Process for the co-production of methacrylate ester and methallyl alcohol

Abstract

The application relates to a method for co-producing methacrylate and methallyl alcohol, comprising the following steps: mixing methacrolein, a first catalyst and an aprotic nonpolar solvent to carry out a Chichibabin reaction to obtain a first reaction solution; the first catalyst comprises an aluminum alcoholate catalyst; mixing a fatty alcohol, a second catalyst and the first reaction solution to carry out an ester exchange reaction to prepare methacrylate and methallyl alcohol; the second catalyst comprises at least one of a titanate and an organotin. The method can co-produce methacrylate and methallyl alcohol in one pot, the yield is relatively high, by-products are relatively few, and the purity of the methacrylate and the methallyl alcohol is relatively high.

Description

Technical Field

[0001] This application relates to the field of synthetic technology, and in particular to a method for the co-production of methacrylate and methyl allyl alcohol. Background Technology

[0002] Methyl methacrylate (MMA) is an important chemical raw material and a monomer of polymethyl methacrylate. It is mainly used in the production of plexiglass (PMMA) and can also be copolymerized with other vinyl monomers to obtain products with different properties. It is widely used in plexiglass, coatings, lubricant additives, plastics, adhesives, resins, wood impregnating agents, motor coil impregnating agents, ion exchange resins, paper varnishes, textile printing and dyeing auxiliaries, leather treatment agents, printing and dyeing auxiliaries, and insulating potting materials.

[0003] Traditional MMA preparation processes include: the propionaldehyde route (BASF process), which boasts significant advantages in raw materials, high utilization rate, no wastewater discharge, and environmental friendliness; the isobutylene or tert-butanol route, also collectively known as the "isobutylene method," which offers significant advantages in raw materials, high utilization rate, no wastewater discharge, and environmental friendliness; however, both the BASF and isobutylene methods involve the use of precious metals such as palladium or gold catalysts, which have complex preparation processes and are expensive, resulting in high costs; the methyl propionate route (Alpha process), which offers milder operating conditions, high product yield, lower equipment investment and raw material costs, and easier scaling up of single units, but has a low methyl propionate conversion rate; and the acetone cyanohydrin route (ACH process), the most traditional and globally mainstream production process, which features a simple process, mature technology, and low investment, but the raw material, hydrogen cyanide, is highly toxic, and waste treatment is complex.

[0004] Methyl allyl alcohol (also known as 2-methyl allyl alcohol) is an important organic intermediate used in the synthesis of fragrances, resins, etc. Methyl allyl alcohol polyoxyethylene ether (HPEG) can be synthesized from methyl allyl alcohol and ethylene oxide, and is used in a new generation of high-performance concrete water-reducing agents. Methyl allyl alcohol can be used to synthesize methacrylic acid and its esters, and can also be combined with other organic acids to synthesize esters containing allyl groups, finding important applications in polymerization monomers and surfactants.

[0005] The traditional method for preparing methyl allyl alcohol uses 2-methylallyl chloride as a starting material and employs alkaline hydrolysis to produce methyl allyl alcohol, but this generates a large amount of byproduct ether, resulting in a low yield.

[0006] Therefore, it is necessary to improve traditional technologies. Summary of the Invention

[0007] Based on this, this application provides a method for co-producing methacrylate and methyl allyl alcohol with a high yield.

[0008] The technical solution to the above-mentioned technical problems in this application is as follows.

[0009] This application provides a method for the co-production of methacrylate and methyl allyl alcohol, comprising the following steps:

[0010] Methacrolein, a first catalyst, and an aprotic nonpolar solvent are mixed and subjected to a trishenko reaction to obtain a first reaction solution; the first catalyst includes aluminum alkoxide.

[0011] A fatty alcohol, a second catalyst, and the first reaction solution are mixed to carry out an ester exchange reaction to prepare methacrylate and methyl allyl alcohol; the second catalyst includes at least one of titanate and organotin.

[0012] In some embodiments, in the method for co-producing methacrylate and methyl allyl alcohol, the aprotic nonpolar solvent includes at least one of hydrocarbons, halogenated hydrocarbons, and ethers.

[0013] In some embodiments, in the method for co-producing methacrylate and methyl allyl alcohol, the aprotic nonpolar solvent includes at least one selected from toluene, xylene, cyclohexane, n-heptane, dichloromethane, dichloroethane, isopropyl ether, and butyl ether.

[0014] In some embodiments, in the method for co-producing methacrylate and methyl allyl alcohol, the mass ratio of the aprotic nonpolar solvent to the methacrolein is 0.1 to 0.8:1.

[0015] In some embodiments, in the method for co-producing methacrylate and methyl allyl alcohol, the titanate comprises at least one selected from tetrabutyl titanate, tetramethyl titanate, tetraethyl titanate, tetraisopropyl titanate, tetraisobutyl titanate, and tetraisooctyl titanate; and / or

[0016] The organotin comprises at least one of dibutyltin dilaurate, dibutyltin diacetate, dibutyltin oxide, and di(dodecyl sulfide)dibutyltin.

[0017] In some embodiments, in the method for co-producing methacrylate and methyl allyl alcohol, the molar ratio of the second catalyst to the methacrolein is 0.01 to 0.03:1.

[0018] In some embodiments, in the method for co-producing methacrylate and methyl allyl alcohol, the aluminum alkoxide catalyst comprises at least one selected from aluminum isopropoxide, aluminum sec-butoxide, aluminum tert-butoxide, and aluminum ethoxide; and / or

[0019] The molar ratio of the first catalyst to the methacrolein is 0.01 to 0.03:1.

[0020] In some embodiments, in the method for co-producing methacrylate and methyl allyl alcohol, the fatty alcohol includes at least one selected from methanol, ethanol, propanol, isopropanol, butanol, and isobutanol; and / or

[0021] The molar ratio of the fatty alcohol to the methacrolein is 1 to 4:1.

[0022] In some embodiments, in the method for co-producing methacrylate and methyl allyl alcohol, the temperature of the trishenko reaction is 20°C to 50°C, and the time is 20 h to 48 h; and / or

[0023] The Gishenko reaction was carried out under an inert atmosphere.

[0024] In some embodiments, in the method for co-producing methacrylate and methyl allyl alcohol, the trishenko reaction is carried out in the presence of a polymerization inhibitor.

[0025] In some embodiments, in the method for co-producing methacrylate and methacryl alcohol, the mass ratio of the polymerization inhibitor to the methacrylaldehyde is 0.0001 to 0.001:1; and / or

[0026] The polymerization inhibitor includes at least one of p-methoxyphenol and hydroquinone.

[0027] In some embodiments, in the method for co-producing methacrylate and methyl allyl alcohol, the transesterification reaction is carried out at a reflux temperature for 3 to 6 hours.

[0028] Compared with the prior art, the method for co-producing methacrylate and methyl allyl alcohol of this application has the following advantages:

[0029] The method for co-producing methacrylate and methyl allyl alcohol disclosed in this application involves a quasi-Syrenes reaction of methacrolein in the presence of an inexpensive and readily available first catalyst and aprotic nonpolar solvent. The conversion rate of methacrolein is high, and the selected methyl allyl methacrylate is highly selective. By employing a specific type of second catalyst, the first reaction solution obtained from the quasi-Syrenes reaction does not require post-treatment. The first reaction solution containing methyl allyl methacrylate is directly subjected to transesterification with a fatty alcohol in the presence of the specific type of second catalyst, thereby achieving a one-pot co-production of methacrylate and methyl allyl alcohol with high yield, few byproducts, and high purity of both methacrylate and methyl allyl alcohol. Detailed Implementation

[0030] The present application will be further described in detail below with reference to the embodiments and examples. It should be understood that these embodiments and examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the disclosure of the present application more thorough and comprehensive.

[0031] It should also be understood that this application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various alterations or modifications without departing from the spirit of this application, and the resulting equivalent forms also fall within the protection scope of this application. For example, features described or illustrated as part of one embodiment can be combined in a suitable manner in another embodiment to produce new embodiments. Furthermore, numerous specific details are set forth in the following description to provide a fuller understanding of this application; it should be understood that this application can be implemented without one or more of these details.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for descriptive purposes only and is not intended to be limiting of the application.

[0033] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0034] In this application, the terms "multiple", "various", "multiple times", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0035] The terms “combinations of,” “any combination of,” and “any combination of” used in this article include all suitable combinations of any two or more of the listed items.

[0036] In this document, the term "suitable" as used in "suitable combination", "suitable method", "any suitable method", etc., refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0037] In this document, terms such as "preferred," "better," "more suitable," and "ideal" are merely descriptions of more effective implementation methods or embodiments, and should be understood not to limit the scope of protection of this application. If multiple "preferred" terms appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "preferred" term shall be independent.

[0038] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0039] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0040] In this application, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0041] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0042] In this application, when numerical intervals (i.e., numerical ranges) are mentioned, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include numerical interval types such as percentage intervals, ratio intervals, and proportion intervals.

[0043] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0044] In this application, the terms "room temperature" or "normal temperature" generally refer to 4℃ to 35℃, for example, 20℃ ± 5℃. In some embodiments of this application, "room temperature" or "normal temperature" refers to 10℃ to 30℃. In some embodiments of this application, "room temperature" or "normal temperature" refers to 20℃ to 30℃.

[0045] In this application, if the unit of a data range is only followed by the right endpoint, it indicates that the units of the left and right endpoints are the same. For example, 3~5 h means that the units of the left endpoint "3" and the right endpoint "5" are both h (hours).

[0046] All references to documents mentioned in this application are incorporated herein by reference as if each document were individually incorporated by reference. Unless they conflict with the inventive purpose and / or technical solution of this application, all cited documents are incorporated herein by reference in their entirety and for all purposes. When citing documents in this application, the definitions of relevant technical features, terms, nouns, phrases, etc., are also incorporated herein by reference. When citing documents in this application, examples and preferred embodiments of the cited technical features may also be incorporated herein by reference, but only to the extent that they enable the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, this application shall prevail or modifications shall be made adaptably to the description in this application.

[0047] The mass or weight of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship of mass or weight between the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass or weight mentioned in the embodiments of this application can be units known in the chemical industry, such as μg, mg, g, and kg.

[0048] The Tishchenko reaction is an organic reaction in which an aldehyde without α-active hydrogen undergoes disproportionation to form an ester in the presence of an alkoxide (such as aluminum alkoxide).

[0049]

[0050] Ester exchange is the reaction in which an ester reacts with an alcohol under the catalysis of an acid or a base to form a new ester and a new alcohol; it is also known as the alcoholysis of an ester.

[0051]

[0052] One embodiment of this application provides a method for co-producing methacrylate and methyl allyl alcohol, comprising the following steps:

[0053] Step S10: Methacrolein, the first catalyst, and an aprotic nonpolar solvent are mixed and subjected to a trishenko reaction to obtain a first reaction solution; the first catalyst includes aluminum alkoxide.

[0054] Methacrolein undergoes a trishenko reaction in the presence of an inexpensive and readily available first catalyst and an aprotic nonpolar solvent, resulting in a high conversion rate of methacrolein and a high selectivity for the generated methyl allyl methacrylate.

[0055] In some of these examples, in step S10, the aprotic nonpolar solvent includes at least one of hydrocarbons, haloalkanes, and ethers.

[0056] In some of these examples, in step S10, the hydrocarbon aprotic nonpolar solvent includes, but is not limited to, at least one of alkanes and aromatic hydrocarbons; further, the halogenated hydrocarbons include, but are not limited to, halogenated alkanes.

[0057] In some of these examples, in step S10, the aprotic nonpolar solvent includes at least one of toluene, xylene, cyclohexane, n-heptane, dichloromethane, dichloroethane, isopropyl ether, and butyl ether.

[0058] In some examples, in step S10, the mass ratio of the aprotic nonpolar solvent to methacrolein is 0.1 to 0.8:1.

[0059] It is understood that the mass ratio of the nonprotic nonpolar solvent to methacrolein includes, but is not limited to, 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, and 0.8:1; in some examples, it can be any two of these point values ​​as the end values, and the same applies below.

[0060] Optionally, in step S10, the mass ratio of the aprotic nonpolar solvent to methacrolein is 0.3~0.8:1.

[0061] In some of these examples, in step S10, the aluminum alkoxide catalyst includes at least one of aluminum isopropoxide, aluminum sec-butoxide, aluminum tert-butoxide, and aluminum ethoxide.

[0062] In some of these examples, in step S10, the molar ratio of the first catalyst to methacrolein is 0.01 to 0.03:1.

[0063] It is understood that the molar ratio of the first catalyst to methacrolein includes, but is not limited to, 0.01:1, 0.012:1, 0.015:1, 0.018:1, 0.02:1, 0.022:1, 0.025:1, 0.028:1, and 0.03:1.

[0064] Optionally, in step S10, the molar ratio of the first catalyst to methacrolein is 0.02~0.03:1.

[0065] In some of these examples, in step S10, the temperature of the Jixianke reaction is 20°C to 50°C, and the time is 20 h to 48 h.

[0066] It is understandable that the temperature of the Ji Xianke reaction includes, but is not limited to, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, and 50℃, and the time includes, but is not limited to, 20 h, 24 h, 28 h, 30 h, 34 h, 38 h, 40 h, 44 h, 45 h, and 48 h.

[0067] Optionally, in step S10, the temperature of the zissenk reaction is 25°C to 40°C; further, the temperature of the zissenk reaction is 30°C to 35°C.

[0068] Optionally, in step S10, the reaction time of Ji Xianke is 20 h to 45 h.

[0069] In some of these examples, in step S10, the Tishchenko reaction is carried out under an inert atmosphere.

[0070] It is understood that inert atmospheres include, but are not limited to, nitrogen and inert gases; furthermore, inert gases include argon, etc.

[0071] In some of these examples, in step S10, the gisenco reaction is carried out in the presence of a polymerization inhibitor.

[0072] In some of these examples, in step S10, the mass ratio of the polymerization inhibitor to methacrolein is 0.0001 to 0.001:1.

[0073] It is understood that the mass ratio of the polymerization inhibitor to methacrolein includes, but is not limited to, 0.0001:1, 0.0002:1, 0.0003:1, 0.0004:1, 0.0005:1, 0.0006:1, 0.0007:1, 0.0008:1, 0.0009:1, and 0.001:1.

[0074] Optionally, in step S10, the mass ratio of the polymerization inhibitor to methacrolein is 0.0003~0.008:1.

[0075] In some of these examples, in step S10, the polymerization inhibitor includes at least one of p-methoxyphenol and hydroquinone.

[0076] In some of these examples, step S10 includes the following steps:

[0077] A catalyst solution is prepared by mixing the catalyst with an aprotic, nonpolar solvent.

[0078] Methacrolein and a polymerization inhibitor are mixed and added dropwise to a catalyst solution to carry out the trishenko reaction.

[0079] Step S20: Mix fatty alcohol, second catalyst and first reaction solution to carry out transesterification reaction to prepare methacrylate and methyl allyl alcohol; the second catalyst includes at least one of titanate and organotin.

[0080] The reaction routes for steps S10 and S20 are as follows:

[0081]

[0082] By employing a specific type of second catalyst, the first reaction solution obtained from the S10 terephthalic reaction can be directly subjected to transesterification with a fatty alcohol under the action of this specific type of second catalyst without post-treatment. This achieves a one-pot co-production of methacrylate and methylallyl alcohol with high yield, few byproducts, and high purity of both methacrylate and methylallyl alcohol.

[0083] The one-pot process for co-producing methacrylates and methyl allyl alcohol reduces the need for intermediate separation and purification steps, thereby lowering costs and time. Furthermore, the one-pot process offers significant environmental advantages, reducing chemical reaction steps and waste generation, aligning with green chemistry principles.

[0084] Furthermore, there is no step between steps S10 and S20 to post-process the first reaction solution obtained from the siphon reaction in step S10.

[0085] Studies have found that directly subjecting the first reaction solution containing methyl allyl methacrylate and a fatty alcohol to a transesterification reaction in the presence of phosphoric acid results in a low conversion rate of methyl allyl methacrylate, leading to low yields of both methacrylate and methyl allyl alcohol. Analysis suggests this is because step S10 (the Tristanko reaction) uses an alkaline catalyst, while step S20 in the one-pot process uses an acidic catalyst. The phosphoric acid is consumed by the aluminum alkoxide catalyst in the Tristanko reaction, generating aluminum phosphate, which loses its catalytic effect, thus reducing the degree of reaction progression.

[0086] In some of these examples, in step S20, the titanate includes at least one of tetrabutyl titanate, tetramethyl titanate, tetraethyl titanate, tetraisopropyl titanate, tetraisobutyl titanate, and tetraisooctyl titanate.

[0087] In some of these examples, in step S20, the organotin comprises at least one of dibutyltin dilaurate, dibutyltin diacetate, dibutyltin oxide, and di(dodecyl sulfide)dibutyltin.

[0088] Optionally, the second catalyst includes at least one of tetrabutyl titanate and dibutyltin dilaurate.

[0089] In some of these examples, in step S20, the molar ratio of the second catalyst to methacrolein is 0.01 to 0.03:1.

[0090] It is understood that the molar ratio of the second catalyst to methacrolein includes, but is not limited to, 0.01:1, 0.012:1, 0.015:1, 0.018:1, 0.02:1, 0.022:1, 0.025:1, 0.028:1, and 0.03:1.

[0091] Optionally, the molar ratio of the second catalyst to methacrolein is 0.01 to 0.02:1.

[0092] In some of these examples, in step S20, the fatty alcohol includes at least one of methanol, ethanol, propanol, isopropanol, butanol, and isobutanol.

[0093] In some of these examples, in step S20, the molar ratio of fatty alcohol to methacrolein is 1 to 4:1.

[0094] It is understood that the molar ratio of fatty alcohol to methacrolein includes, but is not limited to, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, and 4:1.

[0095] Optionally, the molar ratio of fatty alcohol to methacrolein is 2 to 4:1.

[0096] In some of these examples, in step S20, the transesterification reaction is carried out at a reflux temperature for 3 to 6 hours.

[0097] It can be understood that reflux temperature refers to the temperature of the reaction system maintained during a chemical reaction by continuously refluxing certain reactants or products back into the reactor. Furthermore, reflux times include, but are not limited to, 3 h, 4 h, 5 h, and 6 h.

[0098] In some of these examples, in step S20, the transesterification reaction is carried out under an inert atmosphere.

[0099] It is understood that inert atmospheres include, but are not limited to, nitrogen and inert gases; furthermore, inert gases include argon, etc.

[0100] In some of these examples, after the transesterification reaction in step S20, the reaction solution is distilled to obtain methacrylate and methyl allyl alcohol.

[0101] The method for co-producing methacrylate and methyl allyl alcohol in this application does not require the use of precious metal palladium or gold catalysts, nor does it require the use of highly toxic hydrogen cyanide. It has high atom economy, low cost, mild reaction conditions, and a clean and green process.

[0102] The present application will be described in further detail below with reference to specific embodiments, but the embodiments of the present application are not limited thereto.

[0103] Example 1

[0104] Ji Xianke reaction: Under nitrogen protection, 30 mL of xylene and 4.1 g (0.02 mol) of aluminum triisopropoxide were added to a 250 mL three-necked flask. After stirring and dissolving, 70 g of methacrolein (1 mol) and 0.036 g of p-methoxyphenol (mass ratio of polymerization inhibitor to methacrolein was 0.0005:1) solution were added dropwise from a constant pressure dropping funnel. The addition was completed in 2 hours. The reaction temperature was controlled at 30℃~35℃ and kept at this temperature for 30 hours. Gas phase analysis showed that the mass content of methacrolein was 0.25%, and the reaction solution of methyl allyl methacrylate was obtained.

[0105] Transesterification reaction: 96 g of methanol (3 mol) and 6.32 g of dibutyltin dilaurate (the molar ratio of the second catalyst to methacrolein was 0.01:1) were added to the above methyl allyl methacrylate reaction solution. The mixture was heated to reflux with methanol and reacted for 5 hours. Gas phase analysis showed that the mass content of methyl allyl methacrylate was 0.35%. By distillation, 42.9 g of methyl methacrylate with a purity of 99.50% and a molar yield of 42.9% were obtained, along with 34.2 g of methyl allyl alcohol with a purity of 99.6% and a molar yield of 47.5%.

[0106] Molar yield = (mass of product ÷ molar mass of product) / molar amount of raw material × 100%; for example, the molar yield of methyl methacrylate in Example 1 = (42.9 g ÷ 100.12 g / mol) / 1 mol × 100% = 42.9%.

[0107] Theoretically, 2 mol of methacrolein can generate 1 mol of methyl methacrylate and 1 mol of methyl allyl alcohol, so the theoretical yield of methyl methacrylate and methyl allyl alcohol is 50%.

[0108] Example 2

[0109] Ji Xianke reaction: Under nitrogen protection, 30 mL of xylene and 4.1 g (0.02 mol) of aluminum triisopropoxide were added to a 250 mL three-necked flask. After stirring and dissolving, 70 g of methacrolein (1 mol) and 0.036 g of p-methoxyphenol solution were added dropwise from a constant pressure dropping funnel. The addition was completed in 2 hours. The reaction temperature was controlled at 30-35℃ and kept at this temperature for 30 hours. Gas phase analysis showed that the mass content of methacrolein was 0.25%, and the reaction solution of methyl allyl methacrylate was obtained.

[0110] Transesterification reaction: 180 g of n-propanol (3 mol) and 6.32 g of dibutyltin dilaurate were added to the above methyl allyl methacrylate reaction solution. The mixture was heated to reflux with methanol and reacted for 8 hours. Gas phase analysis showed that the mass content of methyl allyl methacrylate was 0.35%. By distillation, 53.2 g of propyl methacrylate with a purity of 99.60% and a molar yield of 41.5% were obtained, along with 34.0 g of methyl allyl alcohol with a purity of 99.6% and a molar yield of 47.2%.

[0111] Example 3

[0112] Ji Xianke reaction: Under nitrogen protection, 30 mL of xylene and 6.2 g (0.03 mol) of aluminum triisopropoxide were added to a 250 mL three-necked flask. After stirring and dissolving, 70 g of methacrolein (1 mol) and 0.036 g of p-methoxyphenol solution were added dropwise from a constant pressure dropping funnel. The addition was completed in 2 hours. The reaction temperature was controlled at 30-35℃ and kept at this temperature for 20 hours. Gas phase analysis showed that the mass content of methacrolein was 0.20%, and the reaction solution of methyl allyl methacrylate was obtained.

[0113] Transesterification reaction: 96 g of methanol (3 mol) and 6.32 g of dibutyltin dilaurate were added to the above methyl allyl methacrylate reaction solution. The mixture was heated to reflux with methanol and reacted for 5 hours. Gas phase analysis showed that the mass content of methyl allyl methacrylate was 0.35%. By distillation, 40.5 g of methyl methacrylate with a purity of 99.50% and a molar yield of 40.5% was obtained; 35.9 g of methyl allyl alcohol with a purity of 99.6% and a molar yield of 49.8% was also obtained.

[0114] Example 4

[0115] Ji Xianke reaction: Under nitrogen protection, 40 mL of dichloroethane and 6.2 g (0.02 mol) of aluminum triisopropoxide were added to a 250 mL three-necked flask. After stirring and dissolving, 70 g of methacrolein (1 mol) and 0.036 g of p-methoxyphenol solution were added dropwise from a constant pressure dropping funnel. The addition was completed in 2 hours. The reaction temperature was controlled at 30-35℃ and kept at this temperature for 45 hours. Gas phase analysis showed that the mass content of methacrolein was 0.50%, and the reaction solution of methyl allyl methacrylate was obtained.

[0116] Transesterification reaction: 96 g of methanol (3 mol) and 6.32 g of dibutyltin dilaurate were added to the above methyl allyl methacrylate reaction solution. The mixture was heated to reflux with methanol and reacted for 6 hours. Gas phase analysis showed that the mass content of methyl allyl methacrylate was 0.45%. By distillation, 41.5 g of methyl methacrylate with a purity of 99.50% and a molar yield of 41.5% was obtained; 35.0 g of methyl allyl alcohol with a purity of 99.6% and a molar yield of 48.6% was also obtained.

[0117] Example 5

[0118] Ji Xianke reaction: Under nitrogen protection, 30 mL of xylene and 4.1 g (0.02 mol) of aluminum triisopropoxide were added to a 250 mL three-necked flask. After stirring and dissolving, 70 g of methacrolein (1 mol) and 0.03 g of hydroquinone solution were added dropwise from a constant pressure dropping funnel. The addition was completed in 2 hours. The reaction temperature was controlled at 30-35℃ and kept at this temperature for 30 hours. Gas phase analysis showed that the mass content of methacrolein was 0.45%, and the reaction solution of methyl allyl methacrylate was obtained.

[0119] Transesterification reaction: 96 g of methanol (3 mol) and 6.32 g of dibutyltin dilaurate were added to the above methyl allyl methacrylate reaction solution. The mixture was heated to reflux with methanol and reacted for 5.5 hours. Gas phase analysis showed that the mass content of methyl allyl methacrylate was 0.45%. By distillation, 42.2 g of methyl methacrylate with a purity of 99.50% and a molar yield of 42.2% were obtained, along with 33.0 g of methyl allyl alcohol with a purity of 99.6% and a molar yield of 45.8%.

[0120] Example 6

[0121] Ji Xianke reaction: Under nitrogen protection, 30 mL of xylene and 4.1 g (0.02 mol) of aluminum triisopropoxide were added to a 250 mL three-necked flask. After stirring and dissolving, 70 g of methacrolein (1 mol) and 0.036 g of p-methoxyphenol solution were added dropwise from a constant pressure dropping funnel. The addition was completed in 2 hours. The reaction temperature was controlled at 40-45℃ and kept at this temperature for 25 hours. Gas phase analysis showed that the mass content of methacrolein was 0.25%, and the reaction solution of methyl allyl methacrylate was obtained.

[0122] Transesterification reaction: 96 g of methanol (3 mol) and 3.40 g of tetrabutyl titanate were added to the above methyl allyl methacrylate reaction solution, and the mixture was heated to reflux with methanol for 8 hours. Gas phase analysis showed that the mass content of methyl allyl methacrylate was 0.55%. By distillation, 40.9 g of methyl methacrylate with a purity of 99.50% and a molar yield of 40.9% was obtained; 34.8 g of methyl allyl alcohol with a purity of 99.6% and a molar yield of 48.3% was also obtained.

[0123] Comparative Example 1

[0124] The reaction was basically the same as in Example 1, except that xylene in the Giscard reaction was replaced with an equal volume of the polar solvent ethyl acetate. After the Giscard reaction was kept at a constant temperature for 30 h, the reaction system was turbid, and gas phase analysis showed that methacrolein was basically not converted.

[0125] Comparative Example 2

[0126] The process was essentially the same as in Example 1, except that dibutyltin dilaurate was replaced with an equal mass of phosphoric acid in the transesterification reaction. In the transesterification reaction, the mixture was heated to reflux with methanol and reacted for 8 hours. The reaction system was turbid, and gas chromatography analysis revealed only small amounts of methyl methacrylate and methyl allyl alcohol in the reaction solution; most of the methyl allyl methacrylate remained unconverted.

[0127] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0128] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A method for co-producing methacrylate and methyl allyl alcohol, characterized in that, Includes the following steps: Methacrolein, a first catalyst, and a solvent are mixed and subjected to a trishenko reaction to obtain a first reaction solution; the first catalyst includes an aluminum alkoxide catalyst; the solvent includes at least one of xylene and dichloroethane; the aluminum alkoxide catalyst includes aluminum isopropoxide; the mass ratio of the solvent to the methacrolein is 0.1~0.8:1; A fatty alcohol, a second catalyst, and the first reaction solution are mixed to carry out a transesterification reaction to prepare methacrylate and methyl allyl alcohol; the second catalyst includes at least one of titanate and organotin; The titanate includes at least one of tetrabutyl titanate, tetramethyl titanate, tetraethyl titanate, tetraisopropyl titanate, and tetraisooctyl titanate. The organotin includes dibutyltin dilaurate; The fatty alcohol includes at least one of methanol, ethanol, propanol, and butanol.

2. The method for co-producing methacrylate and methyl allyl alcohol as described in claim 1, characterized in that, The mass ratio of the solvent to the methacrolein is 0.3~0.8:

1.

3. The method for co-producing methacrylate and methyl allyl alcohol as described in claim 1, characterized in that, The titanate includes tetrabutyl titanate.

4. The method for co-producing methacrylate and methyl allyl alcohol as described in claim 1, characterized in that, The molar ratio of the second catalyst to the methacrolein is 0.01 to 0.03:

1.

5. The method for co-producing methacrylate and methyl allyl alcohol as described in any one of claims 1 to 4, characterized in that, The molar ratio of the first catalyst to the methacrolein is 0.01~0.03:1; and / or The molar ratio of the fatty alcohol to the methacrolein is 1 to 4:

1.

6. The method for co-producing methacrylate and methyl allyl alcohol as described in any one of claims 1 to 4, characterized in that, The temperature of the Jixianke reaction is 20℃~50℃, and the time is 20 h~48 h; and / or The kissenko reaction is carried out under an inert atmosphere; and / or The tristanko reaction is carried out in the presence of a polymerization inhibitor.

7. The method for co-producing methacrylate and methyl allyl alcohol as described in claim 6, characterized in that, The mass ratio of the polymerization inhibitor to the methacrolein is 0.0001 to 0.001:1; and / or The polymerization inhibitor includes at least one of p-methoxyphenol and hydroquinone.

8. The method for co-producing methacrylate and methyl allyl alcohol according to any one of claims 1 to 4 and 7, characterized in that, The transesterification reaction was carried out at reflux temperature for 3 to 6 hours.

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