CN105218368A - A kind of method of ionic liquid-catalyzed synthesis Momo-cyclohexyl fumarte - Google Patents

Abstract

The invention belongs to the field of chemical synthesis, and in particular relates to a method for catalyzing and synthesizing monocyclohexyl fumarate by ionic liquid. The method uses maleic anhydride and cyclohexanol as raw materials, carries out esterification-isomerization reaction under the catalysis of an ionic liquid catalyst, and obtains required monocyclohexyl fumarate. The method for preparing monocyclohexyl fumarate described in the present invention first tries to apply ionic liquid catalyst in the synthetic experiment of monocyclohexyl fumarate, with maleic anhydride and cyclohexanol as raw material, catalyzed in ionic liquid catalyst The esterification-isomerization reaction can be carried out under the same reactor, and one-step reaction can be realized through one feed, the whole reaction does not need secondary feed, and the reaction time is shorter (less than 4h), compared with the existing In other one-step synthetic reactions in the prior art, the product yield of the method of the present invention can reach more than 80%, and the product yield is greatly improved.

Description

A kind of method of ionic liquid catalytic synthesis monocyclohexyl fumarate

technical field

The invention belongs to the field of chemical synthesis, and in particular relates to a method for catalyzing and synthesizing monocyclohexyl fumarate by ionic liquid.

Background technique

At present, the food preservatives actually used at home and abroad are mainly benzoic acid, sorbic acid and its salts, and paraben preservatives, etc., but their effects are affected by factors such as microbial species, food ingredients, pH value and solubility. influence, which limits their applications to a large extent. Fumarate preservatives are new products widely used at present, and have attracted widespread attention because of their characteristics of broad spectrum, high efficiency, low toxicity, economical and practical. Dimethyl fumarate was once considered to be the most promising chemical preservative, widely used in food, leather, feed and other industries. However, dimethyl fumarate has a strong stimulating effect on the skin and mucous membranes, can cause allergic reactions, and limits its further application. People have turned their attention to the development and research of preservatives based on fumaric acid. .

Fumaric acid monoester is an important class of organic synthesis intermediates and new chemical preservatives, and is favored for its advantages of low toxicity, high efficiency, use not limited by pH value, and no residue. Among them, monocyclohexyl fumarate (momo-cyclohexylfumarte, MCHF) can be used as a crosslinking agent for various polymers, especially in fields that need to be cured in air, such as coatings, coatings, bonding and sealing material, and because it contains a carboxyl group, it can be used to prepare some polymer compounds with specific properties. Therefore, MCHF is required by many European and American companies. The research on the antibacterial effect of monocyclohexyl fumarate also shows that it shows strong antibacterial activity at pH 3-9, much higher than that of dimethyl fumarate, and its antibacterial activity after high temperature treatment There is no obvious reduction in the ability; at the same time, the skin sensitivity test shows that monocyclohexyl fumarate is much less irritating and allergic to the skin than dimethyl fumarate. It can be seen that monocyclohexyl fumarate has completely solved the biggest obstacle encountered in the application process of dimethyl fumarate, and has great application prospects in food and fresh-keeping. It is a new type of high-efficiency preservative.

At present, the production of monocyclohexyl fumarate is very small in the world, and there are few studies on its synthesis reported in the literature. The traditional synthesis of fumarate is obtained by direct esterification of fumaric acid and alcohol with inorganic acid as a catalyst. Although this synthesis method has the advantages of simple operation and high product yield, the disadvantage is that the by-product fumarate The existence of a large number of acid diesters increases the difficulty of post-processing, and the equipment is severely corroded and the price of raw materials is high. At present, many documents have reported the improved two-step one-pot method of synthesizing monocyclohexyl fumarate, that is, using maleic anhydride and cyclohexanol as raw materials, first generating monocyclohexyl maleate through esterification, and then Synthesize monocyclohexyl fumarate through isomerization under the action of catalyst. In this process, due to the steric hindrance effect, the side reaction of forming the maleic acid diester is difficult to occur, and the source of maleic anhydride is wide, the price is low, and good results have been achieved. However, although this method is carried out in the same reactor, the catalyst must be added again separately, that is, the two-step method is prepared. Although the product yield is better, the reaction process is more complicated.

On this basis, Yan Peng et al reported a method for the synthesis of monocyclohexyl fumarate using solid superacid as a catalyst. It uses solid superacid SO ₄ ^2- /SnO ₂ -CeO ₂ as a catalyst, and utilizes solid superacid to show high reactivity and selectivity for isomerization and esterification in acid-catalyzed reactions. Complete the process of esterification and isomerization, and the yield of monocyclohexyl fumarate product can reach 57.65%, although the product yield is slightly lower than the aforementioned two-step one-pot method, but it is a one-step synthesis of fumarate The further study of acid monocyclohexyl ester has laid a foundation, but the yield of its target product is still low. Subsequently, it was reported in the literature that the yield of monocyclohexyl fumarate can reach 76.61% by using SO ₄ ^2- /SnO ₂ -Al ₂ O ₃ as a catalyst, which is still not ideal although it has been improved.

Contents of the invention

For this reason, the technical problem to be solved by the present invention is to provide a kind of method of the synthetic monocyclohexyl fumarate that reaction process is simple and product yield is high.

In order to solve the problems of the technologies described above, the method of ionic liquid catalyzed synthesis of monocyclohexyl fumarate of the present invention is to take maleic anhydride and cyclohexanol as raw materials, and carry out esterification-isomerization under ionic liquid catalyst catalysis Reaction, makes required monocyclohexyl fumarate, and described reaction equation is as follows:

Preferably, the ionic liquid catalyst is 1-methyl-3-propanesulfonic acid imidazolium bisulfate ionic liquid catalyst.

The reaction temperature of the reaction is 80-100°C, and the reaction time is 2-4h.

In the reaction raw materials, the molar ratio of cyclohexanol to maleic anhydride is 1-2:1.

The catalyst is used in an amount of 10-20 wt% of the total amount of the cyclohexanol and maleic anhydride raw materials.

Most optimally, the reaction temperature of described reaction is 90 DEG C, and reaction time is 3.53h, and the mol ratio of described cyclohexanol and maleic anhydride is 1.62:1, and the consumption of described catalyst accounts for described cyclohexanol and maleic anhydride raw material 15.4 wt% of the total.

The reaction is carried out with the assistance of ultrasonic waves, the frequency of the ultrasonic treatment is 20-30 kHz, and the power is 200 mW/cm ² .

The ultrasonic treatment method is as follows: at the beginning of the reaction, process at a frequency of 20 kHz for 15 minutes, and then rapidly increase the frequency to 30 kHz for 15 minutes; repeat the above-mentioned ultrasonic treatment cycle until the end of the reaction.

The method of the present invention also includes the step of separating and recovering the reaction product and the catalyst, specifically: after the reaction is completed, add absolute ethanol and mix evenly, and filter while hot and recover the catalyst; cool the obtained filtrate until there is a white needle-like substance suspend, filter out the insoluble matter, and dry in vacuum to obtain the monocyclohexyl fumarate product.

The ionic liquid catalyst 1-methyl-3-propanesulfonic acid imidazolium hydrogen sulfate is prepared by the following method: using 1,3-propane sultone and N-methylimidazole as raw materials, in the presence of ethyl acetate, Carry out the reaction at 60-80°C until a white precipitate is produced, filter the precipitate, wash with ethyl acetate, and dry to obtain 1-(3-sulfonic acid)propyl-3-methylimidazolium salt;

Dissolve the 1-(3-sulfonic acid)propyl-3-methylimidazolium salt in water, add concentrated sulfuric acid to react at 80-90°C, and then remove the water to obtain a light yellow viscous liquid product, which is 1 - Methyl-3-propanesulfonic acid imidazolium bisulfate ionic liquid catalyst.

Ionic Liquids (Ionic Liquids, ILs for short), also known as room temperature ionic liquids, are salt substances in an ionic state at room temperature. An environmentally friendly solvent that is widely used to replace volatile chemical solvents. 1-Methyl-3-propanesulfonic acid imidazole hydrogen sulfate is a known ionic liquid catalyst in the prior art, which is used in the synthesis reaction of lipids to overcome the existence of catalysts such as conventional solid acids. It has the disadvantages of strong corrosiveness, high equipment investment, many side reactions, polluting the environment, difficulty in recycling, and difficulty in separating the product from the reaction system.

The method for preparing monocyclohexyl fumarate described in the present invention first tries to apply ionic liquid catalyst in the synthetic experiment of monocyclohexyl fumarate, with maleic anhydride and cyclohexanol as raw material, catalyzed in ionic liquid catalyst The esterification-isomerization reaction can be carried out under the same reactor, and one-step reaction can be realized through one feed, the whole reaction does not need secondary feed, and the reaction time is shorter (less than 4h), compared with the existing In other one-step synthesis reactions in the prior art, the product yield of the method of the present invention can reach more than 80%, and the product yield is greatly improved.

The method of the present invention further utilizes the ultrasonic-assisted method to try to further shorten the time of the whole reaction and improve the yield of the product. The data show that the conventional ultrasonic treatment method is helpful to further improve the product yield of the reaction, while the method of the present invention Further optimization obtained the gradient-cycle ultrasonic treatment method, which greatly improved the yield of the monocyclohexyl fumarate product, and achieved unexpected technical effects.

Description of drawings

In order to make the content of the present invention more easily understood, the present invention will be further described in detail below according to the specific embodiments of the present invention and in conjunction with the accompanying drawings, wherein,

Fig. 1 is the infrared spectrogram of monocyclohexyl fumarate product of the present invention.

detailed description

The ionic liquid catalyst 1-methyl-3-propanesulfonic acid imidazolium bisulfate used in the following examples of the present invention is a product of the prior art, and only needs to be prepared according to the existing conventional method. In the following examples of the present invention The synthetic schematic diagram of the 1-methyl-3-propanesulfonic acid imidazolium bisulfate used is as follows, and is prepared according to the following steps:

Weigh 18.4g of 1,3-propane sultone, and measure 100mL of ethyl acetate into a three-necked flask, install a constant pressure dropping funnel, a magnetic stirrer and a reflux condenser, and heat up to 60°C in a water bath Slowly add 12.3g of N-methylimidazole, after the dropwise addition is completed, keep the system warm at 70-80°C for 2 hours until a white precipitate is produced; filter the system under reduced pressure, wash the filter cake with ethyl acetate, put Drying in an oven at 100°C, the resulting product is 1-(3-sulfonic acid)propyl-3-methylimidazolium salt (MIM-PS);

Weigh 20.4g of MIM-PS into a 250mL three-neck flask, add water to dissolve it completely, slowly add 6.1mL of concentrated sulfuric acid into the flask under magnetic stirring, after the addition is completed, heat up to 90°C in a water bath to continue the reaction for 2h, then use The moisture in the reaction system was removed by a rotary evaporator to obtain a light yellow viscous liquid product, which was the desired 1-methyl-3-propanesulfonic acid imidazolium bisulfate ionic liquid catalyst.

In the method for preparing monocyclohexyl fumarate described in following each embodiment, its reaction equation is as follows:

Example 1

Weigh 9.8g (0.1mol) of maleic anhydride, 10g (0.1mol) of cyclohexanol and 1.98g (10wt%) of the above-mentioned ionic liquid catalyst, add in a 250mL three-necked flask, and install experimental devices such as a reflux condenser and a thermometer , heated with magnetic stirring, and reacted at a controlled temperature of 80°C for 4h. After the reaction is complete, add 10 mL of absolute ethanol into the flask, stir, and filter while hot to recover the catalyst. The obtained filtrate was cooled and left to stand for 12 hours until a white needle-like substance was suspended, then filtered, and the filtered insoluble matter was taken and dried in a vacuum drying oven to obtain the product monocyclohexyl fumarate.

Example 2

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and temperature of reaction, time are all identical with embodiment 1, and its difference is only, whole reaction all handles under ultrasonic assisted condition, The frequency of the ultrasonic treatment is 20 kHz, and the power is 200 mW/cm ² .

Example 3

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and temperature of reaction, time are all identical with embodiment 1, and its difference is only, whole reaction all handles under ultrasonic assisted condition, The frequency of the ultrasonic treatment is 30 kHz, and the power is 200 mW/cm ² .

Example 4

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and temperature of reaction, time are all identical with embodiment 1, and its difference is only, whole reaction all handles under ultrasonic assisted condition, The ultrasonic treatment method is as follows: at the beginning of the reaction, process at a frequency of 20 kHz for 15 minutes, and then rapidly increase the frequency to 30 kHz for 15 minutes; repeat the above ultrasonic method for 8 cycles, and process until the end of the reaction.

Example 5

Weigh 9.8g (0.1mol) of maleic anhydride, 20g (0.2mol) of cyclohexanol and 2.98g (10wt%) of the above-mentioned ionic liquid catalyst, add in a 250mL three-necked flask, and install experimental devices such as a reflux condenser and a thermometer , heated with magnetic stirring, and reacted at a controlled temperature of 100°C for 2h. After the reaction is complete, add 10 mL of absolute ethanol into the flask, stir, and filter while hot to recover the catalyst. The obtained filtrate was cooled and left to stand for 12 hours until a white needle-like substance was suspended, then filtered, and the filtered insoluble matter was taken and dried in a vacuum drying oven to obtain the product monocyclohexyl fumarate.

Example 6

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and temperature of reaction, time are all identical with embodiment 5, and its difference is only, whole reaction is all processed under ultrasonic assisted condition, The frequency of the ultrasonic treatment is 20 kHz, and the power is 200 mW/cm ² .

Example 7

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and temperature of reaction, time are all identical with embodiment 5, and its difference is only, whole reaction is all processed under ultrasonic assisted condition, The frequency of the ultrasonic treatment is 30 kHz, and the power is 200 mW/cm ² .

Example 8

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and temperature of reaction, time are all identical with embodiment 5, and its difference is only, whole reaction is all processed under ultrasonic assisted condition, The ultrasonic treatment method is as follows: at the beginning of the reaction, process at a frequency of 20 kHz for 15 minutes, and then rapidly increase the frequency to 30 kHz for 15 minutes; repeat the above ultrasonic method for 8 cycles, and process until the end of the reaction.

Example 9

Weigh 9.8g (0.1mol) of maleic anhydride, 20g (0.2mol) of cyclohexanol and 2.98g (10wt%) of the above-mentioned ionic liquid catalyst, add in a 250mL three-necked flask, and install experimental devices such as a reflux condenser and a thermometer , heated with magnetic stirring, and reacted at a controlled temperature of 100°C for 2h. After the reaction is complete, add 10 mL of absolute ethanol into the flask, stir, and filter while hot to recover the catalyst. The obtained filtrate was cooled and left to stand for 12 hours until a white needle-like substance was suspended, then filtered, and the filtered insoluble matter was taken and dried in a vacuum drying oven to obtain the product monocyclohexyl fumarate.

Example 10

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and temperature of reaction, time are all identical with embodiment 9, and its difference is only, whole reaction all handles under ultrasonic assisted condition, The frequency of the ultrasonic treatment is 20 kHz, and the power is 200 mW/cm ² .

Example 11

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and temperature of reaction, time are all identical with embodiment 9, and its difference is only, whole reaction is all processed under ultrasonic assisted condition, The frequency of the ultrasonic treatment is 30 kHz, and the power is 200 mW/cm ² .

Example 12

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and temperature of reaction, time are all identical with embodiment 9, and its difference is only, whole reaction all handles under ultrasonic assisted condition, The ultrasonic treatment method is as follows: at the beginning of the reaction, process at a frequency of 20 kHz for 15 minutes, and then rapidly increase the frequency to 30 kHz for 15 minutes; repeat the above ultrasonic method for 8 cycles, and process until the end of the reaction.

Example 13

Weigh 9.8g (0.1mol) of maleic anhydride, 10g (0.1mol) of cyclohexanol and 3.96g (20wt%) of the above-mentioned ionic liquid catalyst, add in a 250mL three-necked flask, and install experimental devices such as a reflux condenser and a thermometer , heated with magnetic stirring, and reacted at a controlled temperature of 90°C for 2h. After the reaction is complete, add 10 mL of absolute ethanol into the flask, stir, and filter while hot to recover the catalyst. The obtained filtrate was cooled and left to stand for 12 hours until a white needle-like substance was suspended, then filtered, and the filtered insoluble matter was taken and dried in a vacuum drying oven to obtain the product monocyclohexyl fumarate.

Example 14

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and temperature of reaction, time are all identical with embodiment 13, and its difference is only, whole reaction is all processed under ultrasonic assisted condition, The frequency of the ultrasonic treatment is 20 kHz, and the power is 200 mW/cm ² .

Example 15

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and temperature of reaction, time are all identical with embodiment 13, and its difference is only, whole reaction is all processed under ultrasonic assisted condition, The frequency of the ultrasonic treatment is 30 kHz, and the power is 200 mW/cm ² .

Example 16

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and temperature of reaction, time are all identical with embodiment 13, and its difference is only, whole reaction is all processed under ultrasonic assisted condition, The ultrasonic treatment method is as follows: at the beginning of the reaction, process at a frequency of 20 kHz for 15 minutes, and then rapidly increase the frequency to 30 kHz for 15 minutes; repeat the above ultrasonic method for 8 cycles, and process until the end of the reaction.

Example 17

Weigh 9.8g (0.1mol) of maleic anhydride, 20g (0.2mol) of cyclohexanol and 5.96g (20wt%) of the above-mentioned ionic liquid catalyst, add in a 250mL three-necked flask, and install experimental devices such as a reflux condenser and a thermometer , heated with magnetic stirring, and reacted at a controlled temperature of 90°C for 4h. After the reaction is complete, add 10 mL of absolute ethanol into the flask, stir, and filter while hot to recover the catalyst. The obtained filtrate was cooled and left to stand for 12 hours until a white needle-like substance was suspended, then filtered, and the filtered insoluble matter was taken and dried in a vacuum drying oven to obtain the product monocyclohexyl fumarate.

Example 18

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and reaction temperature, time are all identical with embodiment 17, and its difference is only, whole reaction is all processed under ultrasonic assisted condition, The frequency of the ultrasonic treatment is 20 kHz, and the power is 200 mW/cm ² .

Example 19

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and reaction temperature, time are all identical with embodiment 17, and its difference is only, whole reaction is all processed under ultrasonic assisted condition, The frequency of the ultrasonic treatment is 30 kHz, and the power is 200 mW/cm ² .

Example 20

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and reaction temperature, time are all identical with embodiment 17, and its difference is only, whole reaction is all processed under ultrasonic assisted condition, The ultrasonic treatment method is as follows: at the beginning of the reaction, process at a frequency of 20 kHz for 15 minutes, and then rapidly increase the frequency to 30 kHz for 15 minutes; repeat the above ultrasonic method for 8 cycles, and process until the end of the reaction.

Example 21

Weigh 9.8g (0.1mol) of maleic anhydride, 16.2g (0.162mol) of cyclohexanol and 4g (15.4wt%) of the above-mentioned ionic liquid catalyst, add in a 250mL three-necked flask, install a reflux condenser, a thermometer and other experiments device, magnetic stirring and heating, and the reaction was carried out at a temperature of 90°C for 3.53 hours. After the reaction is complete, add 10 mL of absolute ethanol into the flask, stir, and filter while hot to recover the catalyst. The obtained filtrate was cooled and left to stand for 12 hours until a white needle-like substance was suspended, then filtered, and the filtered insoluble matter was taken and dried in a vacuum drying oven to obtain the product monocyclohexyl fumarate.

Example 22

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and reaction temperature, time are all identical with embodiment 17, and its difference is only, whole reaction is all processed under ultrasonic assisted condition, The frequency of the ultrasonic treatment is 20 kHz, and the power is 200 mW/cm ² .

Example 23

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and reaction temperature, time are all identical with embodiment 17, and its difference is only, whole reaction is all processed under ultrasonic assisted condition, The frequency of the ultrasonic treatment is 30 kHz, and the power is 200 mW/cm ² .

Example 24

The method for preparing monocyclohexyl fumarate described in this embodiment, its raw material and catalyst consumption, and reaction temperature, time are all identical with embodiment 17, and its difference is only, whole reaction is all processed under ultrasonic assisted condition, The ultrasonic treatment method is as follows: at the beginning of the reaction, process at a frequency of 20 kHz for 15 minutes, and then rapidly increase the frequency to 30 kHz for 15 minutes; repeat the above ultrasonic method for 8 cycles, and process until the end of the reaction.

Experimental example

1. GC-MS detection

The products prepared in the above Examples 1-24 were analyzed by GC-MS, and the chromatographic conditions were: RTX-5MS column (30.0m×0.25mm×0.25μm), inlet temperature 330°C, column temperature 100°C, The temperature was programmed to rise to 150°C at 6°C/min, held for 3 minutes, and then raised to 300°C at 9°C/min, and the ion source temperature was 250°C. The results of gas chromatography showed that the product had a high purity (≥99%).

Mass spectrometry results: m/z199 is the molecular ion peak (m+1), confirming that the synthesized product is monocyclohexyl ester; the ester product loses a hydroxyl group to generate a fragment ion m/z181, the product loses a carboxyl group to generate a fragment ion m/z153, and the product loses a ring The hexanol moiety generates a fragment ion m/z99.

2. FTIR Characterization Analysis

Utilize KBr crystal tablet (cm ^-1 ) to carry out infrared spectrum detection to the product prepared above, through comparative analysis, it can be seen that the product prepared according to the method of the present invention is monocyclohexyl fumarate, wherein Example 21 The infrared spectrogram of the product prepared in is shown in accompanying drawing 1. And because the mode of ultrasonic auxiliary treatment is only for accelerating the reaction, it does not affect the structure of the product, therefore, the method of the present invention can be used for the preparation of monocyclohexyl fumarate.

3. Detection of product yield

The product yield (product/reactant × 100%) of monocyclohexyl fumarate was detected for the products in the above-mentioned Examples 1-24 according to conventional methods in the prior art, and the detection results are shown in Table 1 below.

Each embodiment product yield situation of table 1

Numbering Product yield (%) Reaction time (h) Example 1 79.03 4 Example 2 80.46 4

Example 3 81.33 4 Example 4 88.27 4 Example 5 78.45 2 Example 6 80.75 2 Example 7 81.28 2 Example 8 88.85 2 Example 9 78.98 2 Example 10 80.39 2 Example 11 81.40 2 Example 12 88.68 2 Example 13 78.24 2 Example 14 81.01 2 Example 15 81.54 2 Example 16 88.96 2 Example 17 77.95 4 Example 18 81.03 4 Example 19 81.69 4 Example 20 88.73 4 Example 21 82.78 3.53 Example 22 85.98 3.53 Example 23 86.27 3.53 Example 24 93.35 3.53

Visible, the method for the present invention tries to apply ionic liquid catalyst in the synthetic experiment of monocyclohexyl fumarate for the first time, take maleic anhydride and cyclohexanol as raw material, carry out esterification-isomerization under the catalysis of ionic liquid catalyst Synthesis reaction, can be realized in the same reactor, through one-step feed to realize one-step reaction, the whole reaction does not need secondary feed, and the reaction time is shorter (less than 4h), compared with other one-step synthesis in the prior art reaction, the product yield of the method of the present invention can reach more than 80%, and the product yield is greatly improved.

The method of the present invention further utilizes the ultrasonic-assisted method to try to further shorten the time of the whole reaction and improve the yield of the product. The data show that the conventional ultrasonic treatment method is helpful to further improve the product yield of the reaction, while the method of the present invention Further optimization obtained the gradient-cycle ultrasonic treatment method, which greatly improved the yield of the monocyclohexyl fumarate product, and achieved unexpected technical effects.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. the method for an ionic liquid-catalyzed synthesis Momo-cyclohexyl fumarte, it is characterized in that, described method for raw material, carries out esterification-isomerization reaction with maleic anhydride and hexalin under ionic-liquid catalyst catalysis, obtained required Momo-cyclohexyl fumarte, described reaction equation is as follows:

2. the method for ionic liquid-catalyzed synthesis Momo-cyclohexyl fumarte according to claim 1, is characterized in that, described ionic-liquid catalyst is 1-methyl-3-N-morpholinopropanesulfonic acid imidazole bisulfate ionic-liquid catalyst.

3. the method for ionic liquid-catalyzed synthesis Momo-cyclohexyl fumarte according to claim 1 and 2, is characterized in that, the temperature of reaction of described reaction is 80-100 DEG C, reaction times 2-4h.

4., according to the method for the arbitrary described ionic liquid-catalyzed synthesis Momo-cyclohexyl fumarte of claim 1-3, it is characterized in that, in described reaction raw materials, the mol ratio of described hexalin and maleic anhydride is 1-2:1.

5., according to the method for the arbitrary described ionic liquid-catalyzed synthesis Momo-cyclohexyl fumarte of claim 1-4, it is characterized in that, the consumption of described catalyzer accounts for the 10-20wt% of described hexalin and maleic anhydride raw material total amount.

6. according to the method for the arbitrary described ionic liquid-catalyzed synthesis Momo-cyclohexyl fumarte of claim 1-5, it is characterized in that, the temperature of reaction of described reaction is 90 DEG C, reaction times 3.53h, the mol ratio of described hexalin and maleic anhydride is 1.62:1, and the consumption of described catalyzer accounts for the 15.4wt% of described hexalin and maleic anhydride raw material total amount.

7., according to the method for the arbitrary described ionic liquid-catalyzed synthesis Momo-cyclohexyl fumarte of claim 1-6, it is characterized in that, described reaction carries out under ultrasonic assistant, and the frequency of described ultrasonication is 20-30kHz, and power is 200mW/cm ².

8. the method for ionic liquid-catalyzed synthesis Momo-cyclohexyl fumarte according to claim 7, is characterized in that, described ultrasonication mode is: initial with 20kHz frequency processing 15min in reaction, rises to 30kHz frequency processing 15min fast subsequently; Repeat above-mentioned ultrasonic power circular treatment to reacting end.

9. according to the method for the arbitrary described ionic liquid-catalyzed synthesis Momo-cyclohexyl fumarte of claim 1-8, it is characterized in that, described method also comprises the step by reaction product and separation and recovery of catalyst, be specially: after question response, add dehydrated alcohol mixing, and filtered while hot reclaim catalyzer; Gained filtrate is cooled to adularescent acicular substance to suspend, leaches insolubles, through vacuum drying treatment, obtain described Momo-cyclohexyl fumarte product.

10. according to the method for the arbitrary described ionic liquid-catalyzed synthesis Momo-cyclohexyl fumarte of claim 2-9, it is characterized in that, described ionic-liquid catalyst 1-methyl-3-N-morpholinopropanesulfonic acid imidazole bisulfate is prepared by the following method: with 1,3-N-morpholinopropanesulfonic acid lactone and N-Methylimidazole are raw material, under ethyl acetate exists, carrying out reacting to producing white precipitate in 60-80 DEG C, leaching throw out and with ethyl acetate washing, oven dry, obtaining 1-(3-sulfonic group) propyl group-3-methylimidazole salt;

Described 1-(3-sulfonic group) propyl group-3-methylimidazole salt is dissolved in water, add the vitriol oil to react in 80-90 DEG C, remove moisture content subsequently and obtain faint yellow sticky shape product liquid, be 1-methyl-3-N-morpholinopropanesulfonic acid imidazole bisulfate ionic-liquid catalyst.