CN1284767C

CN1284767C - Synthesis process of methyl ethyl ketone azine

Info

Publication number: CN1284767C
Application number: CN 200510050388
Authority: CN
Inventors: 裴文; 孙孟展; 赵尚原; 马波; 张才
Original assignee: Zhejiang University of Technology ZJUT
Current assignee: Zhejiang University of Technology ZJUT
Priority date: 2005-05-20
Filing date: 2005-05-20
Publication date: 2006-11-15
Anticipated expiration: 2025-05-20
Also published as: CN1706817A

Abstract

The present invention relates to a synthesis method of methyl ethyl ketone azine. The present invention comprises steps that a synthesis reaction is carried out through ammonia, hydrogen peroxide and methyl ethyl ketone at the temperature of 20 to 100 DEG C in a working solution containing a catalyst and ionic liquid; a product is obtained after treatment. The ionic liquid used by the synthesis method of the present invention is not volatile, inflammable and explosive, has favorable safety and can be favorably dissolved in organic matter and inorganic matter, the reaction is carried out under the condition of homogeneous phase so that the present invention has the advantages of convenient operation and processing and high product yield, and ammonia water distilled out of reaction liquid, methyl ethyl ketone and acetonitrile can be recovered and used while the reaction yield is not influenced.

Description

Synthesis method of methyl ethyl ketone azine

(I) technical field

The invention relates to a synthesis method of methyl ethyl ketone azine.

(II) background of the invention

Methyl ethyl ketone azine (Methyl ethyl ketone azine) is an important intermediate product for preparing hydrazine hydrate, and high-quality hydrazine hydrate can be obtained in high yield through hydrolysis. At present, the method for producing methyl ethyl ketazine by using hydrogen peroxide is considered to be the most economical and practical advanced technology and is also a green chemical synthesis technology. The technology has the advantages of simple operation, short reaction time, easily obtained raw materials, low cost and high product yield, and has extremely important significance in preparing hydrazine hydrate by utilizing the methyl ethyl ketazine method.

Hydrazine hydrate is widely used chemicals with various purposes, is mainly used for synthesis of pesticides and medicines, water treatment agents and polymer foaming agents, has important application inhigh-tech fields such as rocket fuels, fuel cells and the like, and has huge market demand. In China, the production cost is high, the production scale is difficult to expand, and the application of hydrazine is limited to a certain extent. Therefore, the development of economic and practical production technology by improving the production process is always the focus of research.

At present, the production process routes of hydrazine hydrate mainly comprise four routes.

The first is the Raschig process, an ancient process for the industrial production of hydrazine, which uses ammonia as a raw material and produces hydrazine by oxidation with sodium hypochlorite. The reaction for synthesizing hydrazine by the Raschig method is carried out in two steps, and the reaction formula is as follows:

the reaction of chloramine and ammonia to hydrazine under alkaline conditions is slow and needs to be carried out at 130-200 ℃ under pressure. In actual production, there is also a side reaction, i.e. the hydrazine produced is further oxidized by chloramine to produce ammonium chloride and nitrogen, the reaction formula is as follows:

in order to reduce side reaction, ammonia is usually excessive, so that the concentration of hydrazine in a product in a reaction solution is low, a large amount of ammonia water needs to be separated and recycled, and more steam is consumed for distillation and concentration of the hydrazine in the product. The method is basically eliminated due to low hydrazine yield and high production cost.

The second is urea oxidation method, which is to react urea water solution with sodium hypochlorite and caustic soda under the action of catalyst to produce hydrazine hydrate. It is an improvement of the Raschig process and is characterized by the use of urea as a nitrogen source instead of ammonia, thereby avoiding the circulation of large amounts of ammonia. The reaction formula is as follows:

in this process, hydrazine hydrate is obtained by oxidation of urea with sodium hypochlorite. Because the reactant sodium hypochlorite is a strong oxidant and the product is a strong reducing agent, the following side reaction exists in the reaction process, wherein hydrazine hydrate is oxidized by the sodium hypochlorite:

this side reaction is very severe. When the batching or operation is improper, the spraying accident can happen, so the yield of the urea oxidation method is low. The process is eliminated abroad, but the process is still adopted domestically because the process is very simple and the investment is saved.

The third method is the oxidation of ketazine by chlorine or sodium hypochlorite, which is first proposed by Bayer in Germany, where ammonia is oxidized by chlorine or sodium hypochlorite in the presence of aliphatic ketones to form ketazine, hydrazone or isohydrazone, and when the ketone is in excess, the hydrazone and isohydrazone can be converted to ketazine, and these intermediates are hydrolyzed under high pressure to form hydrazine hydrate. The reaction formula is as follows:

the method has a qualitative breakthrough in hydrazine preparation technology, but because the raw material still adopts a chlorine product, the defects that the hydrazine product is easy to oxidize and the reaction medium has strong corrosivity always exist in the technology; there are disadvantages in that the separation of the product is difficult and a large amount of by-products are produced economically.

The fourth method is oxidation of ketazine with hydrogen peroxide, the synthesis process is that under the existence of ketone and nitrile catalyst, ammonia and hydrogen peroxide are used as raw materials to react in liquid phase to obtain ketazine, and the ketazine is hydrolyzed to obtain ketone and hydrazine hydrate. The reaction formula is as follows:

the reaction condition is mild, hydrogen peroxide is used for replacing chlorine products as an oxidant, the yield is high, the method is the most advanced technology for preparing hydrazine hydrate at present, is a breakthrough of hydrazine production technology, and is also a green synthesis technology.

The hydrogen peroxide method described in Chinese patent CN1242339 comprises the following steps: (1) adding ammonia, hydrogen peroxide and butanone (methyl ethyl ketone) into a working solution containing a catalyst to react and synthesize ketazine; (2) separating the reaction mixture into a ketazine layer and a working liquid layer; (3) recovering unreacted methyl ethyl ketone from the separated ketone nitrogen connecting layer; (4) removing impurities (mainly sec-butyl alcohol) generated by side reaction from unreacted methyl ethyl ketone, and reusing the recovered methyl ethyl ketone for preparing ketazine;(6) hydrolysis of ketazine to obtain hydrazine hydrate and recovering methyl ethyl ketone. The hydrogen peroxide process described in the patent is the synthesis of ketazine using hydrogen peroxide, ammonia and a ketone in an aqueous solution containing acetamide and sodium phosphate. However, in this method, impurities generated by the side reaction are recovered together with the unreacted ketone and reused, and the yield of synthesized ketazine gradually decreases due to accumulation of impurities, which makes separation of the product difficult.

Disclosure of the invention

The invention aims to provide a synthesis method for synthesizing methyl ethyl ketazine, which has mild reaction conditions and high yield.

The methyl ethyl ketone azine is shown as a formula (I), and the synthesis method comprises the following steps: and (3) performing synthetic reaction on ammonia, hydrogen peroxide and methyl ethyl ketone in a working solution containing a catalyst and an ionic liquid at the temperature of 20-100 ℃, and performing post-treatment to obtain a product.

The catalyst is dissolved or dispersed (suspended) in the ionic liquid in the working solution. The working solution may also contain water, alcohol, etc., and the alcohol can be methanol, ethanol, ethylene glycol, propylene glycol, 1, 3-propylene glycol or 1, 5-pentanediol. The post-treatment of the product can be to extract the ionic liquid by using an organic solvent to obtain the product, and the ionic liquid can be continuously recycled.

The ionic liquid is alkyl imidazole tetrafluoroborate, alkyl imidazole hexafluorophosphate, alkyl imidazole acetate or aromatic imidazole tetrafluoroborate, etc. The alkyl in the alkyl imidazole tetrafluoroborate and the alkyl imidazole acetate is preferably aliphatic C₁～C₁₀An alkyl substituent, more preferably 1-butyl-3-methylimidazolium tetrafluoroborate or 1-butyl-3-methylimidazolium acetate; the arene imidazole tetrafluoroborate is preferably arene C₇～C₁₀The substituent (b) is more preferably 1-benzyl-3-methylimidazolium tetrafluoroborate.

The catalyst may be one or a mixture of any of inorganic or organic amides or imines, amine salts, arsenic compounds or nitriles, the amide or imine may be cyanoacetamide, formamide, chloroacetamide, bromoacetamide, dichloroacetamide, trichloroacetamide, trifluoroacetamide, α -chloropropionamide, β -chloropropionamide, β, β 2-dichloropropionamide, β, β 1-dichloropropionamide, β 5-bromopropionamide, β 3-bromopropionamide, β, β -dibromopropionamide, α -chloroisobutyramide, perfluorobutyramide, ethyleneglycolamide, lactic acid amide, β -hydroxypropionamide, glycerylamine, α -hydroxy- β -chloropropionamide, phenylacetamide, chlorophenylacetamide, bromophenylacetamide, fluorophenylacetamide, nitrobenzoacetamide, 2, 4-dinitrophenylacetamide, diphenylacetamide, aniline, o-toluidine, m-toluidine, chloroaniline, bromoaniline, fluoroaniline, iodoaniline, pentachloroaniline, pentafluorophenylamine, nitropropionamide, nitro-o-methyl-o-salicylamide, salicylic acid-methylacetamide, salicylic acid-o-methylacetamide, citric acid-propionic acid, citric acid-o-methylacetamide, citric acid-methylacetamide, succinic acid-hexachlorobenzoic acid, succinic acid-methylacetamide, citraconic acid-methylacetamide, succinic acid-methylacetamide, citraconic acid, succinic acid, citraconic acid-hexachlorobenzoic acid, citraconic acid.

The ammonia can be liquid ammonia or gaseous ammonia, and is preferably commercial ammonia water containing 25-28% of ammonia.

The hydrogen peroxidecan be used in a common industrial form, such as containing 30-90% (mass content) of H₂O₂The aqueous solution is used. It is advantageous to add conventional stabilizers for solutions of one or more hydrogen peroxides, such as phosphoric acid, pyrophosphoric acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid or amine or alkali metal salts of these acids and arsenates, phosphites, polyphosphates, hydrogenphosphates, stannates, antimonates, amine sulfonates or (C) thereof₁～C₅) Saturated alkyl esters, preferably phosphates, more preferably sodium hexametaphosphate. The amount of the catalyst is 10 to 1000ppm, preferably 50 to 250ppm, based on the reaction solution.

The feeding molar ratio of the hydrogen peroxide to the methyl ethyl ketone to the ammonia to the ionic liquid to the catalyst is preferably 1: 0.2-5: 1-10: 0.5-3: 1-5, and more preferably 1: 1.5-4: 1-2: 1.2-4.6. When the catalyst is a mixture of acetonitrile and cyanoacetamide, the feeding molar ratio of hydrogen peroxide to acetonitrile is preferably 1: 1-4, and more preferably 1.5: 3.5; the feeding molar ratio of the hydrogen peroxide to the cyanoacetamide is preferably 1: 0.2-0.6, and more preferably 1: 0.3-0.4.

The synthesis reaction temperature is preferably 30-70 ℃; the reaction time is preferably 1 to 8 hours, and more preferably 2 to 8 hours.

The reaction can be carried out with or without stirring.

When a mixture of acetonitrile and cyanoacetamide is used as the catalyst, the recommended feeding sequence of the invention is as follows: cyanoacetamide, acetonitrile, water or ionic liquid, sodium hexametaphosphate, ammonia water and butanone can be added in any order, and finally hydrogen peroxide is dripped.

The acetonitrile, ammonia water and butanone used in the reaction may be commercial productsin the initial reaction, and thereafter, the acetonitrile, ammonia water and butanone obtained by recovery may be partially or completely used in the reaction.

The 2-butanol which is unfavorable to the reaction is generated in the reaction and is distilled off together with water, and the obtained acetonitrile, ammonia water and butanone are recovered and reused for the reaction without influencing the yield.

The synthesis reaction is also recommended to be carried out under ultrasonic irradiation. The ultrasonic radiation greatly shortens the reaction time, improves the yield and reduces the energy consumption. The ultrasonic instrument can be various ultrasonic cleaners for experiments

The green chemical method for synthesizing methyl ethyl ketone azine has the following beneficial effects:

(1) the ionic liquid is used, is not easy to volatilize, is not flammable and explosive, has good safety, has good solubility on organic matters and inorganic matters, is convenient to operate and treat because the reaction is carried out under the homogeneous condition, and has high product yield.

(2) The ionic liquid is easy to recycle.

(3) The ammonia water, methyl ethyl ketone and acetonitrile distilled from the reaction solution can be recycled, and the reaction yield is not influenced.

(4) If the reaction is promoted by ultrasonic wave, the reaction time is shortened, the yield is improved, the energy consumption is saved, and the method is beneficial to industrial production.

(IV) detailed description of the preferred embodiments

The invention is further illustrated by the following specific examples, without limiting the scope of the invention thereto.

EXAMPLE 1 Synthesis of methyl Ethyl Ketone Azide in 1-butyl-3-methylimidazolium tetrafluoroborate Ionic liquid

Cyanoacetamide (6g, 71.4mmol), 1-butyl-3-methylimidazolium tetrafluoroborate (20ml), sodium hexametaphosphate (0.6g, 1.0mmol), acetonitrile (20ml, 586mmol), 28% (mass content) ammonia (50ml, 588mmol), butanone (54ml, 588mmol), 30% (mass content) hydrogen peroxide (20ml, 196mmol) were added in this order to a 250ml three-necked round-bottomed flask equipped with a thermometer and a condenser, the reaction mixture was stirred at 40 ℃ for 8 hours, the reaction mixture was distilled, ammonia, butanone, acetonitrile, 2-butanol, and water were distilled off, and the remaining solution was extracted with dichloromethane to recover an ionic liquid, whereby 16.05g of a product was obtained, and the yield was 58.6% (based on hydrogen peroxide).

EXAMPLE 2 Synthesis of methyl Ethyl Ketone Azide in 1-benzyl-3-methylimidazolium tetrafluoroborate Ionic liquid

Cyanoacetamide (3g, 35.7mmol), 1-benzyl-3-methylimidazolium tetrafluoroborate (10ml), sodium hexametaphosphate (0.3g, 0.5mmol), acetonitrile (10ml, 293mmol), 28 mass% ammonia (25ml, 294mmol), butanone (27ml, 294mmol) were added in this order to a 100ml three-necked round-bottomed flask equipped with a thermometer and a condenser, 30 mass% hydrogen peroxide (10ml, 98mmol) was added dropwise thereto, the mixture was stirred at 50 ℃ for 8 hours, the reaction mixture was distilled, ammonia, butanone, acetonitrile, 2-butanol and water were distilled off, and the remaining solution was extracted with dichloromethane to recover an ionic liquid, whereby 7.74g of a product was obtained, and the yield was 56.5% (based on hydrogen peroxide).

EXAMPLE 3 Synthesis of methyl Ethyl Ketone Azide in 1-butyl-3-methylimidazolium acetate Ionic liquid

Cyanoacetamide (3g, 35.7mmol), 1-butyl-3-methylimidazolyl acetate (10ml), sodium hexametaphosphate (0.3g, 0.5mmol), acetonitrile (10ml, 293mmol), 28 mass% ammonia (25ml, 294mmol), butanone (27ml, 294mmol) were sequentially added to a 100ml three-necked round bottom flask equipped with a thermometer and a condenser, hydrogen peroxide (10ml, 98mmol) was added dropwise, the reaction mixture was stirred at 45 ℃ for 6 hours, the reaction mixture was distilled off, ammonia, butanone, acetonitrile, 2-butanol, and water were distilled off, and the remaining solution was extracted with toluene to recover an ionic liquid, whereby 12.03g of a product was obtained, and the yield was 87.8% (based on hydrogen peroxide).

The ionic liquid in the reaction system can be continuously recycled.

Example 4 Synthesis of methyl Ethyl Ketone Azide in 1-butyl-3-methylimidazolium tetrafluoroborate Ionic liquid promoted by ultrasound

Cyanoacetamide (3g, 35.7mmol), 1-butyl-3-methylimidazolium tetrafluoroborate (10ml), acetonitrile (10ml, 293mmol), sodium hexametaphosphate (0.3g, 0.5mmol), 28% (mass content) ammonia (25ml, 294mmol) and butanone (27ml, 294mmol) are sequentially added to a 100ml single-neck round-bottom flask, 30% (mass content) hydrogen peroxide (10ml, 98mmol) is added dropwise, reaction is carried out for 2 hours under the promotion of ultrasonic waves, the reaction solution is distilled, ammonia, butanone, acetonitrile, 2-butanol and water are removed by evaporation, and the residual solution is extracted by dichloromethane to recover ionic liquid, so that 10.0g of a product is obtained, and the yield is 73.0% (calculated by hydrogen peroxide).

Example 5 Synthesis of methyl Ethyl Ketone Azide in 1-benzyl-3-methylimidazolium tetrafluoroborate Ionic liquid promoted by ultrasound

Cyanoacetamide (3g, 35.7mmol), 1-benzyl-3-methylimidazolium tetrafluoroborate (10ml), sodium hexametaphosphate (0.3g, 0.5mmol), acetonitrile (10ml, 293mmol), 28% (mass content) ammonia (25ml, 294mmol), butanone (27ml, 294mmol) were added in this order to a 100ml single-neck round-bottom flask, 30% (mass content) hydrogen peroxide (10ml, 98mmol) was added dropwise, reaction was carried out for 2 hours under ultrasonic acceleration, the reaction solution was distilled, ammonia, butanone, acetonitrile, 2-butanol, and water were distilled off, and the remaining solution was extracted with dichloromethane to recover an ionic liquid, yielding 8.84g of a product in 64.5% (based on hydrogen peroxide).

Example 6 Synthesis of methyl Ethyl Ketone Azide in 1-butyl-3-methylimidazolium acetate Ionic liquid promoted with ultrasound

Cyanoacetamide (3g, 35.7mmol), sodium hexametaphosphate (0.3g, 0.5mmol), 1-butyl-3-methylimidazole acetate (10ml), acetonitrile (10ml, 293mmol), 28 mass% ammonia (25ml, 294mmol) and butanone (27ml, 294mmol) were sequentially added to a 100ml round bottom flask, 30 mass% hydrogen peroxide (10ml, 98mmol) was added dropwise, reaction was carried out for 2 hours under ultrasonic acceleration, the reaction solution was distilled, ammonia, butanone, acetonitrile, 2-butanol and water were distilled off, and the remaining solution was extracted with toluene to recover an ionic liquid, whereby 12.20g of a product was obtained, and the yield was 89.1% (based on hydrogen peroxide).

Example 7 Synthesis of methyl Ethyl Ketone Azide in 1-Ethyl-3-methylimidazolium tetrafluoroborate Ionic liquid

Cyanoacetamide (12g, 142.8mmol), 1-ethyl-3-methylimidazolium tetrafluoroborate (20ml), sodium hexametaphosphate (0.6g, 1.0mmol), 28% (mass content) ammonia (50ml, 588mmol), butanone (54ml, 588mmol) are sequentially added into a 250ml three-neck round-bottom flask provided with a thermometer and a condenser, 30% (mass content)hydrogen peroxide (20ml, 196mmol) is dropwise added, the reaction solution is stirred at 40 ℃ for 8 hours, the ammonia, butanone, 2-butanol and water are distilled off, and the residual solution is extracted by dichloromethane to recover ionic liquid, so that 16.85g of a product is obtained, and the yield is 61.5% (calculated on the hydrogen peroxide).

EXAMPLE 8 Synthesis of methyl Ethyl Ketone Azide in 1-butyl-3-methylimidazolium hexafluorophosphate Ionic liquid

Cyanoacetamide (3g, 35.7mmol), 1-butyl-3-methylimidazolium hexafluorophosphate (10ml), sodium hexametaphosphate (0.3g, 0.5mmol), acetonitrile (10ml, 293mmol), 28 mass% aqueous ammonia (25ml, 294mmol), butanone (27ml, 294mmol) were sequentially added to a 100ml three-necked round-bottomed flask equipped with a thermometer and a condenser, 30 mass% hydrogen peroxide (10ml, 98mmol) was added dropwise thereto, the mixture was stirred at 50 ℃ for 8 hours, the reaction mixture was distilled, aqueous ammonia, butanone, acetonitrile, 2-butanol and water were distilled off, and the remaining solution was extracted with dichloromethane to recover an ionic liquid, whereby 6.46g of a product was obtained in a yield of 47.2% (based on hydrogen peroxide).

EXAMPLE 9 Synthesis of methyl Ethyl Ketone Azide in 1-butyl-3-methylimidazolium acetate Ionic liquid

Cyanoacetamide (3g, 35.7mmol), 1-butyl-3-methylimidazolyl acetate (10ml), sodium hexametaphosphate (0.3g, 0.5mmol), acetonitrile (6.80ml, 200mmol), 28% (by mass) aqueous ammonia (25ml, 294mmol), butanone (27ml, 294mmol) were added in this order to a l00ml three-necked round-bottomed flask equipped with a thermometer and a condenser, hydrogen peroxide (10ml, 98mmol) was added dropwise, the mixture was stirred at 60 ℃ for 6 hours, the reaction mixture was distilled, aqueous ammonia, butanone, acetonitrile, 2-butanol, and water were distilled off,and the remaining solution was extracted with toluene to recover an ionic liquid, whereby 12.10g of a product was obtained in 88.3% yield (based on hydrogen peroxide).

EXAMPLE 10 Synthesis of methyl Ethyl Ketone Azide in 1-Ethyl-3-methylimidazolium acetate Ionic liquid

Cyanoacetamide (3g, 35.7mmol), 1-ethyl-3-methylimidazolyl acetate (10ml), sodium hexametaphosphate (0.3g, 0.5mmol), acetonitrile (6.80ml, 200mmol), 28 mass% ammonia (25ml, 294mmol), butanone (27ml, 294mmol) were added sequentially in a 100ml three-necked round-bottomed flask equipped with a thermometer and a condenser, hydrogen peroxide (10ml, 98mmol) was added dropwise, the mixture was stirred at 50 ℃ for 7 hours, the reaction mixture was distilled, ammonia, butanone, acetonitrile, 2-butanol, and water were distilled off, and the remaining solution was extracted with toluene to recover an ionic liquid, whereby 11.45g of a product was obtained in 83.56% yield (based on hydrogen peroxide).

EXAMPLE 11 Synthesis of methyl Ethyl Ketone Azide in 1-Ethyl-3-methylimidazolium acetate Ionic liquid

Cyanoacetamide (3g, 35.7mmol), 1-ethyl-3-methylimidazolyl acetate (10ml), sodium hexametaphosphate (0.3g, 0.5mmol), acetonitrile (6.80ml, 200mmol), 28% (by mass) aqueous ammonia (25ml, 294mmol), butanone (27ml, 294mmol) were added in this order to a l00ml three-necked round-bottomed flask equipped with a thermometer and a condenser, hydrogen peroxide (10ml, 98mmol) was added dropwise, the mixture was stirred at 80 ℃ for 5 hours, the reaction mixture was distilled, aqueous ammonia, butanone, acetonitrile, 2-butanol, and water were distilled off, and the remaining solution was extracted with toluene to recover an ionic liquid, whereby 11.45g of a product was obtained in 84.14% yield (based on hydrogen peroxide).

Claims

1. A method for synthesizing methyl ethyl ketazine comprises the following steps: and (3) performing synthetic reaction on ammonia, hydrogen peroxide and methyl ethyl ketone in a working solution containing a catalyst and an ionic liquid at the temperature of 20-100 ℃, and performing post-treatment to obtain a product.

2. The method of claim 1, wherein the ionic liquid is one of the following: the alkyl imidazole tetrafluoroborate, the alkyl imidazole hexafluorophosphate, the alkyl imidazole acetate and the aromatic imidazole tetrafluoroborate, wherein the alkyl contains 1-10 carbon atoms.

3. The method of claim 2, wherein the ionic liquid is one of the following: 1-butyl-3-methylimidazole tetrafluoroborate, 1-butyl-3-methylimidazole acetate and benzyl imidazole tetrafluoroborate.

4. The method for synthesizing methyl ethyl ketazine as recited in claim 1, characterized in that said catalyst is one or a mixture of more than one of the following: amides, imines, amine salts, arsenic compounds, nitriles.

5. The method of claim 4, wherein the catalyst is one or a mixture of the following: cyanoacetamide, acetonitrile.

6. The method for synthesizing methyl ethyl ketazine as recited in claim 1, wherein the working solution is further added with a hydrogen peroxide stabilizer, and the concentration of the hydrogen peroxide stabilizer in the working solution is 10-1000 ppm.

7. The method for synthesizing methyl ethyl ketazine as recited in claim 6, wherein the stabilizer is sodium hexametaphosphate, and the concentration of the stabilizer in the working solution is 50-250 ppm.

8. The method for synthesizing methyl ethyl ketone azine according to any one of claims 1 to 7, wherein the molar ratio of hydrogen peroxide, methyl ethyl ketone, ammonia, ionic liquid, and catalyst is 1: 0.2 to 5: 1 to 10: 0.5 to 3: 1 to 5.

9. The method for synthesizing methyl ethyl ketone azine according to claim 8, wherein the catalyst is a mixture of acetonitrile and cyanoacetamide, and the molar ratio of hydrogen peroxide, methyl ethyl ketone, ammonia, ionic liquid, acetonitrile and cyanoacetamide is 1: 1.5-4: 1-2: 1-4: 0.2-0.6; the synthesis reaction temperature is 30-70 ℃, and the reaction time is 1-8 h.

10. The method of claim 8, wherein the synthesis is carried out under ultrasonic irradiation.