2-17, o-phenylenediamine was replaced with 4-trifluoromethyl-o-phenylenediamine ( The product yield was 64%.

[0113] Product Use 1 H and 13 Its structure was determined by C NMR spectroscopy: 1 H NMR (500 MHz, DMSO- d6 (TMS): d (ppm)11.05 (s, 1H), 10.96 (s, 1H), 7.28 (d, J = 8.1 Hz, 1H), 7.16 (s, 1H), 7.09 (d, J = 8.1 Hz, 1H); 13 C NMR (125 MHz, DMSO- d6 TMS): d (ppm) 155.31, 132.84, 129.82,124.85 (d, J = 271.1 Hz), 121.03 (q, J = 31.8 Hz), 117.84, 108.53, 104.90. HRMS (ESI) m / z Calcd for C8H5F3N2O [MH] - : 202.0354, Found 201.0286. The product is 4-trifluoromethylbenzimidazole-2-one, with the following structure: .

[0114] Example 2-28 Using the preparation method of Examples 2-17, o-phenylenediamine was replaced with methyl 3,4-diaminobenzoate ( The product yield was 75%.

[0115] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 (TMS): d (ppm)9.13 (s, 1H),8.29 (s, 1H), 7.86 (d, J = 8.4 Hz, 1H), 7.72 (s, 1H), 3.89 (s, 3H); 13 C NMR (125 MHz, DMSO- d6 (TMS): d (ppm) 165.68, 155.65, 137.83, 134.15,125.91, 125.75, 121.76, 119.57,51.57. The product is methyl 2-oxo-2,3-dihydro-1H-benzo[d]imidazolium-5-carboxylate, with the following structure: .

[0116] Example 2-29 Using the preparation method of Examples 2-17, o-phenylenediamine was replaced with 4-nitro-o-phenylenediamine ( The product yield was 45%.

[0117] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 (TMS): d (ppm)11.38 (s, 1H),11.20 (s, 1H), 7.91 (d, d, J = 5.0 Hz, 1H), 7.71 (s, 1H), 7.10(d, J = 5.0 Hz, 1H); 13 C NMR (125 MHz, DMSO- d6 (TMS): d (ppm) 155.36, 146.12,135.17, 130.88, 123.72, 116.72, 114.17. The product is 4-nitro-benzimidazole-2-one, with the following structure: .

[0118] Example 3 2 mmol of benzylamine was added sequentially into a 15 mL high-pressure reactor. Prepare a reaction vessel by adding 2 ml of thiolate-based ionic liquid (T-ILS) and 2 ml of solvent, and tighten the vessel. Introduce CO2 into the reaction vessel and then react at a specific temperature for a specific time. After the reaction is complete, add a certain amount of distilled water to the reaction solution to allow the product to precipitate completely. Then, obtain the product by sequentially filtering and drying.

[0119] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): d (ppm) 7.31(t, J = 7.5 Hz, 4H), 7.28 – 7.18 (m, 6H), 6.43 (t, J = 5.0 Hz, 2H), 4.23 (d, J = 5Hz, 4H); 13 C NMR (126 MHz, DMSO- d6 ): d (ppm) 158.08, 140.89, 128.19, 126.96,126.52, 42.98.MS (ESI): m / z calcd for C 15 H 17 N2O [M+H] + : 241.10, found 241 13,mp:168-169 ℃. The product is N,N'-bis(benzyl)urea, and its structure is as follows: .

[0120] The yields of N,N'-bis(benzyl)urea under different reaction conditions are shown in Table 3.

[0121] Table 3

[0122] In the second column of Table 3, the numbers in parentheses after thiol-based ionic liquids represent the amount of the corresponding thiol-based ionic liquid used.

[0123] Example 3-25 The preparation method of Examples 3-22 was used, but benzylamine was replaced with 3-phenyl-1-propylamine ( The product was then processed to obtain a white powdery product. The product yield was 91%.

[0124] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): d (ppm) 7.26(t, J = 7.5 Hz, 4H), 7.17 (dd, J 1 = 15.1Hz J 2 = 7.4 Hz, 6H), 5.88 (d, J = 5.0 Hz, 2H), 2.98 (t, J = 7.5 Hz, 4H), 2.58 – 2.53 (m, 4H), 1.65 (q, J = 5.0 Hz, 4H); 13 CNMR (126 MHz, DMSO- d6 ): d (ppm) 158.22, 141.91, 128.33, 128.32, 125.74, 38.84,32.58, 31.93. The product is N,N'-bis(2-phenylpropyl)urea, with the following structure: .

[0125] Example 3-26 The preparation method of Examples 3-22 was used, except that benzylamine was replaced with 2-methylbenzylamine ( The product was then processed to obtain a white powdery product. The product yield was 92%.

[0126] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): δ (ppm) 7.20 (d, J = 5.0 Hz, 2H), 7.14 (s, 6H), 6.27 (t, J = 5.0 Hz, 2H), 4.21 (d, J = 5.0Hz, 4H), 2.26 (s, 6H); 13C NMR (126 MHz, DMSO- d6 ): δ (ppm) 157.93, 138.37,135.45, 129.94, 127.22, 126.73, 125.77, 41.02, 18.58. The product is N,N'-bis(2-methylbenzyl)urea, with the following structure: .

[0127] Example 3-27 The preparation method of Examples 3-22 was used, but benzylamine was replaced with 4-isopropylbenzylamine ( A white solid product was obtained. The product yield was 89%.

[0128] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): d (ppm) 7.16(s, 8H), 6.33 (t, J = 5.0 Hz, 2H), 4.17 (d, J = 5.0 Hz, 4H), 2.85 (hept, J = 5.0Hz, 2H), 1.18 (d, J =10.0 Hz, 12H); 13 C NMR (126 MHz, DMSO- d6 ): d (ppm) 157.92,146.59, 138.11, 126.98, 125.97, 42.67, 33.01, 23.87. MS (ESI): m / z calcd for C 21 H 29 N2O [M+H] + : 325.15, found 325.23, mp:122-123 ℃. The product is N,N'-bis(4-isopropylbenzyl)urea, with the following structure: .

[0129] Example 3-28 The preparation method of Examples 3-22 was used, but benzylamine was replaced with α-methylbenzylamine ( The product was then processed to obtain a yellow powder. The product yield was 90%.

[0130] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): d (ppm) 7.35– 7.15 (m, 10H), 6.27 (d, J = 8.1 Hz, 2H), 4.72 (q, J = 7.0 Hz, 2H), 1.30 (dd, J =10.8, 7.5 Hz, 6H); 13 C NMR (126 MHz, DMSO- d6 ): d (ppm) 156.54, 145.67, 128.27,126.50, 125.72, 48.50, 23.40.MS (ESI): m / z calcd for C 17 H 21 N2O [M+H] + : 269.10, found 269.17, mp: 122-123 ℃. The product is N,N'-bis(α-methylbenzyl)urea, with the following structure: .

[0131] Example 3-29 The preparation method of Examples 3-22 was used, but benzylamine was replaced with 4-chlorobenzylamine ( A white crystalline product was obtained. The product yield was 89%.

[0132] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): d (ppm) 7.35 (d, J = 5.0 Hz, 4H), 7.25 (d, J = 5.0 Hz, 4H), 6.66 (t, J = 7.5 Hz, 2H), 4.20 (d, J =5.0 Hz, 4H); 13 C NMR (126 MHz, DMSO- d6 ): d(ppm) 158.20, 140.09, 131.09, 128.88,128.19, 42.34. The product is N,N'-bis(4-chlorobenzyl)urea, with the following structure: .

[0133] Examples 3-30 The preparation method of Examples 3-22 was used, but benzylamine was replaced with 4-bromobenzylamine ( The product was then processed to obtain a grayish-white crystalline product. The product yield was 88%.

[0134] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): δ (ppm) 7.49 (d, J = 10.0 Hz, 4H), 7.19 (d, J = 5.0Hz, 4H), 6.53 (t, J = 5.0 Hz, 2H), 4.17(d, J = 5.0 Hz, 4H); 13 C NMR (126 MHz, DMSO- d6 ): δ (ppm) 158.10, 140.50, 131.11,129.27, 119.56, 42.42. The product is N,N'-bis(4-bromobenzyl)urea, with the following structure: .

[0135] Example 3-31 The preparation method of Examples 3-22 was used, except that benzylamine was replaced with 3,4-dichlorobenzylamine ( A white solid product was obtained. The product yield was 85%.

[0136] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): δ (ppm) 7.49 (d, J = 10.0 Hz, 4H), 7.19 (d, J = 5.0 Hz, 4H), 6.53 (t, J = 5.0 Hz, 2H), 4.17(d, J= 5.0 Hz, 4H); 13 C NMR (126 MHz, DMSO- d6 ): δ (ppm) 158.10, 140.50, 131.11,129.27, 119.56, 42.42.MS (ESI): m / z calcd for C 15 H 16 Br2N2NaO2[M+Na+H2O] + :439.95, found 439.95, mp: 268-270 ℃. The product is N,N'-bis(3,4-dichlorobenzyl)urea, with the following structure: .

[0137] Example 3-32 The preparation method of Examples 3-22 was used, but benzylamine was replaced with 4-methoxybenzylamine ( The product was then processed to obtain a pale yellow solid. The product yield was 85%.

[0138] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): d (ppm) 7.16 (d, J = 5.0 Hz, 4H), 6.86 (d, J = 5.0Hz, 4H), 6.30 (s, 2H), 4.14 (s, 4H), 3.72(s, 6H); 13 C NMR (126 MHz, DMSO- d6 ): d (ppm) 158.15, 158.6, 132.79, 128.40,113.70, 55.13, 42.50.MS (ESI): m / z calcd for C 17 H 21 N₂O₃[M+H] + : 301.10, found301.16, mp:178-180 ℃. The product is N,N'-bis(4-methoxybenzyl)urea, with the following structure: .

[0139] Example 3-33 The preparation method of Examples 3-22 was used, but benzylamine was replaced with 4-hydroxybenzylamine ( The product was then processed to obtain a white powdery product. The product yield was 84%.

[0140] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): d (ppm) 9.23 (s, 2H), 7.04 (d, J = 10.0 Hz, 4H), 6.68 (d, J = 5.0 Hz, 4H), 6.18 (d, J = 5.0 Hz, 2H), 4.08 (d, J =5.0 Hz, 4H); 13 C NMR (126 MHz, DMSO- d6 ): d (ppm) 157.97, 156.08,130.92, 128.38, 114.95, 42.57.MS (ESI): m / z calcd for C 15 H 17 N₂O₃[M+H] + : 273.05, found 273.12, mp: 185-187 ℃. The product is N,N'-bis(4-hydroxybenzyl)urea, with the following structure: .

[0141] Examples 3-34 The preparation method of Examples 3-22 was used, but benzylamine was replaced with 2-furanylamine ( The product was then processed to obtain a white powdery product. The product yield was 89%.

[0142] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): d (ppm) 7.55(s, 2H), 6.40 – 6.30 (m, 4H), 6.18 (d, J = 5.0 Hz, 2H), 4.20 (d, J = 5.0 Hz, 4H); 13C NMR (126 MHz, DMSO- d6 ): d (ppm) 157.40, 143.21, 142.89, 110.62, 110.41,37.95.MS (ESI): m / z calcd for C 11 H 13 N₂O₃[M+H] + : 221.00, found 221.09, mp:126-128 ℃. The product is N,N'-bis(furfurylamino)urea, with the following structure: .

[0143] Examples 3-35 The preparation method of Examples 3-22 was used, but benzylamine was replaced with 2-thiophene methylamine ( The product was obtained as a brownish-yellow powder. The product yield was 75%.

[0144] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): d (ppm) 7.35 (d, J = 5.0 Hz, 2H), 6.94 (d, J = 5.0 Hz, 4H), 6.50 (t, J = 5.0 Hz, 2H), 4.38 (d, J =5.0 Hz, 4H); 13 C NMR (126 MHz, DMSO- d6 ): d (ppm) 157.40, 144.22, 127.11, 126.60,124.66, 38.12.MS (ESI): m / z calcd for C 11 H 13 N2OS2[M+H] + : 253.00, found 253.05,mp: 163-165 ℃. The product is N,N'-bis(2-thiophenemethyl)urea, with the following structure: .

[0145] Examples 3-36 The preparation method of Examples 3-22 was used, but benzylamine was replaced with 2-aminomethylpyridine ( After the reaction was complete, a pale yellow oily product was obtained by separation column separation. The product yield was 90%.

[0146] Product Use 1 H and 13 Its structure was determined by C NMR spectroscopy: 1 H NMR (500 MHz, DMSO- d6 ): d (ppm) 8.50 (d, J = 4.7 Hz, 2H), 7.76 (t, J = 7.6 Hz, 2H), 7.30 (d, J = 7.8 Hz, 2H), 7.28 –7.21 (m, 2H), 6.75 (t, J = 5.8 Hz, 2H), 4.34 (d, J = 5.8 Hz, 4H); 13 C NMR (126 MHz, DMSO- d6 ): d (ppm) 159.69, 158.12, 148.69, 136.62, 121.90, 120.84, 44.96. The product is N,N'-bis(2-pyridinemethyl)urea, with the following structure: .

[0147] Examples 3-37 Using the preparation method of Examples 3-22, benzylamine was replaced with (R)-1-(1-naphthyl)ethylamine. A white powdery product was obtained. The product yield was 78%.

[0148] Product Use 1 H and 13 Its structure was determined by C NMR spectroscopy: 1 H NMR (500 MHz, DMSO- d6 ): d (ppm) 8.15 (d, J = 10.0 Hz, 1H), 8.08 (d, J = 10.0 Hz, 1H), 7.97 – 7.89 (m, 2H), 7.85 – 7.77(m, 2H), 7.60 – 7.42 (m, 8H), 6.42 (dd, J 1 = 22.5 HzJ 2 = 7.5 Hz, 2H), 5.55 (h, J =7.5 Hz, 2H), 1.46 (dd, J 1 = 22.5 Hz J 2 = 7.5 Hz, 6H); 13 C NMR (126 MHz, DMSO- d6 ): d (ppm) 156.36, 141.29, 137.5, 133.41, 130.42, 128.57, 127.14, 126.04, 125.54,123.24, 121.84, 44.65, 22.53.

[0284] MS (ESI): m / z calcd for C 25 H 25 N2O [M+H] + :369.15, found 369.20, mp: 223-225 ℃. The product is N,N'-bis((R)-1-(1-naphthyl))ethylurea, with the following structure: .

[0149] Examples 3-38 The preparation method of Examples 3-22 was used, but benzylamine was replaced with 2-phenylmethylamine ( The product was then processed to obtain a pale yellow solid. The product yield was 78%.

[0150] Product Use 1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, DMSO- d6 ): d (ppm) 7.31 (d, J = 10.0 Hz, 8H), 7.28 – 7.18 (m, 12H), 6.95 (d, J = 5.0 Hz, 2H), 5.87 (d, J =5.0 Hz, 2H); 13 C NMR (126 MHz, DMSO- d6 ): d (ppm) 156.79, 144.01, 128.87, 127.25,127.22, 59.1.MS (ESI): m / z calcd for C 27 H25 N2O [M+H] + : 393.15, found 393.20,mp: 283-284 ℃. The product is N,N'-bis(diphenylmethyl)urea, with the following structure: .

[0151] Examples 3-39 The preparation method of Examples 3-22 was used, but benzylamine was replaced with 1-aminohexane ( The product was then processed to obtain a white powdery product. The product yield was 65%.

[0152] Product Use 1 H and 13 Its structure was determined by C NMR spectroscopy: 1 H NMR (500 MHz, Chloroform- d ): d (ppm) 4.71 (d, J = 5.0 Hz, 2H), 3.14 (q, J = 6.7 Hz, 4H), 1.48 (d, J = 6.3 Hz, 4H), 1.30(dt, J 1 = 15.9 Hz J 2 = 5.5 Hz, 12H), 0.88 (t, J = 5.0 Hz, 6H); 13 C NMR (126 MHz, Chloroform- d ): d (ppm) 158.62, 40.58, 31.59, 30.29, 26.63, 22.60, 14.03. MS (ESI): m / z calcd for C 13 H 29 N2O [M+H] + : 229.20,found 229.23, mp:73-76 ℃. The product is N,N'-dihexylurea, with the following structure: .

[0153] Examples 3-40 The preparation method of Examples 3-22 was used, but benzylamine was replaced with cyclohexane ( The process yielded a white crystalline product. The product yield was 70%.

[0154] Product Use1 H and 13 Its structure was determined by C NMR spectrum: 1 H NMR (500 MHz, TFA- d ): d (ppm) 5.11(s,2H), 3.54(d, J = 9.8 Hz, 4H), 3.35 (d, J = 10.0 Hz, 4H), 3.22(d, J = 11.6 Hz, 2H), 2.86(ddt, J = 42.0, 22.0, 11.2 Hz, 12H); 13 C NMR (126 MHz, TFA- d ): d (ppm) 159.93, 55.32,35.04, 27.30, 26.93.MS(ESI):m / z calcd for C 13 H 25 N₂O[M+H] + : 225.10, found225.20, mp:229-230 ℃ The product is N,N'-dicyclohexylurea, with the following structure: .

[0155] In this invention, yield = ×100%.

Claims

1. A method for preparing urea compounds, comprising: In an inert solvent, thiolate-based ionic liquids catalyze the reaction of CO2 with amine compounds; the reaction temperature is 100~160℃. The amine compounds are selected from aliphatic diamine compounds, alicyclic diamine compounds, and aliphatic primary amine compounds; The urea compounds are selected from 2-imidazolidine ketone compounds and linear benzyl symmetrical urea compounds; The thiolate-based ionic liquid is selected from at least one of [TBP][4-MeO-BT], [TBA][4-MeO-BT], [TBA][4-Me-BT], and [TBP][4-Br-BT]. The inert solvent is selected from at least one of NMP, DMF, EG, DMSO, 1,4-dioxane, HMPA, CH2Cl2, CHCl3, CCl4, toluene, ethyl acetate, and supercritical CO2. The chemical formula of the aliphatic diamine compound is: ; The chemical formula of the alicyclic diamine compound is: ; The chemical formula of the aliphatic primary amine compound is: ; The chemical formula of the 2-imidazolidineone compound is: or ; The chemical formula of the linear benzyl symmetrical urea compound is: ; R1, R2, R3, and R4 are independently selected from: H, C1-C6 alkyl, C1-C6 alkoxy, NH2, NO2, SO2CH3, substituted or unsubstituted phenyl groups; the substituents of the phenyl group are selected from at least one of C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy, NH2, NO2, and SO2CH3, and the number of substituents is 1 to 4; R a R b R c Independently selected from: H, C1-C6 alkyl groups; n=1~3； R6 is selected from H, substituted or unsubstituted C1-C. 12 Alkyl, substituted or unsubstituted C3-C8 cycloalkyl, substituted or unsubstituted phenyl, substituted or unsubstituted 5-12-membered heteroaryl, substituted or unsubstituted 5-12-membered saturated or partially unsaturated heterocycle; the substituents of the alkyl, cycloalkyl, phenyl, heteroaryl or heterocycle are independently selected from halogen, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy, OH, phenyl, naphthyl, and the number of substituents is 1 to 2.

2. The method as described in claim 1, characterized in that, The molar ratio of the amine compound to CO2 is 1:2.0~20, or / and, The molar ratio of the amine compound to the thiolate-based ionic liquid is 1:0.02~1.

5.

3. The method as described in claim 1, characterized in that, The thiolate-based ionic liquid is selected from at least one of [TBP][4-MeO-BT], [TBA][4-MeO-BT], and [TBA][4-Me-BT]. The molar ratio of the diamine compound to CO2 is 1:3~10; The molar ratio of the diamine compound to the thiolate-based ionic liquid is 1:0.5~1; The reaction temperature is 130~150℃.

4. The method as described in claim 1, characterized in that, The thiolate-based ionic liquid is [TBP][4-Br-BT]; The molar ratio of the aliphatic primary amine compound to CO2 is 1:2.5~10; The molar ratio of the aliphatic primary amine compound to the thiolate-based ionic liquid is 1:0.25~0.75; The reaction temperature is 140~160℃.

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