阅读说明：本技术 一种乙基己基甘油的制备方法 (Method for preparing ethylhexyl glycerol ) 是由 成西涛 沈寒晰 郭鹏涛 南蓉 彭逸峰 杨淑玮 白燕 于 2020-12-21 设计创作，主要内容包括：本发明公开了一种乙基己基甘油的制备方法,以异辛醇、3-氯-1,2-丙二醇和常用无机碱为原料,不添加相转移催化剂,通过一步反应制备出目标产物,再通过分离有机相及蒸馏等工艺步骤得到高纯度乙基己基甘油产品。本发明所述的制备方法具有工艺过程简单、反应条件温和、选择性高、能耗小、合成路线绿色、产品纯度高等特点,有利于乙基己基甘油在日化及化妆品等行业的推广使用。(The invention discloses a preparation method of ethylhexyl glycerin, which takes isooctyl alcohol, 3-chloro-1, 2-propanediol and common inorganic base as raw materials, does not add phase transfer catalyst, prepares a target product through one-step reaction, and obtains a high-purity ethylhexyl glycerin product through the process steps of separating an organic phase, distilling and the like. The preparation method has the characteristics of simple process, mild reaction conditions, high selectivity, low energy consumption, green synthetic route, high product purity and the like, and is favorable for popularization and application of the ethylhexyl glycerin in the industries of daily chemicals, cosmetics and the like.)

1. The method for preparing the ethylhexyl glycerin is characterized by comprising the following preparation steps: adding isooctyl alcohol and 3-chloro-1, 2-propylene glycol into a reactor according to the molar ratio of 1: 1.0-2.0, controlling the temperature of materials in the reactor to 20-80 ℃ under the stirring condition, dropwise adding 10-50% of inorganic alkali solution into the reactor, wherein the molar ratio of the addition amount of the inorganic alkali solution to the isooctyl alcohol is 1.0-1.5: 1, carrying out heat preservation reaction for 2-8 h, regulating the pH value to be neutral by using hydrochloric acid solution, cooling to 20 ℃, carrying out oil-water separation on the products by using a separating funnel, after discharging the water phase, washing the organic phase twice by using water, separating out the organic phase, distilling the organic phase components under the condition that the vacuum degree is 40-50 Pa by using molecular distillation equipment, collecting fractions at 138 +/-3 ℃ as products, and obtaining the ethylhexyl glycerol with the purity of more than or equal to 99%.

2. The method for producing ethylhexyl glycerin according to claim 1, wherein: the preferable molar ratio of the isooctyl alcohol and the 3-chloro-1, 2-propanediol added into the reactor is 1: 1.1-1.5.

3. The method for producing ethylhexyl glycerin according to claim 1, wherein: the inorganic alkali solution is an aqueous solution of sodium hydroxide or potassium hydroxide, the preferable concentration value of the inorganic alkali solution is 20-30%, and the preferable molar ratio of the addition amount of the inorganic alkali solution to isooctanol is 1.1-1.3: 1.

4. The method for producing ethylhexyl glycerin according to claim 1, wherein: the preferable reaction temperature of the materials in the reactor is 40-60 ℃, and the preferable reaction time for heat preservation is 3-5 h.

5. The method for producing ethylhexyl glycerin according to claim 1, wherein: the reactor is a three-mouth bottle provided with a spherical condenser and a thermometer.

Technical Field

The invention belongs to the technical field of fine chemical product preparation processes, and relates to a method for preparing ethylhexyl glycerol.

Background

Ethylhexyl glycerin (Ethylhexylglycerin) is an important representative variety of "additive-free" preservatives, and is a globally recognized multifunctional cosmetic additive today, and is widely used in various bath products, cleansing products, deodorants, eye make-up, foundations, hair care products, and sunscreen products. The ethylhexyl glycerin can improve the moisturizing effect of the formula of the emollient and the humectant and increase the smooth skin feel, can improve the absorption efficiency of the skin to the cream when being added into a cream system, and overcomes the defects of sticky skin feel, white skin feel and the like. The mixing of the ethylhexyl glycerin and the substance with antiseptic effect has synergistic effect, wherein the ethylhexyl glycerin is compatible with the traditional antiseptic, more than the ethylhexyl glycerin is matched with the polyalcohol to form an 'additive-free' antiseptic system, and the ethylhexyl glycerin can obviously improve the skin feeling of the cosmetics, increase the diffusion capacity of the fragrance and the like.

As a multifunctional assistant developed in recent years, the related synthesis process of the ethylhexyl glycerol is reported less at present. Chinese patent publication No. CN108191614A discloses a method for preparing ethylhexyl glycerol, which comprises: (1) taking boron trifluoride diethyl etherate solution as a catalyst, and stirring and reacting isooctyl alcohol and glycidyl ester at room temperature under the stirring condition to generate an intermediate; (2) adding acid serving as a catalyst into the intermediate obtained in the step (1), adding water or alcohol, and reacting under normal pressure or reduced pressure to hydrolyze or alcoholyze the intermediate obtained in the step (1); (3) and (3) washing the product obtained in the step (2) with water, separating the liquid, and distilling to obtain the ethylhexyl glycerol. The process needs boron trifluoride diethyl etherate and acid as catalysts, and has the defects of multiple reaction steps, complex process, difficult separation and environmental pollution. Chinese patent publication No. CN104817436A also discloses a method for preparing high-purity ethylhexyl glycerol, which comprises reacting 2-ethylhexyl glycidyl ester and acetone under boron trifluoride diethyl etherate catalysis to generate an intermediate 4-alkoxymethyl-1, 3-dioxoalkane, adding a terminating agent at appropriate time, hydrolyzing, separating, neutralizing with sodium bicarbonate, washing, adding a stabilizer, and performing short-path distillation to obtain ethylhexyl glycerol. The process needs to use 2-ethylhexyl glycidyl ester with higher cost as the initial raw material, so that the cost of the final product is overhigh, and the synthesis process has the defects of multiple processes, complex operation and the like. The defects limit the popularization and the application of the ethylhexyl glycerin as a novel multifunctional additive in the cosmetic and daily chemical industries to a great extent.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a method for preparing a target product, namely the ethylhexyl glycerol, by adopting isooctanol, inorganic base and 3-chloro-1, 2-propanediol which are easily available in the market as raw materials and adopting one-step reaction without adding a phase transfer catalyst.

The technical solutions adopted to achieve the above objects of the invention are as follows.

A method for preparing ethylhexyl glycerol comprises the following synthesis steps: adding isooctanol and 3-chloro-1, 2-propanediol into a reactor according to a molar ratio of 1: 1.0-2.0, controlling the temperature of materials in the reactor to 20-80 ℃ under the stirring condition, dropwise adding 10-50% of inorganic alkali solution into the reactor, wherein the molar ratio of the addition amount of the inorganic alkali solution to isooctanol is 1.0-1.5: 1, carrying out heat preservation reaction for 2-8 h, adjusting the pH value to be neutral (pH is 7) by using a hydrochloric acid solution, cooling to 20 ℃, carrying out oil-water separation on the product by using a separating funnel, washing the organic phase twice by using water after discharging the water phase, separating out the organic phase, distilling the organic phase component under the condition of 40-50 Pa by using molecular distillation equipment, collecting fractions at 138 +/-3 ℃ as products, and obtaining the ethylhexyl glycerol with the purity of more than or equal to 99%.

The further technical solution of the present invention further comprises: the preferable molar ratio of the isooctyl alcohol and the 3-chloro-1, 2-propanediol added into the reactor is 1: 1.1-1.5.

The further technical solution of the present invention further comprises: the inorganic alkali solution is an aqueous solution of sodium hydroxide or potassium hydroxide, the preferable concentration value of the inorganic alkali solution is 20-30%, and the preferable molar ratio of the addition amount of the inorganic alkali solution to isooctanol is 1.1-1.3: 1.

The further technical solution of the present invention further comprises: the preferable reaction temperature of the materials in the reactor is 40-60 ℃, and the preferable reaction time for heat preservation is 3-5 h.

The further technical solution of the present invention further comprises: the reactor is a three-mouth bottle provided with a spherical condenser and a thermometer.

Compared with the prior ethylhexyl glycerin preparation technology in the field, the invention has the beneficial effects that: isooctanol, 3-chloro-1, 2-propanediol and common inorganic base are used as raw materials, a phase transfer catalyst is not added, the target product ethylhexyl glycerol is prepared through one-step reaction, the process is simple, the synthesis yield and the product purity are high, the defects of more wastes, greater environmental pollution, complex process and the like in the prior art are avoided, and the method is suitable for industrial large-scale production. The method for preparing the ethylhexyl glycerin has the advantages of high yield, high product yield up to over 86%, high purity up to over 99.0%, colorless and transparent product appearance, no odor and superiority to similar products in the current market.

Drawings

FIG. 1 is an IR plot of ethylhexyl glycerol prepared according to one embodiment of the present invention (example 3).

FIG. 2 is a photograph of ethylhexyl glycerol prepared according to this example (example 3)¹HNMR map.

FIG. 3 is a GC plot of ethylhexyl glycerol prepared according to this example (example 3).

Detailed Description

The present invention will be further described with reference to the following examples.

Example 1

Adding 65g (0.5mol) of isooctanol and 60.8g (0.5mol) of 3-chloro-1, 2-propanediol into a 250ml three-neck flask provided with a spherical condenser and a thermometer, stirring, keeping the temperature to 20 ℃, dripping 112g (0.5mol) of potassium hydroxide aqueous solution with the content of 25% for 30min, keeping the temperature for reaction for 2h, stopping the reaction, adjusting the pH value to be neutral (the pH value is 7) by using a hydrochloric acid solution, performing oil-water separation on the product by using a separating funnel when the temperature is 20 ℃, discharging the aqueous phase, washing the organic phase twice by using 100ml of water, separating the organic phase, collecting fractions at the temperature of 138 +/-3 ℃ by using a molecular distillation device at the vacuum degree of 40-50 Pa, obtaining 58g of colorless transparent liquid-like ethylhexyl glycerol, and analyzing by using a gas chromatography, wherein the purity of the ethylhexyl glycerol is 99.0% and the yield is 56.9%.

Example 2

Adding 65g (0.5mol) of isooctanol and 60.8g (0.5mol) of 3-chloro-1, 2-propanediol into a 250ml three-necked flask provided with a spherical condenser and a thermometer, stirring, heating to 40 ℃, dripping 110g (0.55mol) of a 20% sodium hydroxide aqueous solution after 30min, keeping the temperature for reaction for 3h, stopping the reaction, adjusting the pH value to be neutral by using a hydrochloric acid solution, cooling to 20 ℃, performing oil-water separation on the product by using a separating funnel, discharging the aqueous phase, washing the organic phase twice by using 100ml of water, separating out the organic phase, collecting 138 +/-3 ℃ fraction by using a molecular distillation device at a vacuum degree of 40-50 Pa, obtaining 77.9g of colorless transparent liquid-like ethylhexyl glycerol, analyzing by using a gas chromatography, wherein the purity of the ethylhexyl glycerol is 99.1%, and the yield is 76.4%.

Example 3

Adding 65g (0.5mol) of isooctanol and 71.8g (0.65mol) of 3-chloro-1, 2-propanediol into a 250ml three-necked bottle provided with a spherical condenser and a thermometer, stirring, heating to 50 ℃, dripping 120g (0.6mol) of a 20% sodium hydroxide aqueous solution after 30min, keeping the temperature for reacting for 4h, stopping the reaction, adjusting the pH value to be neutral by using a hydrochloric acid solution, cooling to 20 ℃, performing oil-water separation on the product by using a separating funnel, discharging the aqueous phase, washing the organic phase twice by using 100ml of water, separating out the organic phase, collecting 138 +/-3 ℃ fraction by using a molecular distillation device at the vacuum degree of 40-50 Pa, obtaining 88g of colorless transparent liquid-like ethylhexyl glycerol, and analyzing by using a gas chromatography, wherein the purity of the ethylhexyl glycerol is 99.5%, and the yield is 86.3%.

Example 4

Adding 65g (0.5mol) of isooctanol and 99.45g (0.9mol) of 3-chloro-1, 2-propanediol into a 250ml three-necked bottle provided with a spherical condenser and a thermometer, stirring, heating to 80 ℃, dripping 105g (0.75mol) of potassium hydroxide aqueous solution with the content of 40% after 30min, keeping the temperature for reaction for 8h, stopping the reaction, regulating the pH value to be neutral by using a hydrochloric acid solution, cooling to 20 ℃, performing oil-water separation on the product by using a separating funnel, discharging the aqueous phase, washing the organic phase twice by using 100ml of water, separating out the organic phase, collecting fractions at the temperature of 138 +/-3 ℃ by using a molecular distillation device at the vacuum degree of 40-50 Pa, obtaining 71.7g of colorless transparent liquid-like ethylhexyl glycerol, analyzing by using a gas chromatography, wherein the purity of the ethylhexyl glycerol is 99.2%, and the yield is 70.3%.