Preparation method of N-alkenyl amide compound

Abstract

The invention relates to the technical field of oilfield exploitation, and discloses a preparation method of an N-alkenyl amide compound, the ester compound prepared by the method can significantly reduce the cracking temperature, shorten the cracking reaction time and achieve the effects of saving energy consumption and reducing cost in the cracking process, the cracking reaction conditions are mild, and the method is suitable for industrial production. According to the present invention, the method has characteristics of low reaction equipment requirement, low corrosion and high production process safety, and the cracking temperature of the method is less than 100 DEG C so as to significantly inhibit the decomposition of N-alkenyl amide during the cracking process, and improve the yield and the purity of the product.

Description

Technical Field

[0001] The present invention belongs to the technical field of oilfield exploitation, and specifically relates to a method for preparing N-alkenylamide compounds. Background Art

[0002] N-alkenylamide compounds are key raw materials for producing important monomers and polymers containing amine groups and amino compounds. The alkenyl group in this type of molecule is directly connected to the N atom, forming a p-π conjugation, which causes the electron cloud density of the double bond to be higher than that of simple alkenes. However, due to the presence of a carbonyl group at the adjacent position, the double bond has less electron content compared to simple enamines and has higher polymerization activity.

[0003] The polymerization product of N-vinylamide can be hydrolyzed to form polyvinylamine, which has a high unit cationic charge density and is currently widely used in the paper chemical and water treatment markets. At the same time, due to the low cytotoxicity of this polymer, it is a perfect substitute for polyethyleneimine, polyvinylpyrrolidone, etc. in the biomedical field.

[0004] Currently, companies worldwide that master the N-vinylamide synthesis process include BASF in Germany, Mitsubishi in Japan, and Showa Denko in Japan. BASF in Germany uses hydrocyanic acid and acetaldehyde to react to prepare lactonitrile, which reacts with formamide by substitution and dehydration to form N-(α-cyanoethyl)formamide, and then undergoes high-temperature pyrolysis to obtain N-vinylformamide. The raw material hydrocyanic acid used in this method has the disadvantages of high toxicity and easy explosion, resulting in poor safety of this method.

[0005]

[0006] Mitsubishi in Japan uses acetaldehyde and formamide as raw materials, which react under alkaline conditions to form N-(α-hydroxyethyl)formamide. The latter reacts with methanol by etherification under acidic conditions to obtain N-(α-methoxyethyl)formamide, and then methanol is removed by thermal decomposition to obtain N-vinylformamide. This process produces a large amount of waste acid and waste alkali liquor, and the reaction intermediate has poor stability, resulting in strict reaction conditions and high costs.

[0007]

[0008] In addition to the above processes, Showa Denko in Japan has disclosed a method for preparing N-vinylcarboxylic acid amide, which uses an acyl compound and 2-oxoethylamine to react to form N-(2-oxoethyl)carboxylic acid amide, and then undergoes thermal decomposition in the presence of a solid catalyst to obtain N-vinylcarboxylic acid amide.

[0009]

[0010] Existing methods for synthesizing N-vinylamides all involve a cracking process, and the cracking temperature is usually not lower than 200°C. According to literature reports, N-vinylformamide has poor thermal stability and is prone to deterioration under high-temperature conditions, resulting in a low reaction yield and difficult separation. Summary of the Invention

[0011] The object of the present invention is to overcome the problems of high cracking temperature and possible product deterioration and difficult separation existing in the prior art, and to provide a method for preparing N-alkenylamide compounds.

[0012] To achieve the above object, the present invention provides a method for preparing N-alkenylamide compounds, which is characterized in that the preparation method includes:

[0013] (1) Optionally, mixing an alkanolamine represented by formula (I) with an acyl compound represented by formula (II) for an amidation reaction to obtain N-(2-hydroxyalkyl)amide;

[0014]

[0015] wherein, R 1 is selected from a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R 2 and R 3 are each independently selected from a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R 4 is selected from chlorine, bromine or an alkoxy group having 1 to 5 carbon atoms;

[0016] (2) Contacting N-(2-hydroxyalkyl)amide with a benzene derivative represented by formula (III) for an esterification reaction;

[0017]

[0018] wherein, R 5 is selected from an electron-withdrawing group having 1 to 5 carbon atoms; R 6 is selected from chlorine, bromine, a hydroxyl group or an alkoxy group having 1 to 5 carbon atoms;

[0019] (3) Subjecting the product of step (2) to a cracking reaction.

[0020] By the above technical solution, the present invention can at least obtain the following beneficial effects:

[0021] (1) The ester compound prepared by the present invention can significantly reduce the cracking temperature and shorten the cracking reaction time during the cracking process, achieving the effects of saving energy consumption and reducing costs;

[0022] (2) The cracking reaction conditions of the present invention are mild, the requirements for reaction equipment are low and the corrosion is small, and the production process has high safety;

[0023] (3) N-alkenylamides have poor thermal stability and will decompose under high-temperature cracking conditions. The cracking temperature of this method can be lower than 100 °C, which can significantly inhibit the decomposition of N-alkenylamides during the cracking process and improve the yield and purity of the product;

[0024] (4) In a preferred embodiment of the present invention, by recovering the alcohol in the esterification reaction product and the organic acid in the cracking product, and contacting the recovered organic acid with the alcohol for reaction, the raw material benzene-based derivative is recovered, significantly reducing the process cost, reusing the waste alcohol and organic acid, and reducing pollution. Detailed implementation mode

[0025] The endpoints and any values within the ranges disclosed herein are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoints of each range, between the endpoints of each range, between the endpoints of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0026] The present invention provides a method for preparing N-alkenylamide compounds, characterized in that the preparation method includes:

[0027] (1) Optionally, mixing an alkanolamine represented by formula (I) with at least one acyl compound represented by formula (II) for an amidation reaction to obtain N-(2-hydroxyalkyl)amide;

[0028]

[0029] Wherein, R 1 is selected from a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R 2 and R 3 are each independently selected from a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R 4 is selected from chlorine, bromine or an alkoxy group having 1 to 5 carbon atoms;

[0030] (2) Contacting N-(2-hydroxyalkyl)amide with a benzene-based derivative represented by formula (III) for an esterification reaction;

[0031]

[0032] Wherein, R 5 is selected from an electron-withdrawing group having 1 to 5 carbon atoms; R 6 is selected from chlorine, bromine, a hydroxyl group or an alkoxy group having 1 to 5 carbon atoms;

[0033] (3) Subjecting the product of step (2) to a cracking reaction.

[0034] The reaction process of the present invention is as follows:

[0035]

[0036] In the present invention, in the described preparation method, esterification is carried out using the benzene-based derivative described in the present application, and the obtained ester compound can significantly reduce the subsequent cracking reaction temperature from the conventional 300 - 500 °C to 10 - 150 °C, greatly shortening the reaction time and reducing the production energy consumption at the same time.

[0037] In the present invention, in the described preparation method, step (1) is an optional step. N-(2-hydroxyalkyl)amide can be prepared through step (1), and N-(2-hydroxyalkyl)amide can also be obtained through a commercially available route.

[0038] In the present invention, there is no particular limitation on the amounts of the respective raw materials in the preparation process of the compound. Preferably, the molar ratio of the alkanolamine to the acyl compound can be 1:0.8 - 10, and the molar ratio of the N-(2-hydroxyalkyl)amide to the benzene-based derivative can be 1:0.5 - 2.5; more preferably, the molar ratio of the alkanolamine to the acyl compound can be 1:1 - 5, and the molar ratio of the N-(2-hydroxyalkyl)amide to the benzene-based derivative can be 1:0.55 - 1.4.

[0039] In the present invention, the alkanolamine only needs to satisfy the structure of formula (I). Preferably, the alkanolamine can be selected from at least one of 2-hydroxyethylamine, 2-amino-1-propanol, 2-amino-1-butanol, 2-amino-1-pentanol, 2-amino-3-methyl-1-butanol, 2-amino-1-hexanol, 2-amino-4-methyl-1-pentanol, 2-amino-3-methyl-1-pentanol, 2-amino-1-heptanol, 2-amino-5-methyl-1-hexanol, N-methyl-2-hydroxyethylamine, N-ethyl-2-hydroxyethylamine, N-propyl-2-hydroxyethylamine, N-isopropyl-2-hydroxyethylamine, N-butyl-2-hydroxyethylamine, N-isobutyl-2-hydroxyethylamine, N-pentyl-2-hydroxyethylamine, N-((3-methylbutyl)amino)ethanol, N-((2-methylbutyl)amino)ethanol, 2-methylamino-1-propanol, 2-methylamino-1-butanol, 2-methylamino-1-pentanol, 2-methylamino-1-hexanol or 2-methylamino-1-heptanol; more preferably, the alkanolamine can be selected from at least one of 2-hydroxyethylamine, N-methyl-2-hydroxyethylamine, N-ethyl-2-hydroxyethylamine, N-propyl-2-hydroxyethylamine, 2-amino-1-propanol, 2-amino-1-butanol, 2-amino-1-pentanol or 2-methylamino-1-propanol.

[0040] In the present invention, the acyl compound only needs to satisfy the structure of formula (II). Preferably, the acyl compound may be selected from at least one of formyl chloride, acetyl chloride, propionyl chloride, butyryl chloride, valeryl chloride, formyl bromide, acetyl bromide, propionyl bromide, butyryl bromide, valeryl bromide, methyl formate, ethyl formate, propyl formate, butyl formate, pentyl formate, ethyl acetate, ethyl acetate, propyl acetate, butyl acetate, pentyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, pentyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, pentyl butyrate, methyl valerate, ethyl valerate, propyl valerate, butyl valerate, pentyl valerate, methyl hexanoate, ethyl hexanoate, propyl hexanoate, butyl hexanoate or pentyl hexanoate; More preferably, the acyl compound may be selected from at least one of formyl chloride, acetyl chloride, propionyl chloride, methyl formate, ethyl formate, ethyl acetate or ethyl propionate.

[0041] In the present invention, the benzene derivative only needs to satisfy the structure of formula (III). Preferably, the benzene derivative may be selected from at least one of phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, p-trifluoromethylbenzoyl chloride, p-cyanobenzoyl chloride, m-trifluoromethylbenzoyl chloride, m-cyanobenzoyl chloride, o-trifluoromethylbenzoyl chloride, o-cyanobenzoyl chloride, phthaloyl bromide, isophthaloyl bromide, terephthaloyl bromide, p-trifluoromethylbenzoyl bromide, p-cyanobenzoyl bromide, m-trifluoromethylbenzoyl bromide, m-cyanobenzoyl bromide, o-trifluoromethylbenzoyl bromide, o-cyanobenzoyl bromide, phthalic acid, isophthalic acid, terephthalic acid, o-trifluoromethylbenzoic acid, o-cyanobenzoic acid, m-trifluoromethylbenzoic acid, m-cyanobenzoic acid, p-trifluoromethylbenzoic acid, p-cyanobenzoic acid, methyl phthalate, methyl isophthalate, methyl terephthalate, methyl p-trifluoromethylbenzoate, methyl p-cyanobenzoate, methyl m-trifluoromethylbenzoate, methyl m-cyanobenzoate, methyl o-trifluoromethylbenzoate, methyl o-cyanobenzoate, ethyl phthalate, ethyl isophthalate, ethyl terephthalate, ethyl p-trifluoromethylbenzoate, ethyl p-cyanobenzoate, ethyl m-trifluoromethylbenzoate, ethyl m-cyanobenzoate, ethyl o-trifluoromethylbenzoate, ethyl o-cyanobenzoate, propyl isophthalate, propyl terephthalate, propyl p-trifluoromethylbenzoate, propyl p-cyanobenzoate, propyl m-trifluoromethylbenzoate, propyl m-cyanobenzoate, propyl o-trifluoromethylbenzoate, propyl o-cyanobenzoate, butyl isophthalate, butyl terephthalate, butyl p-trifluoromethylbenzoate, butyl p-cyanobenzoate, butyl m-trifluoromethylbenzoate, butyl m-cyanobenzoate, amyl isophthalate, amyl terephthalate, amyl p-trifluoromethylbenzoate, amyl p-cyanobenzoate, amyl m-trifluoromethylbenzoate, amyl m-cyanobenzoate, trimesoyl chloride, trimesoyl bromide, trimesic acid, methyl trimesate, isophthaloyl chloride, isophthaloyl bromide, isophthalic acid, methyl isophthalate, trimellitic anhydride, trimellitic chloride, trimellitic bromide, trimellitic acid, methyl trimellitate, mellitic anhydride, mellitic chloride, mellitic bromide, mellitic acid or methyl mellitate; More preferably, the benzene derivative may be selected from at least one of isophthaloyl chloride, terephthaloyl chloride, p-trifluoromethylbenzoyl chloride, isophthalic acid, terephthalic acid, p-trifluoromethylbenzoic acid, p-cyanobenzoic acid, methyl isophthalate, methyl terephthalate, methyl p-trifluoromethylbenzoate, methyl p-cyanobenzoate, ethyl isophthalate, ethyl terephthalate, ethyl p-trifluoromethylbenzoate, ethyl p-cyanobenzoate, mellitic anhydride or mellitic acid.

[0042] In the present invention, there are no particular requirements for the conditions of the amidation reaction, as long as the raw materials can react. Preferably, the conditions of the amidation reaction may include: a reaction temperature of 0 - 120 °C and a reaction time of 1 - 10 h; more preferably, the conditions of the amidation reaction may include: a reaction temperature of 0 - 90 °C and a reaction time of 2 - 8 h.

[0043] In the present invention, there are no particular requirements for the conditions of the amidation reaction. Preferably, the conditions of the esterification reaction may include: a reaction temperature of 0 - 150 °C and a reaction time of 1 - 10 h; more preferably, the conditions of the esterification reaction may include: a reaction temperature of 25 - 120 °C and a reaction time of 2 - 8 h.

[0044] In a preferred embodiment of the present invention, the amidation reaction and the esterification reaction are carried out in the presence of a protective gas; preferably, the protective gas may be at least one of nitrogen or noble gases; more preferably, it may be nitrogen.

[0045] In a preferred embodiment of the present invention, the method further includes recovering the alcohol in the esterification reaction product, wherein the structure of the alcohol may be HR 6 。

[0046] In a preferred embodiment of the present invention, the method further includes recovering the organic acid in the cracking reaction product, wherein the structure of the organic acid may be

[0047] In the present invention, there are no particular requirements for the conditions of the cracking reaction. Preferably, the cracking reaction conditions may include: a reaction temperature of 80 - 150 °C and a reaction time of 2 - 8 h; more preferably, the cracking reaction conditions may include: a reaction temperature of 90 - 120 °C and a reaction time of 3 - 5 h; preferably, the cracking is carried out in the presence of a cracking catalyst, wherein the cracking catalyst is at least one of ZSM - 35 molecular sieve or NAY molecular sieve, preferably ZSM - 35 molecular sieve; preferably, relative to 1 mol of the ester group in the ester compound, the amount of the cracking catalyst used is 5 - 100 g, more preferably 10 - 50 g.

[0048] In a preferred embodiment of the present invention, the method further includes: recovering the alcohol in the esterification reaction product and the organic acid in the cracking product, and contacting the recovered organic acid with the alcohol for reaction to obtain the benzene - based derivative for reuse in step (2). By reusing the benzene - based derivative, the amount of raw materials can be significantly reduced. And the contact between the organic acid and the alcohol only needs to be heated under acidic conditions.

[0049] In a preferred embodiment of the present invention, the raw materials are dissolved in a solvent, wherein the solvent is a commonly used solvent in the art. Preferably, the solvent may be at least one of toluene or dichloroethane.

[0050] In a preferred embodiment of the present invention, organic amines may be present in the raw materials, wherein the organic amines are commonly used organic amines in the art. Preferably, the organic amines may be at least one of pyridine or triethylamine.

[0051] In a preferred embodiment of the present invention, the method further includes quenching the reaction system. There are no special requirements for the quenching conditions, as long as the reaction can be terminated. The reaction system can be cooled first and then a quenching reagent can be added. The quenching reagent selected may be at least one of sodium carbonate or sodium bicarbonate.

[0052] In the present invention, the method may further include the step of purifying the lipid compound from the esterification reaction product. The purification can be carried out in a common manner in the art. For example, the purification may include successively extracting, dehydrating, and rotary evaporating the acylation reaction product. In a preferred embodiment of the present invention, the quenched reaction system is extracted. The extraction can be a commonly used method in the art. Preferably, the extraction liquid is selected from at least one of dichloromethane and dichloroethane. More preferably, the extraction is carried out by multiple extractions.

[0053] In a preferred embodiment of the present invention, the method may further include dehydrating the extracted organic phase. The dehydration can be carried out in a commonly used manner in the art. Preferably, the dehydration method is at least one of adding a dehydrating agent and rotary evaporation; the dehydrating agent is selected from at least one of Na 2 SO 4 and MgSO 4 in at least one of them.

[0054] In a preferred embodiment of the present invention, the method may further include the step of removing impurities. The removal of impurities can be carried out in a commonly used manner in the art. Preferably, the method for removing impurities can be one of extraction or vacuum rectification.

[0055] The present invention also relates to a method for preparing a polymer, which method comprises: preparing an N-alkenylamide according to the method described above; then mixing the obtained N-alkenylamide as monomer D' with monomer A', monomer B', monomer C' and an initiator and carrying out a polymerization reaction under solution polymerization reaction conditions. The polymer prepared according to this method has both the ability to thicken the aqueous phase and the performance of emulsifying heavy oil with low dynamic viscosity, can reduce the viscosity of heavy oil, and is applicable to the exploitation of waterflood reservoirs. Among them, monomer A', monomer B', monomer C', the initiator, the polymerization reaction, etc. are detailed in CN202311522670.5, CN202311522771.2 or CN202311519415.5, which are hereby incorporated herein by reference in their entirety.

[0056] The present invention will be described in detail below through examples. For those not specifying specific conditions in the following examples and comparative examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial channels.

[0057] The ZSM-35 molecular sieve was purchased from Zhuoyue Environmental Protection New Materials Co., Ltd., and the product number is NA-H35-P02M.

[0058] Yield = actual output of the target product / theoretical production amount of the target product × 100%. The yield of N-alkenylamide is calculated based on the theoretical production amount calculated from the alcohol amine / acyl compound.

[0059] The detection method for the purity of N-vinylamide is to detect it by the internal standard method of nuclear magnetic resonance hydrogen spectrum.

[0060] Example 1

[0061] (1) Take ethanolamine (100 mmol), after purging with nitrogen and removing oxygen, cool it to 0 °C, add dichloroethane (100 mL) and triethylamine (140 mmol), and then slowly dropwise add formyl chloride (120 mmol), and react at 0 °C for 4 h; after the reaction is completed, carry out reduced pressure distillation to obtain 2-hydroxyethylformamide.

[0062] (2) Take the 2-hydroxyethylformamide (98 mmol) prepared in step (1), after purging with nitrogen and removing oxygen, add triethylamine (118 mmol). Take terephthaloyl chloride (54 mmol) and dissolve it in dichloroethane (200 mL), and dropwise add this dichloromethane solution to the reaction at room temperature of 25 °C, and react for 2 h; after the reaction is completed, quench the reaction system with a 10% saturated sodium bicarbonate solution (200 mL), and extract the reaction product with dichloroethane three times, with the amount of dichloroethane used for each extraction being 100 mL, MgSO 4 Dry the organic phase and rotary evaporate to obtain a diester compound.

[0063] (3) Mix the diester compound (45 mmol) obtained in step (2) with 0.9 g of ZSM-35 molecular sieve, and pyrolyze at 120 °C for 3 h to obtain crude N-vinylformamide. N-vinylformamide is obtained by vacuum rectification. The yield of the obtained product N-vinylformamide is 83.5%, and the purity is 96.1%.

[0064] Analysis by nuclear magnetic resonance hydrogen spectrum shows the following results: 1 H NMR (500 MHz, DMSO) δ 10.13–9.81 (m, 2H, NH), 8.29 (d, J = 10.9 Hz, 1H, H-C(O)), 8.02 (s, 1H, H-C(O)), 6.93–6.78 (m, 1H, CH=CH 2 ), 6.74–6.59 (m, 1H, CH=CH 2 ), 4.71 (d, J = 16.0 Hz, 1H, CH=CH 2 ), 4.52 (d, J = 15.5 Hz, 1H, CH=CH 2 ), 4.40–4.36 (m, 1H, CH=CH 2 ), 4.19 (t, J = 9.6 Hz, 1H, CH=CH 2 ). This proves that N-vinylformamide is obtained in Example 1.

[0065] Example 2

[0066] (1) Take ethanolamine (100 mmol), cool to 0 °C after purging with nitrogen to remove oxygen, add dichloroethane (100 mL) and triethylamine (140 mmol), and then slowly dropwise add formyl chloride (200 mmol), and react at 25 °C for 2 h; after the reaction is completed, vacuum distillation is carried out to obtain 2-hydroxyethylformamide.

[0067] (2) Take the 2-hydroxyethylformamide (95 mmol) prepared in step (1), add terephthalic acid (70 mmol) and p-toluenesulfonic acid (5 mmol); after purging with nitrogen to remove oxygen, add toluene (200 mL), reflux and separate water at 120 °C, and react for 7 h; after the reaction is completed, naturally cool to room temperature, quench the reaction system with a 10% saturated sodium bicarbonate solution (200 mL), and extract the reaction product with dichloroethane three times, with the amount of dichloroethane used for each extraction being 100 mL, and dry the organic phase with MgSO 4 and rotary evaporate to obtain a mixture of monoester and diester.

[0068] (3) Mix the monoester and diester mixture (46 mmol) obtained in step (2) with 2.3 g of ZSM-35 molecular sieve, and pyrolyze at 110 °C for 4 h to obtain crude N-vinylformamide. After vacuum distillation, N-vinylformamide is obtained. The yield of N-vinylformamide in the obtained product is 82.6%, and the purity is 97.1%.

[0069] Example 3

[0070] (1) Take ethanolamine (100 mmol), add ethyl acetate (300 mmol), purge with nitrogen to remove oxygen, and react at 90 °C for 8 h; after the reaction is completed, perform vacuum distillation to obtain 2-hydroxyethylacetamide.

[0071] (2) Take 2-hydroxyethylacetamide (100 mmol) prepared in step (1), add methyl p-trifluoromethylbenzoate (120 mmol) and p-toluenesulfonic acid (20 mmol), purge with nitrogen to remove oxygen, then heat to 90 °C and react for 8 h, while refluxing to recover the methanol generated in the reaction; after the reaction is completed, quench the reaction system with a 10% saturated sodium bicarbonate solution (200 mL), and extract the reaction product three times with dichloroethane, with the amount of dichloroethane used for each extraction being 100 mL. 4 Dry the organic phase, and after rotary evaporation, an ester compound is obtained.

[0072] (3) Mix the ester compound (94 mmol) obtained in step (2) with 4.7 g of ZSM-35 molecular sieve, and pyrolyze at 90 °C for 5 h to obtain crude N-vinylacetamide. The crude product is subjected to vacuum distillation to obtain N-vinylacetamide. The yield of the obtained product N-vinylacetamide is 89.5%, and the purity is 95.9%. Add the methanol recovered in step (2) to the mixture that has not been distilled off after vacuum distillation, then filter the ZSM-35 molecular sieve to obtain a mixture of p-trifluoromethylbenzoic acid and methanol, and carry out an esterification reaction by heating under the catalysis of concentrated sulfuric acid; after the reaction is completed, add a 10% sodium bicarbonate solution to quench the reaction, distill off the methanol, and then separate the layers to obtain methyl p-trifluoromethylbenzoate.

[0073] Example 4

[0074] (1) Take ethanolamine (100 mmol), add ethyl acetate (500 mmol), purge with nitrogen to remove oxygen, and react at 120 °C for 10 h; after the reaction is completed, perform vacuum distillation to obtain 2-hydroxyethylacetamide.

[0075] (2) Take 2-hydroxyethylacetamide (81 mmol) obtained in step (1), add terephthalic acid (41 mmol) and p-toluenesulfonic acid (4 mmol); after purging with nitrogen to remove oxygen, add toluene (200 mL), reflux and separate water at 150 °C for 10 h; after the reaction is completed, cool naturally to room temperature, quench the reaction system with 10% saturated sodium bicarbonate solution (200 mL), and extract the reaction product three times with dichloroethane, with 100 mL of dichloroethane used each time, and MgSO 4 Dry the organic phase and obtain the diester compound after rotary evaporation.

[0076] (3) Mix the diester compound (30 mmol) obtained in step (2) with 6 g of ZSM-35 molecular sieve, pyrolyze at 80 °C for 8 h to obtain crude N-vinylacetamide. After vacuum distillation, N-vinylacetamide is obtained. The yield of the obtained product N-vinylacetamide is 65.3%, and the purity is 72.5%.

[0077] Example 5

[0078] (1) Take N-ethanolamine (100 mmol), after purging with nitrogen to remove oxygen, cool to 0 °C, add dichloroethane (100 mL) and triethylamine (120 mmol), and then slowly dropwise add formyl chloride (80 mmol), react at -10 °C for 5 h; after the reaction is completed, perform vacuum distillation to obtain 2-hydroxyethyl-N-methylformamide.

[0079] (2) Take 2-hydroxyethyl-N-methylformamide (74 mmol) prepared in step (1), after purging with nitrogen to remove oxygen, add triethylamine (90 mmol), dissolve p-trifluoromethylbenzoyl chloride (180 mmol) in dichloroethane (200 mL), and dropwise add this dichloromethane solution to the reaction at 0 °C, react for 1 h; after the reaction is completed, cool naturally to room temperature, quench the reaction system with 10% saturated sodium carbonate solution (200 mL), and extract the reaction product three times with dichloroethane, with 100 mL of dichloroethane used each time, and MgSO 4 Dry the organic phase and obtain the ester compound after rotary evaporation.

[0080] (3) Mix the ester compound (50 mmol) obtained in step (2) with 0.25 g of ZSM-35 molecular sieve, pyrolyze at 150 °C for 2 h to obtain crude N-methyl-N-vinylformamide. After vacuum distillation, N-methyl-N-vinylformamide is obtained. The yield of the obtained product N-methyl-N-vinylformamide is 54.9%, and the purity is 80.3%.

[0081] Example 6

[0082] (1) Take ethanolamine (100 mmol). After purging with nitrogen to remove oxygen, cool it down to 0 °C, add dichloroethane (100 mL) and triethylamine (140 mmol), and then slowly dropwise add formyl chloride (60 mmol). React at -10 °C for 11 h. After the reaction is completed, perform vacuum distillation to obtain 2-hydroxyethylformamide.

[0083] (2) Take 2-hydroxyethylformamide (35 mmol) prepared in step (1). After purging with nitrogen to remove oxygen, add triethylamine (500 mmol). Dissolve p-trifluoromethylbenzoyl chloride (105 mmol) in dichloroethane (200 mL). Dropwise add this dichloromethane solution to the reaction at -5 °C and react for 12 h. After the reaction is completed, quench the reaction system with a 10% saturated sodium bicarbonate solution (100 mL). Extract the reaction product with dichloroethane three times, with the amount of dichloroethane used for each extraction being 100 mL, Mg 2 SO 4 Dry the organic phase and rotary evaporate to obtain an ester compound.

[0084] (3) Mix the ester compound (10 mmol) obtained in step (2) with 1.5 g of ZSM-35 molecular sieve and crack at 70 °C for 2 h to obtain crude N-vinylformamide. Perform vacuum rectification to obtain N-vinylformamide. The yield of the obtained product N-vinylformamide is 11.5%, and the purity is 40.5%.

[0085] Example 7

[0086] (1) Take ethanolamine (100 mmol). After purging with nitrogen to remove oxygen, cool it down to 0 °C, add dichloroethane (100 mL) and triethylamine (140 mmol), and then slowly dropwise add formyl chloride (500 mmol). React at 140 °C for 0.5 h. After the reaction is completed, perform vacuum distillation to obtain 2-hydroxyethylformamide.

[0087] (2) Take 2-hydroxyethylformamide (27 mmol) prepared in step (1), add terephthalic acid (12 mmol) and p-toluenesulfonic acid (1 mmol). After purging with nitrogen to remove oxygen, add toluene (200 mL) and reflux and separate water at 170 °C for 0.5 h. After the reaction is completed, naturally cool to room temperature, quench the reaction system with a 10% saturated sodium bicarbonate solution (50 mL). Extract the reaction product with dichloroethane three times, with the amount of dichloroethane used for each extraction being 100 mL, MgSO 4 Dry the organic phase and rotary evaporate to obtain a diester compound.

[0088] (3) Mix the diester compound (3 mmol) obtained in step (2) with 0.003 g of ZSM-35 molecular sieve and pyrolyze at 160 °C for 10 h to obtain crude N-vinylformamide. N-vinylformamide is obtained by vacuum distillation. The yield of the obtained product N-vinylformamide is 5.4%, and the purity is 21.8%.

[0089] Comparative Example 1

[0090] (1) Take ethanolamine (100 mmol), cool to 0 °C after purging with nitrogen and removing oxygen, add dichloroethane (100 mL) and triethylamine (140 mmol), and then slowly dropwise add formyl chloride (1.2 mol) and react at 0 °C for 4 h; after the reaction is completed, vacuum distillation is carried out to obtain 2-hydroxyethylformamide.

[0091] (2) Mix the 2-hydroxyethylformamide (20 mmol) obtained in step (1) with 0.9 g of ZSM-35 molecular sieve and pyrolyze at 120 °C for 3 h to obtain a mixture. N-vinylformamide is obtained by vacuum distillation. N-vinylformamide was not detected in the obtained mixture.

[0092] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A method for preparing an N-alkenyl amide compound, characterized in that: The preparation method comprises: (1) optionally, mixing an alcohol amine represented by formula (I) with at least one acyl compound represented by formula (II) to carry out an amidation reaction to obtain an N-(2-hydroxyalkyl)amide; Among them, R 1 R is selected from a hydrogen atom or a C1-C5 alkyl group; 2 and R 3 R is selected from a hydrogen atom or a C1-C5 alkyl group; 4 is selected from chlorine, bromine or C1-C5 alkoxy; (2) contacting N-(2-hydroxyalkyl)amide with a benzene derivative represented by formula (III) to carry out an esterification reaction; Among them, R 5 An electron withdrawing group selected from C1-C5; R 6 Selected from chlorine, bromine, hydroxyl or C1-C5 alkoxy; (3) subjecting the product of step (2) to a cleavage reaction.

2. The preparation method according to claim 1, wherein The molar ratio of the alcoholamine to the acyl compound is 1:0.8-10; preferably 1:1.2-3.

3. The preparation method according to claim 1 or 2, wherein The molar ratio of the N-(2-hydroxyalkyl)amide to the benzene derivative is 1:0.5-2.5; preferably 1:0.55-1.

4.

4. The preparation method according to any one of claims 1 to 3, wherein The alcohol amine is selected from 2-hydroxyethylamine, 2-amino-1-propanol, 2-amino-1-butanol, 2-amino-1-pentanol, 2-amino-3-methyl-1-butanol, 2-amino-1-hexanol, 2-amino-4-methyl-1-pentanol, 2-amino-3-methyl-1-pentanol, 2-amino-1-heptanol, 2-amino-5-methyl-1-hexanol, N-methyl-2-hydroxyethylamine, N-ethyl-2-hydroxyethylamine, N-propyl- At least one of 2-hydroxyethylamine, N-isopropyl-2-hydroxyethylamine, N-butyl-2-hydroxyethylamine, N-isobutyl-2-hydroxyethylamine, N-pentyl-2-hydroxyethylamine, N-((3-methylbutyl)amino)ethanol, N-((2-methylbutyl)amino)ethanol, 2-methylamino-1-propanol, 2-methylamino-1-butanol, 2-methylamino-1-pentanol, 2-methylamino-1-hexanol or 2-methylamino-1-heptanol; Preferably, the alcoholamine is selected from at least one of 2-hydroxyethylamine, N-methyl-2-hydroxyethylamine, N-ethyl-2-hydroxyethylamine, N-propyl-2-hydroxyethylamine, 2-amino-1-propanol, 2-amino-1-butanol, 2-amino-1-pentanol or 2-methylamino-1-propanol.

5. The preparation method according to any one of claims 1 to 4, wherein: The acyl compound is selected from at least one of formyl chloride, acetyl chloride, propionyl chloride, butyryl chloride, valeryl chloride, formyl bromide, acetyl bromide, propionyl bromide, butyryl bromide, valeryl bromide, methyl formate, ethyl formate, propyl formate, butyl formate, pentyl formate, ethyl acetate, ethyl acetate, propyl acetate, butyl acetate, pentyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, pentyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, pentyl butyrate, methyl valerate, ethyl valerate, propyl valerate, butyl valerate, pentyl valerate, methyl hexanoate, ethyl hexanoate, propyl hexanoate, butyl hexanoate or pentyl hexanoate; Preferably, the acyl compound is selected from at least one of formyl chloride, acetyl chloride, propionyl chloride, methyl formate, ethyl formate, ethyl acetate or ethyl propionate.

6. The preparation method according to any one of claims 1 to 5, wherein: The benzene derivatives are selected from phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, p-trifluoromethylbenzoyl chloride, p-cyanobenzoyl chloride, m-trifluoromethylbenzoyl chloride, m-cyanobenzoyl chloride, o-trifluoromethylbenzoyl chloride, o-cyanobenzoyl chloride, phthaloyl bromide, isophthaloyl bromide, terephthaloyl bromide, p-trifluoromethylbenzoyl bromide, p-cyanobenzoyl bromide, m-trifluoromethylbenzoyl bromide, m-cyanobenzoyl bromide, o-trifluoromethylbenzoyl bromide, o-cyanobenzoyl bromide, phthalic acid, isophthalic acid Diphthalic acid, terephthalic acid, o-trifluoromethylbenzoic acid, o-cyanobenzoic acid, m-trifluoromethylbenzoic acid, m-cyanobenzoic acid, p-trifluoromethylbenzoic acid, p-cyanobenzoic acid, methyl phthalate, methyl isophthalate, methyl terephthalate, methyl p-trifluoromethylbenzoate, methyl p-cyanobenzoate, methyl m-trifluoromethylbenzoate, m-cyanobenzoate, methyl o-trifluoromethylbenzoate, methyl o-cyanobenzoate, ethyl phthalate, ethyl isophthalate, ethyl terephthalate, p-trifluoromethylbenzoate Ethyl fluoromethylbenzoate, ethyl p-cyanobenzoate, ethyl m-trifluoromethylbenzoate, ethyl m-cyanobenzoate, ethyl o-trifluoromethylbenzoate, ethyl o-cyanobenzoate, propyl isophthalate, propyl terephthalate, propyl p-trifluoromethylbenzoate, propyl p-cyanobenzoate, propyl m-trifluoromethylbenzoate, propyl m-cyanobenzoate, propyl o-trifluoromethylbenzoate, propyl o-cyanobenzoate, butyl isophthalate, butyl terephthalate, butyl p-trifluoromethylbenzoate, butyl p-cyanobenzoate at least one of ester, butyl m-trifluoromethyl benzoate, butyl m-cyanobenzoate, amyl isophthalate, amyl terephthalate, amyl p-trifluoromethyl benzoate, amyl p-cyanobenzoate, amyl m-trifluoromethyl benzoate, amyl m-cyanobenzoate, tris-benzoyl chloride, tris-benzoyl bromide, tris-benzoic acid, methyl tris-benzoate, tris-benzoyl chloride, tris-benzoyl bromide, tris-benzoic acid, methyl tris-benzoate, mes-tris-benzoyl chloride, mes-tris-benzoyl bromide, mes-tris-benzoic acid or mes-tris-benzoic acid methyl ester; Preferably, the benzene derivative is selected from at least one of isophthaloyl chloride, terephthaloyl chloride, p-trifluoromethylbenzoyl chloride, isophthalic acid, terephthalic acid, p-trifluoromethylbenzoic acid, p-cyanobenzoic acid, methyl isophthalate, methyl terephthalate, methyl p-trifluoromethylbenzoate, methyl p-cyanobenzoate, ethyl isophthalate, ethyl terephthalate, ethyl p-trifluoromethylbenzoate, ethyl p-cyanobenzoate, mesitylene tribenzoyl chloride or mesitylene tribenzoic acid.

7. The preparation method according to any one of claims 1 to 6, wherein: The conditions of the amidation reaction include: reaction temperature of 0-120°C, reaction time of 1-10h; Preferably, the conditions for the amidation reaction include: reaction temperature of 0-90° C., and reaction time of 2-8 h.

8. The preparation method according to any one of claims 1 to 7, wherein: The conditions of the esterification reaction include: reaction temperature of 0-150°C, reaction time of 1-10h; Preferably, the conditions of the esterification reaction include: reaction temperature of 25-120° C., and reaction time of 2-8 h.

9. The preparation method according to any one of claims 1 to 8, wherein: The amidation reaction and the esterification reaction are carried out in the presence of a protective gas; preferably, the protective gas is at least one of nitrogen or a rare gas; more preferably, nitrogen; And / or, the method further comprises recovering alcohol in the esterification reaction product.

10. The preparation method according to any one of claims 1 to 9, wherein: The cracking reaction conditions include: reaction temperature of 80-150°C and reaction time of 2-8h; Preferably, the cleavage reaction conditions include: reaction temperature of 90-120°C, reaction time of 3-5h; Preferably, the cracking is carried out in the presence of a cracking catalyst, wherein the cracking catalyst is at least one of a ZSM-35 molecular sieve or a NAY molecular sieve, preferably a ZSM-35 molecular sieve; Preferably, the amount of the cleavage catalyst used is 5-100 g, more preferably 10-50 g, relative to 1 mol of ester groups in the ester compound.

11. The preparation method according to any one of claims 1 to 10, wherein: The method further comprises: recovering the alcohol in the esterification reaction product and the organic acid in the cracking product, and contacting the recovered organic acid with the alcohol to react to obtain the benzene derivative for recycling in step (2).

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