New process for preparing carbonic ester with participation of arylmethyl halogenated hydrocarbon and green co-production technology

Abstract

The invention relates to the field of new material chemicals, and firstly realizes green co-production preparation of symmetric carbonate or asymmetric carbonate by taking alkyl carbonate salt and aryl methyl halogenated hydrocarbon as initial raw materials through two-step reaction, and a byproduct is aryl methyl alcohol. The whole process does not involve traditional highly toxic raw materials such as phosgene, so that generation of waste materials is avoided, and conversion from low-cost raw materials to high-added-value products is realized.

Description

[Technical field]

[0001] The present invention relates to the field of new material chemicals, and in particular to a new method and technology for preparing symmetrical carbonates (same hydrocarbon substituents) or asymmetrical carbonates (different hydrocarbon substituents) and aromatic methyl alcohols by green co-production through two-step reaction using hydrocarbon carbonate salts and aromatic methyl halogenated hydrocarbons as starting materials. These carbonates have a wide range of uses and can be used as green solvents with excellent performance, main components of new energy battery electrolytes, gasoline additives, precursor raw materials for carbonate resin manufacturing, raw materials for pharmaceutical synthesis, etc. [Background technology]

[0002] Symmetrical carbonates (same hydrocarbon substituents) and asymmetric carbonates (different hydrocarbon substituents) are a new generation of cornerstone green chemical raw materials with excellent performance; for example, dimethyl carbonate (DMC) or ethyl methyl carbonate plays an important role in low VOCs emission green solvents, new energy battery electrolytes, and carbonate resin manufacturing.

[0003] Carbonate substances are usually made by condensing phosgene with alcohol, or by transesterifying ethylene carbonate with different alcohols. The process is demanding, the cost is high, and the selectivity is poor. With the continuous development of carbonate technology and products in recent years, especially the growing demand for green coatings and new energy battery systems, carbonate compounds have seen rapid capacity expansion. New cost-reducing, efficiency-enhancing, and green and environmentally friendly production process technologies are major industrial research topics that the industry is striving for.

[0004] Relevant industry technicians are committed to exploring the direct esterification of alcohols and carbon dioxide to prepare carbonates, but the process principle is unfavorable in terms of chemical thermodynamics, so it requires the intervention of catalysts and harsh reaction conditions. A recent industry review reviewed in detail the various catalysts or promoter systems reported so far (Energies 2022, 15, 5133), but they generally have insufficient reaction activity or are easily deactivated and ineffective, with low conversion rates and product yields, and high costs. Therefore, this route still needs further continuous research and development.

[0005] In our previous applications, we have disclosed a technical process for using simple and readily available raw materials, namely alcohol or phenol, carbon dioxide and sulfate, to directly condense and efficiently prepare carbonates under key reaction conditions, achieving nearly 100% quantitative utilization of hydrocarbon groups.

[0006] In this application, we have achieved for the first time the green co-production of symmetrical carbonates (same hydrocarbon substituents) or asymmetrical carbonates (different hydrocarbon substituents) using hydrocarbon carbonate salts and aromatic methyl halogenated hydrocarbons as starting materials through a two-step reaction, with aromatic methyl alcohol as the by-product. The entire process does not involve traditional highly toxic raw materials such as phosgene, and also avoids the generation of organic waste. It has achieved the transformation from low-cost raw materials to high-value-added products, and has achieved the beneficial effects of cost reduction and efficiency improvement, which will help achieve the national "carbon peak" goal and is in line with the national green chemical development strategy. [Summary of the invention]

[0007] The present application found that, as shown in reaction formula (I), a monoalkyl carbonate salt A and a halogenated methyl aromatic hydrocarbon B generated by the addition of an alcohol or phenol R1OH and carbon dioxide CO2 undergo a nucleophilic substitution reaction under reaction conditions 1 to generate an intermediate aryl methyl carbonate C; then an alcoholysis reaction continues under reaction conditions 2 to generate a carbonate product D and an aryl methyl alcohol product E.

[0008] Reaction conditions 1 and conditions 2 are independent of each other and are at least one of solvent, temperature, pressure (or vacuum), and additives.

[0009]

[0010] Wherein R1, R2 or R3 are independently a branched or straight chain aliphatic hydrocarbon group containing 1 to 24 carbon atoms, or a (hetero) aromatic hydrocarbon group containing 4 to 24 carbon atoms; the hydrocarbon group can be 1 to 6 non-continuous oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms, epoxy groups, C=O bonds, or C=C bonds inserted or substituted. M is an n-valent metal cation, or a quaternary ammonium (phosphonium) salt cation. X is a halogen F, Cl, Br or I.

[0011] Preferably, R1, R2 or R3 are independently methyl, ethyl, divalent ethyl, divalent diethylene glycol alkyl, divalent triethylene glycol alkyl, divalent tetraethylene glycol alkyl, propyl, isopropyl, butyl, divalent butyl, isobutyl, tert-butyl, cyclohexyl, divalent hexyl, benzyl, phenyl, divalent phenyl, trivalent phenyl, divalent naphthyl, vinyl, biphenyl, naphthyl, divalent neopentyldialkyl, trivalent trimethylolpropane, tetravalent pentaerythritol, allyl, acryloyl, methacryloyl. M is preferably Na + , K + , Li + , Cs + , Rb + ,Mg 2+ , Ca 2+ , Zn 2+ , Ba 2+, Al 3+ , NH4 + , or organic quaternary ammonium ions (such as MeNH3 + ,Me4N + ,Et4N + ,Pr4N + ,Bu4N + , Et3MeN + wait).

[0012] n is an integer between 1 and 6; preferably, n is 1, 2, or 3.

[0013] The solvent is selected from at least one of substituted or unsubstituted aromatic hydrocarbons containing 1 to 24 carbon atoms, linear or branched aliphatic hydrocarbons, (sub)sulfones, amides, ethers, alcohols, esters, ketones, nitriles, carboxylic acids, water, amines, carbonates, ionic liquids, and supercritical carbon dioxide.

[0014] In some preferred embodiments of the present invention, the solvent is selected from acetonitrile, ethanol, butanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, dimethyl sulfone, benzyl sulfoxide, benzyl sulfone, cyclobutylene sulfoxide, cyclobutylene sulfone, trichlorosilane, dichloromethane, dichloroethane, dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, chloroform, carbon tetrachloride, benzene, toluene, xylene, trimethylbenzene, tetramethylbenzene, acetonitrile, ethylbenzene, diethylbenzene, chlorobenzene, dichlorobenzene, anisole, nitrobenzene At least one or more mixed solvents of heptane, hexane, petroleum ether, dioxane, tetrahydrofuran, methyltetrahydrofuran, methyl tert-butyl ether, ethylene glycol dimethyl ether, bis(ethylene glycol dimethyl ether), triethylene glycol dimethyl ether, propylene glycol methyl ether acetate, triethylamine, tributylamine, dimethylisopropylamine, pyridine, N,N-tetramethylethylenediamine, N-alkylmorpholine, N-alkylpyrrole, N,N-dimethylformamide, formylmorpholine, N,N-diethylformamide and N-methylpyrrolidone. In the present invention, the reaction can also be carried out by using only a small amount of or even no conventional "solvent" and by using solid-phase heating and / or grinding of the raw materials, and / or by promoting ultrasound and / or microwave irradiation, and by using supercritical carbon dioxide as the reaction medium.

[0015] The additive refers to a reaction accelerator, a synergist, a catalyst, an oxidant, an inhibitor, a reducing agent and / or a functional aid; based on the molar amount of the reaction raw material carbonate A, the halogenated methyl aromatic hydrocarbon B or the intermediate C, the amount of the additive used is a catalytic amount or an equivalent amount or an over equivalent amount (0-100 equivalents).

[0016] The temperature is 0°C-600°C. Preferably, the temperature is -20°C-200°C.

[0017] The pressure is 0.001atm-300atm; preferably, the pressure is 1atm-150atm.

[0018] Preferred conditions include two, three or four of the above four conditions (solvent, temperature, pressure or vacuum, and additives) at the same time.

[0019] The monoalkyl carbonate salt A is directly prepared by the addition of alcohol or phenol R1OH and carbon dioxide CO2. The A prepared in this way can be used directly or separated and purified before being applied to reaction formula (I); there is no special restriction. The intermediate aromatic methyl alkyl carbonate C prepared in this way can be used directly or separated and purified before being applied to reaction formula (II); there is no special restriction. The boiling points and polarities of the product carbonate D and aromatic methanol E are quite different, and they are easy to separate and purify. The remaining by-products are inorganic salts, which are also easy to separate and purify. The additives can be recycled.

[0020] A preferred preparation process for executing reaction formula (I) is to prepare a monoalkyl carbonate salt A by first reacting an alcohol or phenol R1OH, or its corresponding anionic base R1OM, with CO2; then, through a "one-pot" method, A first reacts with a halogenated methyl aromatic hydrocarbon B under the conditions 1 to undergo a nucleophilic substitution reaction to obtain a material containing an intermediate C, and then directly add an alcohol or phenol R3OH or its corresponding anionic base R3OM to undergo a decomposition reaction under the conditions 2 to simultaneously prepare a carbonate product D and an aromatic methyl alcohol product E.

[0021]

[0022] Preferred compounds of structure A are NaO-C(O)-OMe, LiO-C(O)-OMe, KO-C(O)-OMe, CsO-C(O)-OMe, NaO-C(O)-OEt, LiO-C(O)-OEt, KO-C(O)-OEt, CsO-C(O)-OEt, NaO-C(O)-OPh, LiO-C(O)-OPh, KO-C(O)-OPh, CsO-C(O)-OPh, Ca[OC(O)-OMe]2, Mg[OC(O)-OMe]2, Ba[OC(O)-OMe]2.

[0023] Preferred compounds of structure B are ArCH2Cl, ArCH2Br, ArCH2I.

[0024] Preferred R3OH is MeOH, EtOH, PrOH, BuOH, ethylene glycol, propylene glycol, butanediol.

[0025] Preferably, the method for executing the general reaction formula (I-II) is the following process (IIa-c):

[0026]

[0027] Through the technology disclosed in the present invention, the following exemplary but non-limiting symmetrical or asymmetrical carbonate compounds and the corresponding aromatic methyl alcohols can be prepared with high selectivity and high yield:

[0028]

[0029] The gist of the present invention is further explained below with reference to specific embodiments. [Specific implementation method]

[0030] Embodiment 1:

[0031]

[0032] On-site preparation of sodium methyl carbonate: refer to the operating procedures that have been reported and widely used.

[0033] Reaction of sodium methyl carbonate and benzyl chloride: Add sodium methyl carbonate (2g, 20.4mmol), benzyl chloride (2.15g, 17.0mmol), 1,2-dichlorobenzene (15mL) to the Schlenk reaction bottle and mix well. Insert the long needle of the CO2 balloon below the liquid surface, stir and bubble for a few minutes, and then seal. React in a 180℃ oil bath for 10 hours. After cooling to room temperature, filter, and then distill under reduced pressure to remove the solvent. The obtained crude product is directly used for the next reaction.

[0034] The crude product of the first step reaction was dissolved in methanol (10 mL), transferred to a Schlenk reaction bottle, and the catalyst sodium carbonate (0.18 g, 1.7 mmol) was added, and then sealed. The temperature was raised to 55°C for 12 hours. After cooling to room temperature, the bottle stopper was opened, biphenyl was added as an internal standard, and then sampling was performed to monitor the reaction. By gas chromatography (with biphenyl as an internal standard), it was found that the content of the target product dimethyl carbonate in the reaction solution was 1.19 grams (13.3 mmol), with a yield of 78%; the content of benzyl alcohol was 1.40 grams (12.9 mmol), with a yield of 76%.

[0035] Embodiment 2:

[0036]

[0037] On-site preparation of sodium ethyl carbonate: refer to the operating procedures that have been reported and widely used.

[0038] Reaction of sodium ethyl carbonate and benzyl bromide: Add sodium ethyl carbonate (4.57 g, 40.8 mmol), benzyl bromide (5.82 g, 34 mmol), acetonitrile (50 mL) to the reaction bottle and mix well. Insert the long needle of the CO2 balloon below the liquid surface, stir and bubble for a few minutes, then seal. Heat the oil bath to 85°C and reflux for 6 hours. After cooling to room temperature, filter, and then distill under reduced pressure to remove the solvent. The obtained crude product is directly used for the next reaction.

[0039] The crude product of the first step reaction was dissolved in methanol (50 mL), transferred to a sealed reactor, and a catalyst sodium hydroxide (0.136 g, 3.4 mmol) was added, and then sealed. The temperature was raised to 55°C for reaction for 3 hours. After cooling to room temperature, the reactor lid was opened, biphenyl was added as an internal standard, and then sampling was performed to monitor the reaction. By gas chromatography (with biphenyl as an internal standard), it was found that the content of the target product methyl ethyl carbonate in the reaction solution was 3.36 g (32.3 mmol), with a yield of 95%; the content of benzyl alcohol was 3.38 g (31.3 mmol), with a yield of 92%.

[0040] Embodiment 3:

[0041]

[0042] On-site preparation of tetrabutylammonium ethyl carbonate salt: refer to the operating procedures that have been reported and widely used.

[0043] Reaction of tetrabutylammonium ethyl carbonate and benzyl bromide: Add tetrabutylammonium ethyl carbonate (13.5 g, 40.8 mmol), benzyl bromide (5.82 g, 34 mmol), and chlorobenzene (50 mL) to the reaction bottle and mix well. Heat the oil bath to 80 ° C and react for 5 hours. After cooling to room temperature. Add ethanol (50 mL), transfer to a sealed reactor, add catalyst potassium carbonate (1.38 g, 10 mmol), and then seal. Heat to 65 ° C and react for 3 hours. After cooling to room temperature, open the lid of the reactor, add biphenyl as an internal standard, and then take samples to monitor the reaction. By gas chromatography (with biphenyl as an internal standard), it is found that the content of the target product diethyl carbonate in the reaction solution is 3.90 grams (33.0 mmol), with a yield of 97%; the content of p-methoxybenzyl alcohol is 4.51 grams (32.6 mmol), with a yield of 96%.

[0044] It should be emphasized that the above embodiments are merely illustrative and not restrictive. Based on the disclosure of this application, any adjustment or change in reaction conditions or parameters that may be commonly adopted by practitioners will not deviate from the gist of the present invention. The scope of protection of this patent shall be based on the relevant rights record items.

Claims

1. A new process for preparing carbonate esters with the participation of halogenated methyl aromatic hydrocarbons and a co-production technology. As shown in reaction formula (I), a monoalkyl carbonate salt A generated by the addition of alcohol or phenol R1OH and carbon dioxide CO2 and a halogenated methyl aromatic hydrocarbon B undergo a nucleophilic substitution reaction under reaction conditions 1 to prepare an intermediate aryl methyl alkyl carbonate ester C and a by-product salt MX; the intermediate C continues to undergo an alcoholysis reaction under reaction conditions 2 to prepare a carbonate ester product D and an aryl methyl alcohol product E. Wherein R1, R2 or R3 are independently a branched or straight chain aliphatic hydrocarbon group containing 1-24 carbon atoms, or a (hetero) aromatic hydrocarbon group containing 4-24 carbon atoms; the hydrocarbon group can be 1-6 non-continuous oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms, epoxy groups, C=O bonds, or C=C bonds inserted or substituted. M is an n-valent metal cation, or a quaternary ammonium (phosphonium) salt cation. n is an integer between 1 and 6. X is a halogen F, Cl, Br or I. The reaction conditions are independent of each other and are at least one of solvent, temperature, pressure (or vacuum), and additives.

2. According to claim (1), as shown in reaction formula (II), a preferred preparation process for executing reaction formula (I) is that a monoalkyl carbonate salt A is first prepared by addition of alcohol or phenol R1OH, or its corresponding anionic base R1OM, and CO2; then, by a "one-pot" method, A first reacts with a halogenated methyl aromatic hydrocarbon B under the conditions 1 to undergo a nucleophilic substitution reaction to obtain a material containing an intermediate C, and then alcohol or phenol R3OH or its corresponding anionic base R3OM is directly added to undergo a decomposition reaction under the conditions 2 to simultaneously prepare a carbonate product D and an aromatic methyl alcohol product E.

3. According to claim (1-2), the cation M in the carbonate structure A is preferably Na + , K + , Li + , Cs + , Rb + ,Mg 2+ , Ca 2+ , Zn 2+ , Ba 2+ , Al 3+ , NH 4+ , or organic ammonium ions (such as MeNH 3+ ,Me4N + ,Et4N + ,Pr4N + ,Bu4N + , Et3MeN + wait).

4. According to claim (1-2), the solvent is selected from at least one of substituted or unsubstituted aromatic hydrocarbons containing 1-24 carbon atoms, linear or branched aliphatic hydrocarbons, (sub)sulfones, amides, ethers, esters, alcohols, ketones, nitriles, carboxylic acids, water, amines, carbonates, ionic liquids, and supercritical carbon dioxide.

5. According to claim (1-2), the additive refers to a reaction accelerator, a synergist, a catalyst, an inhibitor, an oxidant, a reducing agent and / or a functional additive; based on the molar amount of the reaction raw materials, the amount of the additive used is a catalytic amount or an equivalent amount or an excess equivalent amount (0-100 equivalents).

6. According to claim (1-2), the temperature is 0°C-600°C. Preferably, the temperature is -20°C-200°C.

7. According to claim (1-2), the pressure is 0.001 atm-300 atm. Preferably, the pressure is 1 atm-150 atm.

8. According to claims (1-2), the preferred conditions include two, three or four of the above four conditions at the same time.

9. According to claim (1-2), the preferred method for carrying out reaction (I-II) is to carry out the following reaction (IIa-c) under the conditions:

10. According to claims (1, 2 and 7), the following compounds are prepared by the process disclosed in the present invention:

Images