A kind of preparation method of octoxyglycerol

Abstract

The invention belongs to the technical field of organic synthesis, and specifically relates to a method for preparing octoxyglycerol. Octyl glycidyl ether is used as a raw material, and a hydrolysis reaction is carried out under acidic conditions and the action of a phase transfer catalyst to obtain octoxyglycerol. The preparation method of the invention is simple to operate, and no solvent is required in the whole process, and the safety is good, and the process is clean and environmentally friendly; at the same time, the target octoxyglycerol has high purity, high yield, and few side reactions, and has the advantages of safety, environmental protection, simple operation, large production capacity, low cost, easy to realize industrial production, etc., which is conducive to industrial application.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and particularly relates to a method for preparing octoxyglycerol. Background Art

[0002] Octoxyglycerol, also known as ethylhexylglycerol, glycerol monoisooctyl ether, etc. The CAS number is 70445-33-9, the chemical name is 3-[2-(ethylhexyl)oxy]-1,2-propylene glycol, 1,2-propylene glycol-3-(2-ethylhexyl) ether, etc., the English name is 3-[(2-Ethylhexyl)oxy]-1,2-propanediol, and the molecular formula is C 11 H 24 O3, chemical structure is as follows:

[0003]

[0004] Octoxyglycerol is a colorless to light yellow viscous transparent liquid with a mild odor. It is soluble in organic solvents such as alcohols, glycols and glycol ethers. Octoxyglycerol is a new multifunctional cosmetic additive with antibacterial, antiseptic, emollient and moisturizing effects. It has been widely used in the cosmetics field. As one of the most important representatives of "no added preservatives", this substance can effectively inhibit the growth of microorganisms, avoid the unpleasant odor produced by sebum in human sweat and shed epidermal cells under the action of Gram-positive bacteria, and does not affect the skin flora that is beneficial to humans. The combination with other traditional preservatives can significantly improve the bactericidal effect, significantly reduce the amount of traditional preservatives added, and thus reduce the toxicity of the preservative system in cosmetics and improve safety to the human body. At the same time, octoxyglycerol can improve the moisturizing and nourishing effects of the formula in the cream cosmetic system, and can also solve the shortcomings of the cream in terms of skin feel such as slow absorption, stickiness and whitening. It has a smooth skin feel and is safe and non-irritating. Not only in the cosmetics field, octoxyglycerol can also be used in the formulation of surfactant systems such as shampoo, shower gel, and daily chemical products such as deodorant products. It can be added to both the water phase and the oil phase, and is not affected by hydrolysis, temperature, and pH. In addition, octoxyglycerol can also be used as a surfactant in the formulation of cleaning agents for printed circuit board solder flux and as an additive for coatings and dyes.

[0005] Octoxyglycerol can be prepared by hydrolysis of octyl glycidyl ether, the reaction formula is as follows:

[0006]

[0007] Patent JP2003267901 uses p-toluenesulfonic acid monohydrate as a catalyst, and simultaneously feeds water and octyl glycidyl ether into a tubular reactor at 240°C for reaction. This method has a high reaction temperature and requires a tubular reactor. At the same time, the reaction process requires the addition of 100 to 500 times the amount of water as the substrate to obtain a good yield, resulting in a large amount of wastewater, causing environmental pollution.

[0008] Patent CN117447315 hydrolyzes octyl glycidyl ether in a mixture system consisting of an acid catalyst and a large amount of water-soluble organic solvent at 40-80°C to obtain octyloxyglycerol, with an acid concentration of 4.7-28.5%; the organic solvent includes N,N-dimethylformamide, dimethyl sulfoxide, acetonitrile, tetrahydrofuran, dioxane, acetone, etc. This method not only uses a high acid concentration, but also requires a large amount of water-soluble solvent to be added during the reaction. The recovery and treatment not only increases the complexity of the process, but also easily causes environmental pollution.

[0009] Patent JP7370339 discloses that octyl glycidyl ether, water, lauric acid and potassium hydroxide are first stirred in an autoclave at 140°C for 5 hours, then dehydrated under reduced pressure, lauric acid and potassium hydroxide are added, reacted at 160°C for 15 hours, and purified by reduced pressure distillation to obtain octoxyglycerol. This method is not only cumbersome to operate, but also has a yield of less than 50%.

[0010] Patent CN107216240 first reacts octyl glycidyl ether with acetic anhydride to prepare ester, and then hydrolyzes it under alkaline conditions to obtain octyloxyglycerol. However, this method introduces a large amount of acetic anhydride, and then a large amount of sodium acetate is produced as a by-product.

[0011] Therefore, the existing methods for preparing octoxyglycerol have the problems of high reaction temperature, high acid concentration used in the process, large amount of water-soluble solvent used, long reaction time, complicated operation, poor atom economy and easy to cause environmental pollution. Summary of the invention

[0012] The invention aims to provide a method for preparing octoxyglycerol which is simple to operate, safe, environmentally friendly, has good product quality, and uses low-cost and readily available raw materials and is suitable for industrial production.

[0013] To achieve the above object, the technical solution adopted by the present invention is:

[0014] A method for preparing octoxyglycerol: octyl glycidyl ether is used as a raw material and subjected to a hydrolysis reaction under acidic conditions and the action of a phase transfer catalyst to obtain octoxyglycerol;

[0015] The reaction formula is

[0016] Further, acid and phase transfer catalyst are added dropwise to octyl glycidyl ether; or octyl glycidyl ether is added dropwise to a system consisting of acid and phase transfer catalyst.

[0017] The acid is one or more of sulfuric acid, nitric acid, phosphoric acid, p-toluenesulfonic acid, and phosphotungstic acid.

[0018] The phase transfer catalyst is one or more of tetrapropylammonium bromide, tetrabutylammonium bromide, benzyltriethylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride or tetradecyltrimethylammonium chloride.

[0019] Preferably, it is one or more of tetrabutylammonium bromide, tetrabutylammonium chloride and benzyltriethylammonium chloride.

[0020] The concentration of the acid is 0.1-50% (w / w); the amount of the phase transfer catalyst is 0.5-10% (w / w) of the raw material octyl glycidyl ether, and the amount of the acid solution added is excessive relative to the raw material octyl glycidyl ether.

[0021] Preferably, the concentration of the acid is 0.5-5.0% (w / w); and the amount of the phase transfer catalyst is 1.0-5.0% (w / w) of the raw material octyl glycidyl ether.

[0022] The hydrolysis reaction temperature is 55-100° C., and the reaction time is 1-10 hours.

[0023] More preferably, the hydrolysis reaction temperature is 85-95° C. and the reaction time is 2-6 h.

[0024] The crude octoxyglycerol obtained by the hydrolysis reaction is purified by distillation to obtain high-content octoxyglycerol.

[0025] The crude octoxyglycerol product is purified by distillation and then subjected to reduced pressure distillation at a pressure of 45±5 Pa to obtain an octoxyglycerol product with a content of >99.0%.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The preparation method of the invention can obtain an octoxyglycerol product with a content of more than 99.0%.

[0028] The preparation method of the present invention is simple to operate, and no solvent needs to be added in the whole process, so the method has good safety, and the process is clean and environmentally friendly. Meanwhile, the target octoxyglycerol has high purity, high yield, and few side reactions, and has the advantages of safety, environmental protection, simple operation, large production capacity, low cost, and easy industrial production, so the method is conducive to industrial application. DETAILED DESCRIPTION

[0029] The present invention is further explained below in conjunction with the embodiments, but the scope of protection is not limited thereto. With reference to and using methods known to chemical technicians, such as optimization by changes in temperature, material ratio, etc., and replacement of phase transfer catalysts during hydrolysis, are all within the scope of this protection.

[0030] In the following examples, octyl glycidyl ether was obtained through commercial channels or prepared according to the method disclosed in JP7370339.

[0031] Example 1

[0032] Add 2.0 g of tetrabutylammonium bromide to 100 g of an aqueous solution with a sulfuric acid concentration of 1.0% (w / w), and then heat the system to 100°C. At this temperature, add 188.0 g (1.0 mol) of octyl glycidyl ether to the above system dropwise for 2.0 hours. After the addition is completed, the system is maintained at 100°C for 2.0 hours and the reaction progress is tracked by HPGC. After the raw material is <0.1%, it is cooled to room temperature, separated, and the oil phase is washed with 50 g of a 2% sodium bicarbonate aqueous solution, and the oil layer is separated again and distilled under reduced pressure: the 138-140°C fraction is received at a pressure of 45±5 Pa to obtain 195.6 g of octyloxyglycerol, with a content of 99.0% and a yield of 94.8%.

[0033] According to the preparation method of the above embodiment, by controlling different reaction conditions, other representative experiments are formed, see Table 1.

[0034] Table 1 Some representative test data.

[0035]

[0036]

[0037] Note: 1) * Weight ratio to raw material octyl glycidyl ether. 2) ** A represents octyl glycidyl ether added dropwise to a system consisting of acid, water and phase transfer catalyst; B represents a system consisting of acid, water and phase transfer catalyst added dropwise to octyl glycidyl ether; 3) *** The two can be mixed in any weight ratio.

[0038] In order to demonstrate that the present invention is suitable for industrial application, some conditions were scaled up for verification.

[0039] Example 16

[0040] Add 25kg of 5.0% aqueous sulfuric acid solution and 0.5kg of tetrabutylammonium bromide into a 150L reactor, and then heat the system to 95°C. Keep the system at 95°C, and add 46.8kg (0.25kmol) of octyl glycidyl ether to the above system, and the dropping time is 2.0 hours. After the dropping is completed, the system continues to maintain reflux at 95°C for 2.0 hours, and the HPGC analysis reaction is complete. Cool to room temperature, separate the layers, add 15kg of 2% sodium bicarbonate aqueous solution to the oil phase for washing, separate the oil layer again, and distill under reduced pressure: receive the 138-140°C fraction at a pressure of 45±5Pa to obtain 48.5kg of octyloxyglycerol, with a content of 99.1% and a yield of 94.2%.

[0041] Embodiment 17

[0042] Add 46.8kg (0.25kmol) of octyl glycidyl ether and 1.0kg of tetrabutylammonium chloride into a 150L reactor, then heat the system to 90°C, and keep this temperature to drop 25kg of mixed acid (nitric acid and sulfuric acid ratio is 1:1, w / w) with a content of 3.0% into the above system. The dropping time is 2.5 hours. After the dropping is completed, the system continues to maintain this temperature at 90°C for 4.0 hours, and the HPGC analysis reaction is completed. Cool to room temperature, separate the layers, add 10.0kg of 2% sodium bicarbonate aqueous solution to the oil phase for washing, separate the oil layer again, and distill under reduced pressure: receive the 138-140°C fraction at a pressure of 45±5Pa to obtain 48.8kg of octyloxyglycerol, with a content of 99.3% and a yield of 95.1%.

[0043] In order to better illustrate the present invention, a comparative experiment was conducted, and some experimental data are shown in Table 2.

[0044] Table 2 Part of comparative test data

[0045]

[0046] Note: 1) * Weight ratio to raw material octyl glycidyl ether. 2) ** A represents octyl glycidyl ether added dropwise to a system consisting of acid, water and phase transfer catalyst; B represents a system consisting of acid, water and phase transfer catalyst added dropwise to octyl glycidyl ether; 3) *** The two can be mixed in any weight ratio.

[0047] As can be seen from Tables 1 and 2, the reaction yield of Comparative Example 1 is reduced due to the low concentration of acid, the reaction cannot occur due to the low temperature in Comparative Example 2, the reaction yield of Comparative Example 3 is reduced due to the excessive amount of phase transfer catalyst added, and the reaction cannot proceed in Comparative Example 4 because no acid is added and acidic conditions cannot be provided. It can be seen that when the reaction conditions change, the content and yield of the product are significantly affected. Therefore, the embodiment of the present invention achieves the preparation of an octoxyglycerol product with a content of> 99.0% and a yield higher than 92% by controlling specific reaction conditions.

Claims

1. A method for preparing octoxyglycerol, characterized in that: Octyl glycidyl ether is used as a raw material and hydrolyzed under acidic conditions and with the action of a phase transfer catalyst to obtain octyloxyglycerol.

2. The method for preparing octoxyglycerol according to claim 1, characterized in that: Acid and phase transfer catalyst are added dropwise to octyl glycidyl ether; or octyl glycidyl ether is added dropwise to a system consisting of acid and phase transfer catalyst.

3. The method for preparing octoxyglycerol according to claim 1, characterized in that: The acid is one or more of sulfuric acid, nitric acid, phosphoric acid, p-toluenesulfonic acid, and phosphotungstic acid.

4. The method for preparing octoxyglycerol according to claim 1, characterized in that: The phase transfer catalyst is one or more of tetrapropylammonium bromide, tetrabutylammonium bromide, benzyltriethylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride or tetradecyltrimethylammonium chloride.

5. The method for preparing octoxyglycerol according to claim 1, characterized in that: The concentration of the acid is 0.1-50% (w / w); the dosage of the phase transfer catalyst is 0.5-10% (w / w) of the raw material octyl glycidyl ether.

6. The method for preparing octoxyglycerol according to claim 5, characterized in that: The concentration of the acid is 0.5-5.0% (w / w); the amount of the phase transfer catalyst is 1.0-5.0% (w / w) of the raw material octyl glycidyl ether.

7. The method for preparing octoxyglycerol according to claim 1, characterized in that: The hydrolysis reaction temperature is 55-100° C., and the reaction time is 1-10 hours.

8. The method for preparing octoxyglycerol according to claim 7, characterized in that: The hydrolysis reaction temperature is 85-95°C, and the reaction time is 2-6h.

9. The method for preparing octoxyglycerol according to claim 1, characterized in that: The crude octoxyglycerol obtained by the hydrolysis reaction is purified by distillation to obtain high-content octoxyglycerol.

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