CN101851159B - Method for synthetizing alcohol ester acetate by single step of ethyl acetate and alcohol ester exchange - Google Patents

Abstract

The invention discloses a method for synthetizing alcohol ester acetate by a single step of ethyl acetate and alcohol ester exchange, which relates to a synthesis method of the alcohol ester acetate. The method obtains a finished product by taking various alcohol ester acetates as raw materials, carbonate as a catalyst and ethyl acetate as an esterification reagent through single-step ester exchange reaction and concentration and purification. The invention has the characteristics of simple method, simple and convenient operation, energy source saving, low production cost, convenient popularization and application and the like, and diversified alcohol ester products with high yield and good quality can be prepared by adopting the method. The method can be widely applied to the industrial production of the alcohol ester acetate; the products prepared by adopting the method can be widely used as various flavor types of food essences and cosmetic essences, the essences of fancy soaps, washing powders and laundry detergents, the good solvents of dyes and printing ink and the like, and thereby, the demands of high amount due to wide market plane are satisfied.

Description

A kind of method of ethyl acetate and alcohol transesterification one-step synthetic alcohol acetate

technical field

The invention belongs to the technical field of organic chemistry synthesis, and in particular relates to a synthesis method of alcohol acetate.

Background technique

Alcohol acetate has been widely found as an important structural unit in natural products with biological activity, and many alcohol acetates have high application value, such as benzyl acetate, which has a unique aroma like jasmine, and is used to prepare apples, bananas, etc. , pineapple and other food flavors, and also used as an excellent solvent for alkyd resin, nitrocellulose, dyes, oils, and printing inks. Phenylethyl acetate is used in the preparation of scented soaps and daily cosmetics essences. It can be used as a substitute for methyl heptynoate. It has a peachy aroma and is also commonly used in the preparation of rose, orange blossom, violet, tuberose, briar and other essences. and fruity flavors. Lauryl acetate is a cheap raw material for ester waxy fragrance. It can be used as a solvent, diluent or mixture in low-grade flavor formulas. Because of its stable chemical properties and the composition of some natural essential oils, it has a relatively safe application Well, it is often used in edible flavors of citrus, coconut-based, fruity compounds, and dense fragrances, and it is also used as fragrances in flower-flavored roses and tuberose. Geranyl acetate is used to prepare rose, orange blossom, sweet-scented osmanthus and other types of essences, etc. It has a good market application prospect and a large demand.

There are many ways to synthesize esters. With the development of ester synthesis industry, transesterification has become a very important reaction in organic synthesis. Organic chemists can easily use this kind of reaction to synthesize the required esters. Since transesterification is a reversible process, many reported catalytic methods require the simultaneous removal of the alcohol produced by the reaction, thus requiring additional separation equipment. Existing methods for synthesizing alcohol acetate by transesterification, such as the patent No. 02136050.2 'method for preparing fatty alcohol acetate by transesterification of methyl acetate' patent, the disclosed method is to use methyl acetate and fatty alcohol as raw materials, through transesterification The reaction produces fatty alcohol acetate, and the catalyst used is sulfuric acid, p-toluenesulfonic acid or potassium hydrogensulfate. This method is very effective in the production of fatty alcohol acetate. The methanol produced is removed in time by evaporation, condensation, and extraction. At a sufficient level, improve the positive driving force of the transesterification reaction, but the method mainly has the following deficiencies:

(1) The esterification reagent that this method adopts is methyl acetate, and it is more expensive relative to ethyl acetate, has improved production cost.

(2) the method synthesizes the structure of ester and can only be acetic acid fatty alcohol class material, can not synthesize the alcohol acetate product of higher alcohol, cyclic alcohol, aromatic alcohol, enol etc. more than octyl alcohol, and scope of application is limited.

(3) The method adopts a timely extraction process to remove the methanol produced in the exchange process, and refluxes methyl acetate to enter the reaction system, which requires additional equipment and power, thereby further increasing the production cost.

(4) The method adopts a catalyst with strong acidity, which has a strong corrosion effect on equipment, relatively large environmental pollution, and high decontamination cost, which is inconvenient for popularization and application.

Contents of the invention

The purpose of the invention is to provide a kind of ethyl acetate and alcohol transesterification one-step synthetic method of alcohol acetate for the weak point of existing method for synthesizing alcohol acetate by transesterification. The method has the advantages of safe preparation and reaction production, not harsh process conditions, low requirements on production equipment, simple process, easy-to-obtain raw materials, low preparation cost, and the product basically does not contain harmful impurities, simple purification, and little environmental pollution.

Mechanism of the present invention: the present invention adopts common nontoxic, environment-friendly, and cheap ethyl acetate, and provides a simple, relatively green, clean, and economical new method for synthesizing new esters. Carbonate is used as a catalyst, it is relatively stable, cheap and easy to get.

Carbonate plays the role of a bifunctional catalyst in the catalytic process. The metal ion M ⁺ activates the ester group while the carbonate ion interacts with the proton of the alcoholic hydroxyl group to activate the alcohol. The activated alcoholic hydroxyl oxygen attacks the ester group to generate a proton. The nuclear substitution reaction generates a new alcohol ester and an ethanol molecule, and the carbonate is released to complete a catalytic cycle, and then enter the second step of the same catalytic cycle.

The technical scheme that realizes the object of the present invention is: a kind of method of ethyl acetate and alcohol transesterification one-step synthesizing alcohol acetate, with various alcohols as raw material, with carbonate as catalyst, with ethyl acetate as esterification reagent and double as The solvent is obtained through a simple process of one-step transesterification reaction, concentration and purification. Its specific method steps are as follows:

(1) transesterification reaction

Alcohol is used as raw material, carbonate (including alkali metal carbonates such as potassium carbonate or cesium carbonate) is used as catalyst, ethyl acetate is used as esterification reagent, and also as solvent, according to alcohol (mmol): carbonic acid Salt (mmol): the ratio of ethyl acetate (ml) is 1: (0.01～3): the ratio of (0.208～2.439), in reactor, add carbonate catalyst and ethyl acetate solvent earlier, under stirring, Then add alcohol, after the addition is completed, the temperature is raised to 85-205° C., and the transesterification is carried out with continuous stirring for 2-26 hours to prepare the alcohol acetate reaction solution.

The alcohols are aliphatic chain primary alcohols, aliphatic ring secondary alcohols, aromatic primary alcohols such as benzyl alcohol, aromatic secondary alcohols such as 1-phenylethyl alcohol or benzhydryl alcohol, allyl alcohols such as cinnamyl alcohol, geraniol One of.

(2) Concentrate and purify the product

After the (1) step was completed, the alcohol acetate reaction solution prepared in the (1) step was naturally cooled in the air, and the condensation system of the reactor was rinsed with dichloromethane, and the washing liquid was incorporated into the reaction solution in the reactor. . Then the mixed liquid in the reactor was concentrated by rotary evaporation, and the concentrated liquid and distillate were collected respectively. The distillate is ethyl acetate, which can be recycled. The concentrated solution is purified by silica gel column chromatography and eluted with the eluent. The effluent of the silica gel column chromatography is concentrated by rotary evaporation and drained to obtain the product.

The eluent is a mixture of ethyl acetate:petroleum ether with a volume ratio of 1:(70-100).

After the present invention adopts above-mentioned technical scheme, mainly have following effect:

(1) Alcohol raw materials have a wide range of sources and rich structures, and it is easy to obtain various functionalized alcohol esters, which can meet the demand for the diversity of ester types.

(2) Ethyl acetate is cheap and easy to obtain, the preparation process is simple, the toxicity is low, the pollution is small, it is beneficial to environmental protection, and can reduce the production cost, which is convenient for popularization and application.

(3) Catalyst carbonate is weakly alkaline, less corrosive to production equipment, less environmental pollution, cheap and easy to obtain, further reduces production costs, and is conducive to environmental protection requirements.

(4) The catalyst exhibits a heterogeneous catalytic effect during the catalytic process, which is convenient for separation and recovery, and can be used repeatedly. This not only makes full use of resources, but also reduces the emission of 'three wastes', which is conducive to environmental protection.

(5) The reaction conditions are mild and energy is saved; the synthesis operation is simple, without the need of anhydrous and oxygen-free conditions, and the post-treatment is simple; the cost is low, and it belongs to green production.

(6) The present invention only needs one-step transesterification and concentration and purification to obtain the finished product, and the yield is relatively high, and the ethanol produced does not need to be removed in time due to the influence of the chemical balance. The product quality is good, it is convenient for industrialized production, and it can meet the needs of a large market and a wide range.

The method of the invention can be widely applied to the industrialized production of alcohol acetate. The product prepared by the method of the present invention can be widely used as food flavors of various flavors, cosmetic flavors, soaps, washing powder, laundry detergent flavors and excellent solvents for dyes and inks, etc., to meet the needs of a wide range of markets and large quantities demand.

Detailed ways

The present invention will be further described below in combination with specific embodiments.

Example 1

A kind of ethyl acetate and alcohol transesterification one-step method for synthesizing alcohol acetate, its concrete steps are as follows:

(1) Taking geraniol as a raw material, using cesium carbonate as a catalyst, taking ethyl acetate as an esterification reagent, and also as a solvent, according to geraniol (mmol): cesium carbonate (mmol): ethyl acetate ( Milliliter) ratio is the ratio of 1:0.05:1, in reactor, add cesium carbonate (32.6mg, 0.1mmol) catalyst and ethyl acetate solvent (2.0mL) earlier, under stirring, then add geraniol (308.5mg , 2.0mmol), after the addition was completed, the temperature was raised to 125°C, and the transesterification was carried out with continuous stirring for 25 hours.

(2) After the (1) step was completed, the alcohol acetate reaction solution prepared in the (1) step was cooled naturally in the air, and the condensing system of the reactor was flushed with dichloromethane, and the washing liquid was incorporated into the reactor the reaction solution. Then concentrate the mixed solution in the reactor by rotary evaporation, collect the concentrated solution and the distillate respectively, the distillate is ethyl acetate, which can be recycled; the concentrated solution is purified by silica gel column chromatography, and eluted with the eluent, The effluent from the silica gel column chromatography was concentrated by rotary evaporation and sucked to dryness to obtain a colorless transparent liquid of geranyl acetate (373.0 mg, yield 95%).

The eluent is a mixture of ethyl acetate:petroleum ether with a volume ratio of 1:100.

Example 2

A kind of method that ethyl acetate and alcohol transesterification one-step synthetic alcohol acetate, its concrete steps are with embodiment 1, wherein:

In step (1), take phenylethyl alcohol as raw material, use cesium carbonate as catalyzer, take ethyl acetate as esterification reagent, and do solvent concurrently, according to phenylethyl alcohol (mmol): cesium carbonate (mmol): ethyl acetate (milliliters) ratio is 1:0.01:1 ratio, in reactor, add cesium carbonate (32.6mg, 0.1mmol) and ethyl acetate (10.0mL) first, then add phenethyl alcohol (1.2216g, 10.0mmol) under stirring ), continued to stir and carried out transesterification for 16 hours.

In step (2), the eluent was a mixture of ethyl acetate:petroleum ether with a volume ratio of 1:80 to obtain phenylethyl acetate (1.5382 g, yield 94%) as a colorless transparent liquid.

Example 3

A kind of method that ethyl acetate and alcohol transesterification one-step synthetic alcohol acetate, its concrete steps are with embodiment 1, wherein:

In step (1), take n-octanol as raw material, use cesium carbonate as catalyzer, take ethyl acetate as esterification reagent, and do solvent concurrently, according to n-octanol (mmol): cesium carbonate (mmol): acetic acid The ratio of ethyl ester (milliliter) is the ratio of 1:0.025:0.75, cesium carbonate (162.9mg, 0.5mmol) and ethyl acetate (15.0mL) are added earlier in the reactor, then add n-octanol (2.6046g , 20.0mmol), and continued stirring for 6 hours for transesterification.

In step (2), n-octyl acetate (3.1006 g, yield 90%) was obtained as a colorless transparent liquid.

Example 4

A kind of method that ethyl acetate and alcohol transesterification one-step synthetic alcohol acetate, its concrete steps are with embodiment 1, wherein:

In step (1), take benzyl alcohol as raw material, use salt of wormwood as catalyst, take ethyl acetate as esterification reagent, and do solvent concurrently, according to benzyl alcohol (mmol): potassium carbonate (mmol): ethyl acetate The ratio of (ml) is 1:0.15:1, first add potassium carbonate (41.5mg, 0.3mmol) and ethyl acetate (2.0mL) to the reactor, then add benzyl alcohol (207.9μL, 2.0mmol) under stirring ), and continued stirring to carry out transesterification for 10 hours.

In step (2), the volume ratio of eluent ethyl acetate:petroleum ether was 1:70 to obtain benzyl acetate (202.7 g, yield 67%) as a colorless transparent liquid.

Example 5

A kind of ethyl acetate and alcohol transesterification one-step method for synthesizing alcohol acetate, its amplified synthetic concrete steps are with embodiment 1, wherein:

In step (1), take benzyl alcohol as raw material, use salt of wormwood as catalyst, take ethyl acetate as esterification reagent, and do solvent concurrently, according to benzyl alcohol (mmol): potassium carbonate (mmol): ethyl acetate (ml) ratio is the ratio of 1:0.15:0.208, in reactor, add potassium carbonate (1.9938g, 14.4mmol) and ethyl acetate (20mL) earlier, then add benzyl alcohol (10.0mL, 96.2mmol) under stirring , and continued stirring for 13 hours for transesterification.

In step (2), the eluent was a mixture of ethyl acetate:petroleum ether with a volume ratio of 1:70 to obtain benzyl acetate (8.1791 g, yield 57%) as a colorless transparent liquid.

Example 6

A kind of method that ethyl acetate and alcohol transesterification one-step synthetic alcohol acetate, its concrete steps are with embodiment 1, wherein:

In step (1), take benzyl alcohol as raw material, use salt of wormwood as catalyst, take ethyl acetate as esterification reagent, and do solvent concurrently, according to benzyl alcohol (mmol): potassium carbonate (mmol): ethyl acetate (milliliters) ratio is the ratio of 1:3:1, in reactor, add potassium carbonate (829.3mg, 6mmol) earlier, reaction temperature is 85 ℃, keeps stirring and carries out transesterification for 2 hours.

In step (2), the eluent was a mixture of ethyl acetate:petroleum ether with a volume ratio of 1:70 to obtain benzyl acetate (30.0 mg, yield 10%) as a colorless transparent liquid.

Example 7

A kind of method that ethyl acetate and alcohol transesterification one-step synthetic alcohol acetate, its concrete steps are with embodiment 1, wherein:

In step (1), take benzyl alcohol as raw material, use salt of wormwood as catalyst, take ethyl acetate as esterification reagent, and do solvent concurrently, according to benzyl alcohol (mmol): potassium carbonate (mmol): ethyl acetate (milliliters) ratio is the ratio of 1:3:1, in reactor, add potassium carbonate (829.3mg, 6mmol) earlier, reaction temperature is 205 ℃, keep stirring and carry out transesterification for 2 hours.

In step (2), the eluent was a mixture of ethyl acetate:petroleum ether with a volume ratio of 1:70, and benzyl acetate (111.1 mg, yield 37%) was obtained as a colorless transparent liquid.

Example 8

A kind of method that ethyl acetate and alcohol transesterification one-step synthetic alcohol acetate, its concrete steps are with embodiment 1, wherein:

In step (1), take lauryl alcohol as raw material, use cesium carbonate as catalyst, take ethyl acetate as esterification reagent, and do solvent concurrently, according to lauryl alcohol (mmol): potassium carbonate (mmol): ethyl acetate (ml) ratio is the ratio of 1:0.01:1, cesium carbonate (32.6mg, 0.1mmol) and ethyl acetate (10mL) are added earlier in the reactor, then add lauryl alcohol (1.8633g, 10.0mmol) under stirring , the reaction temperature was 125°C, and the transesterification was carried out with continuous stirring for 26 hours.

In step (2), the eluent was a mixture of ethyl acetate:petroleum ether with a volume ratio of 1:100 to obtain a colorless transparent liquid lauryl acetate (1.8032g, yield 79%).

Example 9

A kind of method that ethyl acetate and alcohol transesterification one-step synthetic alcohol acetate, its concrete steps are with embodiment 1, wherein:

In step (1), take p-methyl benzyl alcohol as raw material, use salt of wormwood as catalyzer, take ethyl acetate as esterification reagent, and do solvent concurrently, according to p-methyl benzyl alcohol (mmol): wormwood carbonate (mmol) Mole): the ratio of ethyl acetate (ml) is the ratio of 1: 0.15: 2.439, first add potassium carbonate (17.0mg, 0.123mmol) and ethyl acetate (2mL) in the reactor, then add p-methyl acetate under stirring Benzyl alcohol (100.0mg, 0.82mmol), the reaction temperature was 125°C, and the transesterification was carried out with continuous stirring for 11 hours.

In step (2), the eluent was a mixture of ethyl acetate:petroleum ether with a volume ratio of 1:70 to obtain p-methylbenzyl acetate (71.4 mg, yield 53%) as a colorless transparent liquid.

Examples 10-18

A kind of concrete steps of the method for ethyl acetate and alcohol transesterification one-step synthetic alcohol acetate, with embodiment 1, wherein different parts are as shown in the table below.

Table 1

Claims (4)

1. a method for ethyl acetate and alcohol transesterification one-step synthetic alcohol acetate, is characterized in that concrete method step is as follows: (1) transesterification reaction Take alcohol as raw material, use potassium carbonate or cesium carbonate as catalyst, use ethyl acetate as esterification reagent, and also as solvent, according to alcohol millimole: carbonate millimole: ethyl acetate milliliter ratio is 1: (0.01 ～3): (0.208～2.439) ratio, first add carbonate catalyst and ethyl acetate solvent in the reactor, under stirring, then add alcohol, after adding, heat up to 85～205°C, continue stirring for transesterification 2 to 26 hours; The alcohols are aliphatic chain primary alcohols, aliphatic ring secondary alcohols, aromatic primary alcohols namely benzyl alcohol, aromatic secondary alcohols namely 1-phenylethyl alcohol or benzyl alcohol, allyl alcohols namely cinnamyl alcohol, geraniol one of (2) Concentrate and purify the product After the (1) step was completed, the alcohol acetate reaction solution prepared in the (1) step was naturally cooled in the air, and the condensation system of the reactor was rinsed with dichloromethane, and the washing liquid was incorporated into the reaction solution in the reactor. , and then concentrate the mixed solution in the reactor by rotary evaporation, collect the concentrated solution and distillate respectively; purify the concentrated solution by silica gel column chromatography, and elute with the eluent, and the effluent of the silica gel column chromatography is subjected to rotary evaporation Concentrate, drain; The eluent is a mixture of ethyl acetate:petroleum ether with a volume ratio of 1:(70-100). 2. according to the method for a kind of ethyl acetate described in claim 1 and alcohol transesterification one-step synthetic alcohol acetate, it is characterized in that: in step (1), raw material is geraniol, and catalyzer is cesium carbonate, geraniol Millimoles: cesium carbonate millimoles: ethyl acetate milliliter ratio is 1: 0.05: 1, warming up to 125 ° C, stirring for 10 hours for transesterification; In step (2), the eluent is a mixture of ethyl acetate:petroleum ether with a volume ratio of 1:100 to obtain a colorless transparent liquid geranyl acetate. 3. according to the method for a kind of ethyl acetate as claimed in claim 1 and alcohol transesterification one-step synthetic alcohol acetate, it is characterized in that: in step (1), raw material is phenylethyl alcohol, and catalyzer is cesium carbonate, phenylethyl alcohol millimoles : cesium carbonate millimoles: the ratio of ethyl acetate milliliter is 1: 0.01: 1, is warming up to 125 ℃, continues stirring and carries out transesterification 16 hours; In step (2), the eluent is a mixture of ethyl acetate:petroleum ether with a volume ratio of 1:80 to obtain phenylethyl acetate as a colorless transparent liquid. 4. according to the method for a kind of ethyl acetate and alcohol transesterification one-step synthetic alcohol acetate of claim 1, it is characterized in that: in step (1), raw material is n-octanol, and catalyzer is cesium carbonate, n-octanol Millimoles: millimoles of cesium carbonate: the ratio of milliliters of ethyl acetate is 1: 0.025: 0.75, the temperature is raised to 125 ° C, and the transesterification is carried out with continuous stirring for 6 hours; In step (2), the eluent is a mixture of ethyl acetate:petroleum ether with a volume ratio of 1:100 to obtain a colorless transparent liquid n-octyl acetate.