阅读说明：本技术 酸性离子液体催化肉桂酸与苯甲醇反应制备肉桂酸苄酯的应用及制备肉桂酸苄酯的方法 (Application of acidic ionic liquid in catalyzing reaction of cinnamic acid and benzyl alcohol to prepare benzyl cinnamate and method for preparing benzyl cinnamate ) 是由 孙尚德 周燕霞 陈小威 田丽亚 余茜 于 2021-06-21 设计创作，主要内容包括：本发明提供了酸性离子液体催化肉桂酸与苯甲醇反应制备肉桂酸苄酯的应用及制备肉桂酸苄酯的方法,属于化学合成技术领域。本发明提供的方法包括以下步骤：将肉桂酸、苯甲醇与酸性离子液体混合,进行酯化反应,得到肉桂酸苄酯。本发明以酸性离子液体作为催化剂,能够有效催化肉桂酸和苯甲醇进行酯化反应,酸性离子液体毒性属于低毒物质,降低了对环境的污染；酸性离子液体相比于浓硫酸,能够大幅度降低对设备的腐蚀。实施例结果表明,本发明提供的方法肉桂酸苄酯的产率为56.3±2.5％～92.1±2.6％。(The invention provides an application of acidic ionic liquid in catalyzing reaction of cinnamic acid and benzyl alcohol to prepare benzyl cinnamate and a method for preparing benzyl cinnamate, and belongs to the technical field of chemical synthesis. The method provided by the invention comprises the following steps: mixing cinnamic acid, benzyl alcohol and acidic ionic liquid, and carrying out esterification reaction to obtain benzyl cinnamate. The invention takes the acidic ionic liquid as the catalyst, can effectively catalyze cinnamic acid and benzyl alcohol to carry out esterification reaction, and the toxicity of the acidic ionic liquid belongs to low-toxicity substances, thereby reducing the pollution to the environment; compared with concentrated sulfuric acid, the acidic ionic liquid can greatly reduce the corrosion to equipment. The results of the examples show that the yield of benzyl cinnamate in the method provided by the invention is 56.3 +/-2.5-92.1 +/-2.6%.)

1. The application of the acidic ionic liquid in catalyzing the reaction of cinnamic acid and benzyl alcohol to prepare benzyl cinnamate.

2. The use according to claim 1, wherein the cation of the acidic ionic liquid is one or more of 1-butylsulfonic acid-3-methylimidazolium ion, polysiloxane-3-methylimidazolium ion and amino acid methylimidazolium ion; the anion of the acidic ionic liquid is one or more of p-toluenesulfonate ion, trifluoromethanesulfonate ion, hydrogen sulfate ion and tetrafluoroborate ion.

3. The use according to claim 2, wherein the acidic ionic liquid is one or more of 1-butylsulfonic acid-3-methylimidazole p-toluenesulfonate, 1-butylsulfonic acid-3-methylimidazole trifluoromethanesulfonate, 1-butylsulfonic acid-3-methylimidazole hydrogensulfate, polysiloxane-3-methylimidazole tetrafluoroborate and amino acid methylimidazole hydrogensulfate.

4. A process for the preparation of benzyl cinnamate comprising the steps of:

mixing cinnamic acid, benzyl alcohol and acidic ionic liquid for esterification reaction to obtain benzyl cinnamate.

5. The method according to claim 4, wherein the cation of the acidic ionic liquid is one or more of 1-butylsulfonic acid-3-methylimidazolium ion, polysiloxane-3-methylimidazolium ion and amino acid methylimidazolium ion; the anion of the acidic ionic liquid is one or more of p-toluenesulfonate ion, trifluoromethanesulfonate ion, hydrogen sulfate ion and tetrafluoroborate ion.

6. The method according to claim 5, wherein the acidic ionic liquid is one or more of 1-butyl sulfonic acid-3-methylimidazole p-toluene sulfonate, 1-butyl sulfonic acid-3-methylimidazole trifluoromethanesulfonate, 1-butyl sulfonic acid-3-methylimidazole hydrogen sulfate, polysiloxane-3-methylimidazole tetrafluoroborate and amino acid methylimidazole hydrogen sulfate.

7. The method according to claim 4, wherein the molar ratio of the cinnamic acid to the benzyl alcohol is 1: 4-24.

8. The method according to claim 4, 6 or 7, wherein the mass of the acidic ionic liquid is 5-30% of the total mass of the cinnamic acid and the benzyl alcohol.

9. The method according to claim 4, wherein the esterification reaction is carried out at a temperature of 20 to 80 ℃ for 5 to 35 hours.

10. The method according to claim 4 or 9, wherein the mixing is oscillatory mixing at a rotation speed of 60 to 200 rpm.

Technical Field

The invention relates to the technical field of chemical synthesis, in particular to application of acidic ionic liquid in catalyzing reaction of cinnamic acid and benzyl alcohol to prepare benzyl cinnamate and a method for preparing benzyl cinnamate.

Background

Cinnamic acid (Cinnamic acid, CA) is an organic phenolic acid widely found in plants and is used as a fragrance and skin care product. However, cinnamic acid has limited its application due to its high melting point (133 ℃) and poor solubility in water. Benzyl cinnamate (Benzyl cinnamate) is one of cinnamic acid derivatives, has the fragrance peculiar to balsamic esters, has a low melting point (melting point of 34.5 ℃), has high solubility in water, and can be used as a substitute for cinnamic acid, and can be used as a flavoring agent and an antioxidant in the food, cosmetic and pharmaceutical industries.

Currently, the commonly used method for synthesizing benzyl cinnamate is as follows:

(1) diethylamine or triethylamine is used as a catalyst to catalyze sodium cinnamate and benzyl chloride to prepare benzyl cinnamate through esterification, but diethylamine and triethylamine have high toxicity and serious environmental pollution.

(2) Cinnamic acid and benzyl alcohol are used as raw materials, and concentrated sulfuric acid is used as a catalyst to carry out esterification reaction to synthesize benzyl cinnamate, but the concentrated sulfuric acid is corrosive to production equipment.

Therefore, the existing catalyst for preparing benzyl cinnamate has the defects of high toxicity or high corrosivity, which limits the practical application of the method.

Disclosure of Invention

In view of the above, the present invention aims to provide a method for preparing benzyl cinnamate by catalyzing a reaction between cinnamic acid and benzyl alcohol with an acidic ionic liquid. The invention uses acidic ionic liquid as catalyst, which reduces the pollution to environment and the corrosion to equipment.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides application of acidic ionic liquid in catalyzing reaction of cinnamic acid and benzyl alcohol to prepare benzyl cinnamate.

Preferably, the cation of the acidic ionic liquid is one or more of 1-butyl sulfonic acid-3-methylimidazole ion, polysiloxane-3-methylimidazole ion and amino acid methylimidazole ion; the anion of the acidic ionic liquid is one or more of p-toluenesulfonate ion, trifluoromethanesulfonate ion, hydrogen sulfate ion and tetrafluoroborate ion.

Preferably, the acidic ionic liquid is one or more of 1-butyl sulfonic acid-3-methylimidazole p-toluenesulfonate, 1-butyl sulfonic acid-3-methylimidazole trifluoromethanesulfonate, 1-butyl sulfonic acid-3-methylimidazole hydrogen sulfate, polysiloxane-3-methylimidazole tetrafluoroborate and amino acid methylimidazole hydrogen sulfate.

The invention provides a method for preparing benzyl cinnamate, which comprises the following steps:

mixing cinnamic acid, benzyl alcohol and acidic ionic liquid for esterification reaction to obtain benzyl cinnamate.

Preferably, the cation of the acidic ionic liquid is one or more of 1-butyl sulfonic acid-3-methylimidazole ion, polysiloxane-3-methylimidazole ion and amino acid methylimidazole ion; the anion of the acidic ionic liquid is one or more of p-toluenesulfonate ion, trifluoromethanesulfonate ion, hydrogen sulfate ion and tetrafluoroborate ion.

Preferably, the acidic ionic liquid is one or more of 1-butyl sulfonic acid-3-methylimidazole p-toluenesulfonate, 1-butyl sulfonic acid-3-methylimidazole trifluoromethanesulfonate, 1-butyl sulfonic acid-3-methylimidazole hydrogen sulfate, polysiloxane-3-methylimidazole tetrafluoroborate and amino acid methylimidazole hydrogen sulfate.

Preferably, the molar ratio of the cinnamic acid to the benzyl alcohol is 1: 4-24.

Preferably, the mass of the acidic ionic liquid is 5-30% of the total mass of the cinnamic acid and the benzyl alcohol.

Preferably, the esterification reaction is carried out at the temperature of 20-80 ℃ for 5-35 h.

Preferably, the mixing is oscillation mixing, and the rotation speed of the oscillation mixing is 60-200 rpm.

The invention provides application of acidic ionic liquid serving as a catalyst in catalyzing esterification reaction of cinnamic acid and benzyl alcohol to prepare benzyl cinnamate. The invention takes the acidic ionic liquid as the catalyst, can effectively catalyze cinnamic acid and benzyl alcohol to carry out esterification reaction, and the toxicity of the acidic ionic liquid belongs to low-toxicity substances, thereby reducing the pollution to the environment; compared with concentrated sulfuric acid, the acidic ionic liquid has lower acidity (the pH value of the acidic ionic liquid is between 1.95 and 2.13, and the pH value of the concentrated sulfuric acid is 0 to 1), and can greatly reduce the corrosion to equipment.

In the invention, the method for preparing benzyl cinnamate by catalyzing the reaction of cinnamic acid and benzyl alcohol with acidic ionic liquid comprises the following steps: mixing cinnamic acid, benzyl alcohol and acidic ionic liquid, and carrying out esterification reaction to obtain benzyl cinnamate. The acidic ionic liquid is used as a catalyst, so that the pollution to the environment and the corrosion to equipment are reduced, and the obtained benzyl cinnamate has high yield. The results of the examples show that the yield of benzyl cinnamate in the method provided by the invention is 56.3 +/-2.5-92.1 +/-2.6%.

Drawings

FIG. 1 is a reaction sequence of an esterification reaction;

FIG. 2 shows the results of HPLC analysis of the reaction product obtained in example 1.

Detailed Description

The invention provides application of acidic ionic liquid serving as a catalyst to catalyze reaction of cinnamic acid and benzyl alcohol to prepare benzyl cinnamate.

In the invention, the cation of the acidic ionic liquid is preferably one or more of 1-butyl sulfonic acid-3-methylimidazole ion, polysiloxane-3-methylimidazole ion and amino acid methylimidazole ion; the anion of the acidic ionic liquid is preferably one or more of p-toluenesulfonate ion, trifluoromethanesulfonate ion, hydrogen sulfate ion and tetrafluoroborate ion.

In the present invention, the acidic ionic liquid is preferably 1-butylsulfonic acid-3-methylimidazole p-toluenesulfonate ([ BSO)₃Hmim]TS), 1-Butylsulfonic acid-3-methylimidazolium trifluoromethanesulfonate ([ BSO ]₃Hmim]OTF), 1-Butylsulfonic acid-3-methylimidazolium hydrogen sulfate ([ BSO ]₃Hmim]HSO₄) Poly-silicon oxideAlkyl-3-methylimidazolium hydrogen sulfate ([ PSO ]₃Hmim]HSO₄) Polysiloxane-3-methylimidazolium tetrafluoroborate ([ PSO ]₃Hmim]BF₄) And the amino acid methyl imidazole hydrogen sulfate ([ AAHmim)]HSO₄) One or more of them. Specifically, when the acidic ionic liquid comprises a plurality of components, the acidic ionic liquid is preferably a mixture of 1-butyl sulfonic acid-3-methylimidazole p-toluene sulfonate and 1-butyl sulfonic acid-3-methylimidazole trifluoromethanesulfonate; or preferably a mixture of 1-butylsulfonic acid-3-methylimidazolium trifluoromethanesulfonate with polysiloxane-3-methylimidazolium hydrogen sulfate; or preferably a mixture of 1-butylsulfonic acid-3-methylimidazolium trifluoromethanesulfonate with polysiloxane-3-methylimidazolium tetrafluoroborate; or preferably a mixture of 1-butylsulfonic acid-3-methylimidazolium hydrogen sulfate and the amino acid methylimidazolium hydrogen sulfate. When the acidic ionic liquid comprises a plurality of components, the ratio of the amounts of the components is not particularly limited in the present invention.

The invention provides a method for preparing benzyl cinnamate, which comprises the following steps:

mixing cinnamic acid, benzyl alcohol and acidic ionic liquid, and carrying out esterification reaction to obtain benzyl cinnamate.

In the present invention, the acidic ionic liquid is preferably 1-sulfonic acid butyl-3-methylimidazole p-toluenesulfonate ([ BSO)₃Hmim]TS), 1-Butylsulfonic acid-3-methylimidazolium trifluoromethanesulfonate ([ BSO ]₃Hmim]OTF), 1-Butylsulfonic acid-3-methylimidazolium hydrogen sulfate ([ BSO ]₃Hmim]HSO₄) Polysiloxane-3-methylimidazolium hydrogen sulfate ([ PSO ]₃Hmim]HSO₄) Polysiloxane-3-methylimidazolium tetrafluoroborate ([ PSO ]₃Hmim]BF₄) And the amino acid methyl imidazole hydrogen sulfate ([ AAHmim)]HSO₄) One or more of them.

Specifically, when the acidic ionic liquid comprises a plurality of components, the acidic ionic liquid is preferably a mixture of 1-butyl sulfonic acid-3-methylimidazole p-toluene sulfonate and 1-butyl sulfonic acid-3-methylimidazole trifluoromethanesulfonate; or preferably a mixture of 1-butylsulfonic acid-3-methylimidazolium trifluoromethanesulfonate with polysiloxane-3-methylimidazolium hydrogen sulfate; or preferably a mixture of 1-butylsulfonic acid-3-methylimidazolium trifluoromethanesulfonate with polysiloxane-3-methylimidazolium tetrafluoroborate; or preferably a mixture of 1-butylsulfonic acid-3-methylimidazolium hydrogen sulfate and the amino acid methylimidazolium hydrogen sulfate. When the acidic ionic liquid comprises a plurality of components, the ratio of the amounts of the components is not particularly limited in the present invention.

In the invention, the molar ratio of the cinnamic acid to the benzyl alcohol is preferably 1: 4-24, more preferably 1: 8-20, even more preferably 1: 12-20, and most preferably 1: 20.

In the invention, the mass of the acidic ionic liquid is preferably 5-30%, more preferably 10-25%, and even more preferably 15-20% of the total mass of cinnamic acid and benzyl alcohol.

In the invention, the mixing is preferably oscillatory mixing, and the rotation speed of the oscillatory mixing is preferably 60-200 rpm, and more preferably 100-150 rpm. The present invention preferably uses an oscillator to perform the mixing.

In the invention, the temperature of the esterification reaction is preferably 20-80 ℃, more preferably 20-50 ℃, and further preferably 30-40 ℃; the esterification reaction time is preferably 5-35 h, more preferably 10-30 h, and further preferably 15-20 h.

Taking acidic ionic liquid 1-butyl sulfonic acid-3-methylimidazole trifluoromethanesulfonate as an example as a catalyst, the reaction process of the esterification reaction is shown in fig. 1 in the invention.

In FIG. 1, the acidic ionic liquid releases H⁺The carboxyl group of the side chain of cinnamic acid is composed of a ketone group and a hydroxyl group, and oxygen in the ketone group is negatively charged due to the difference of electronegativity, and H is released⁺Attacking carboxyl carbon atoms in the cinnamic acid to form carbenium ions; hydroxyl in the benzyl alcohol attacks carbonium ions in the cinnamic acid to form a tetrahedral intermediate; finally the tetrahedral intermediate loses one molecule of H₂O, liberation of H⁺Thereby forming benzyl cinnamate.

After the esterification reaction liquid is obtained, the esterification reaction liquid is preferably subjected to post-treatment, the post-treatment mode is preferably column chromatography separation, a chromatographic column for the column chromatography separation is preferably a C18 reverse phase column, a mobile phase preferably comprises an A phase and a B phase, the A phase is an acetic acid aqueous solution with the volume fraction of 0.5%, and the B phase is methanol.

The method for preparing benzyl cinnamate by catalyzing the reaction of cinnamic acid and benzyl alcohol with the acidic ionic liquid provided by the invention is described in detail below with reference to the examples, but the method is not to be construed as limiting the scope of the invention.

Example 1

In a 10mL round-bottom flask, cinnamic acid and benzyl alcohol were added in a molar ratio of 1:20, [ PSO ] in an amount of 10% by mass of the total amount of cinnamic acid and benzyl alcohol₃Hmim]BF₄The flask was set in a water bath constant temperature oscillator at 40 ℃ for reaction at 150 rpm. After 24h, 3. mu.L of the esterification reaction product was sampled and dissolved in a test tube with 3mL of chromatographic methanol, and filtered through a 0.45 μm organic filter, followed by High Performance Liquid Chromatography (HPLC), and the results were shown in FIG. 2. The yield of benzyl cinnamate in the esterification reaction product is 64.7 +/-2.1%.

Example 2

In a 10mL round-bottom flask, cinnamic acid and benzyl alcohol were added in a molar ratio of 1:20, [ BSO ] in an amount of 10% by mass of the total amount of cinnamic acid and benzyl alcohol₃Hmim]OTF, the flask was fixed in a water bath thermostat at 40 ℃ for reaction at 150 rpm. After 24h, 3. mu.L of the esterification reaction product was sampled in a test tube, dissolved in 3mL of chromatographic methanol, and filtered through a 0.45 μm organic filter, followed by detection by High Performance Liquid Chromatography (HPLC). The yield of benzyl cinnamate in the product is 79.5 +/-1.4%.

Example 3

In a 10mL round-bottom flask, cinnamic acid and benzyl alcohol were added in a molar ratio of 1:8, [ BSO ] in an amount of 10% by mass of the total amount of cinnamic acid and benzyl alcohol₃Hmim]OTF, the flask was fixed in a water bath thermostat at 40 ℃ for reaction at 150 rpm. After 24h, 3. mu.L of the esterification reaction product was sampled and dissolved in 3mL of chromatographic methanol, and filtered through a 0.45 μm organic filter, followed by HPLCAnd (5) detecting by using a chromatographic (HPLC). The yield of benzyl cinnamate in the product is 65.4 +/-2.4%.

Example 4

In a 10mL round-bottom flask, cinnamic acid and benzyl alcohol were added in a molar ratio of 1:12, [ BSO ] in an amount of 10% by mass of the total amount of the cinnamic acid and the benzyl alcohol₃Hmim]OTF, the flask was fixed in a water bath thermostat at 40 ℃ for reaction at 150 rpm. After 24h, 3. mu.L of the esterification reaction product was sampled in a test tube, dissolved in 3mL of chromatographic methanol, and filtered through a 0.45 μm organic filter, followed by detection by High Performance Liquid Chromatography (HPLC). The yield of benzyl cinnamate in the product is 67.5 +/-2.2%.

Example 5

In a 10mL round-bottom flask, cinnamic acid and benzyl alcohol were added in a molar ratio of 1:20, [ BSO ] in an amount of 10% by mass of the total amount of cinnamic acid and benzyl alcohol₃Hmim]TS, the flask was fixed in a water bath thermostat at 40 ℃ for reaction at 150 rpm. After 24h, 3. mu.L of the esterification reaction product was sampled in a test tube, dissolved in 3mL of chromatographic methanol, and filtered through a 0.45 μm organic filter, followed by detection by High Performance Liquid Chromatography (HPLC). The yield of benzyl cinnamate in the product is 73.1 +/-1.9%.

Example 6

In a 10mL round-bottom flask, cinnamic acid and benzyl alcohol were added in a molar ratio of 1:20, [ BSO ] in an amount of 10% by mass of the total amount of cinnamic acid and benzyl alcohol₃Hmim]HSO₄The flask was set in a water bath constant temperature oscillator at 40 ℃ for reaction at 150 rpm. After 24h, 3. mu.L of the esterification reaction product was sampled in a test tube, dissolved in 3mL of chromatographic methanol, and filtered through a 0.45 μm organic filter, followed by detection by High Performance Liquid Chromatography (HPLC). The yield of benzyl cinnamate in the product is 70.3 +/-2.6%.

Example 7

In a 10mL round-bottom flask, cinnamic acid and benzyl alcohol were added in a molar ratio of 1:20, [ PSO ] in an amount of 10% by mass of the total amount of cinnamic acid and benzyl alcohol₃Hmim]HSO₄The flask was set in a water bath constant temperature oscillator at 40 ℃ for reaction at 150 rpm. Sampling after 24h and producing esterification reaction productmu.L of the product was dissolved in 3mL of chromatographic methanol in a test tube, filtered through a 0.45 μm organic filter, and subjected to High Performance Liquid Chromatography (HPLC). The yield of benzyl cinnamate in the product is 77.2 +/-2.2%.

Example 8

In a 10mL round-bottom flask, cinnamic acid and benzyl alcohol were added in a molar ratio of 1:20, [ BSO ] in an amount of 5% by mass of the total amount of cinnamic acid and benzyl alcohol₃Hmim]OTF, the flask was fixed in a water bath thermostat at 40 ℃ for reaction at 150 rpm. After 24h, 3. mu.L of the esterification reaction product was sampled in a test tube, dissolved in 3mL of chromatographic methanol, and filtered through a 0.45 μm organic filter, followed by detection by High Performance Liquid Chromatography (HPLC). The yield of benzyl cinnamate in the product is 56.3 +/-2.5%.

Example 9

In a 10mL round-bottom flask, cinnamic acid and benzyl alcohol were added in a molar ratio of 1:20, [ BSO ] in an amount of 15% by mass of the total amount of cinnamic acid and benzyl alcohol₃Hmim]OTF, the flask was fixed in a water bath thermostat at 40 ℃ for reaction at 150 rpm. After 24h, 3. mu.L of the esterification reaction product was sampled in a test tube, dissolved in 3mL of chromatographic methanol, and filtered through a 0.45 μm organic filter, followed by detection by High Performance Liquid Chromatography (HPLC). The yield of benzyl cinnamate in the product is 85.2 +/-2.4%.

Example 10

In a 10mL round-bottom flask, cinnamic acid and benzyl alcohol were added in a molar ratio of 1:20, [ BSO ] in an amount of 15% by mass of the total amount of cinnamic acid and benzyl alcohol₃Hmim]OTF, the flask was set in a water bath thermostat at 50 ℃ for reaction at 150 rpm. After 24h, 3. mu.L of the esterification reaction product was sampled in a test tube, dissolved in 3mL of chromatographic methanol, and filtered through a 0.45 μm organic filter, followed by detection by High Performance Liquid Chromatography (HPLC). The yield of benzyl cinnamate in the product is 92.1 +/-2.1%.

Example 11

In a 10mL round-bottom flask, cinnamic acid and benzyl alcohol were added in a molar ratio of 1:20, [ BSO ] in an amount of 15% by mass of the total amount of cinnamic acid and benzyl alcohol₃Hmim]OTF, fixing the flaskThe reaction was carried out in a water bath constant temperature oscillator at 50 ℃ at a rotation speed of 60 rpm. After 24h, 3. mu.L of the esterification reaction product was sampled in a test tube, dissolved in 3mL of chromatographic methanol, and filtered through a 0.45 μm organic filter, followed by detection by High Performance Liquid Chromatography (HPLC). The yield of benzyl cinnamate in the product is 88.0 +/-2.0%.

Example 12

In a 10mL round-bottom flask, cinnamic acid and benzyl alcohol were added in a molar ratio of 1:20, [ BSO ] in an amount of 15% by mass of the total amount of cinnamic acid and benzyl alcohol₃Hmim]OTF, the flask was set in a water bath thermostat at 50 ℃ for reaction at 150 rpm. After 24h, 3. mu.L of the esterification reaction product was sampled in a test tube, dissolved in 3mL of chromatographic methanol, and filtered through a 0.45 μm organic filter, followed by detection by High Performance Liquid Chromatography (HPLC). The yield of benzyl cinnamate in the product is 92.1 +/-2.6%.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.