Guerbet-like alcohol, preparation method and application

Abstract

The invention provides Guerbet-like alcohol as well as a preparation method and application thereof, and relates to the field of organic synthesis. The molecular structural formula of the Guerbet-like alcohol is as follows: # imgabs0 #. According to the Guerbet-like alcohol, the preparation method and the application, the defects of the existing Guerbet alcohol can be overcome, the use of high-temperature and strong-basicity catalysts can be avoided in the preparation process, the process route is simple, and large-scale industrial production is facilitated; in addition, the low-temperature performance of the Guerbet alcohol can be further improved, and the application requirement for low-temperature lubrication of the Guerbet alcohol is effectively met.

Description

Technical Field

[0001] The present invention relates to the field of organic synthesis, and in particular to a kind of Guerbet-like alcohol, a preparation method and an application thereof. Background Art

[0002] Guerbet alcohol was initially discovered by chemist Marcel Guerbet in the 1890s. Its main characteristic is that there is a branched chain connected to the second carbon of the fatty alcohol, so it is also called 2-alkyl-1-alkanol. Guerbet alcohol is usually a kind of saturated primary alcohol, but it has different properties from straight-chain alcohols. For example, it is in a liquid state at room temperature, has higher lipophilicity than straight-chain alcohols with the same number of carbon atoms, and has good oxidation stability at high temperatures; at the same time, Guerbet alcohol also has good wetting performance, lubricating performance and permeation performance, as well as good biodegradability. The surfactants synthesized with Guerbet alcohol as the lipophilic group have some unique properties. For example, the Lutensol®TO series products developed by BASF in Germany have good emulsifying performance and very good compatibility with dyes, pigments, protective colloids, thickeners or other substances with molecular weights in the above range. They can also be formulated into acidic, alkaline and neutral detergents to meet different requirements. At present, such surfactants are widely used in many fields such as lubricating oils, cosmetics and textiles, and there are still many potential applications of Guerbet alcohol to be developed.

[0003] In the prior art, the chemical reaction for synthesizing Guerbet alcohol is called the Guerbet reaction, which is generally obtained by condensing and dimerizing two molecules of the raw material alcohol. During the Guerbet reaction process, it can be carried out in a liquid phase environment under normal pressure or under pressure, or in a gas phase environment. However, whether it is a liquid phase environment reaction or a gas phase environment reaction, the required reaction temperature is above 200°C, and the process route is cumbersome. It not only has strict requirements for production equipment, but also has high production energy consumption and low production efficiency, which is not conducive to large-scale industrial production; at the same time, during the Guerbet reaction process, the catalysts usually used are strong alkaline catalysts, such as sodium hydroxide, potassium hydroxide, strontium phosphate apatite (strontium hydroxyapatite), etc. These catalysts not only have strong corrosiveness, but also have side reactions and product pollution problems, and the post-treatment is complex, and the environmental friendliness is poor.

[0004] In addition, in the prior art, it is known that a variety of branched long-chain aldehydes and alcohols can be used as intermediates or raw materials to produce various other derivatives, and these derivatives can be used for many purposes. For example, as surfactants, textile chemicals, defoamers, wetting agents, etc., and also as petroleum additives, synthetic lubricants, plasticizers, solvents, etc. Among the various aforementioned uses, the potencies of known compounds vary, which depends on their chain length and structure, that is, the type of carbon chain and the degree of branching. However, in certain special uses (such as low-temperature lubrication uses, etc.), the long-chain alcohols and aldehydes and their derivatives known to date are not entirely satisfactory and all need to be further improved. Therefore, in view of the above technical problems, providing a novel-structured Guerbet alcohol-like, as well as the preparation method and application of the Guerbet alcohol-like, has important technical significance and research value. Summary of the Invention

[0005] To solve the technical problems existing in the prior art, the present invention provides a Guerbet alcohol-like, a preparation method and an application, which can overcome the defects existing in the existing Guerbet alcohol, can avoid using high temperature and strong alkaline catalysts during the preparation process, has a simple process route, is conducive to large-scale industrial production; and can further improve the low-temperature performance of the Guerbet alcohol-like, effectively meeting the application requirements for its low-temperature lubrication.

[0006] To solve the above technical problems, the technical solutions adopted by the present invention are as follows: A Guerbet alcohol-like, the molecular structural formula is as follows: 。

[0007] A preparation method of the aforementioned Guerbet alcohol-like, comprising the following steps: the first reaction, the second reaction, and the third reaction; The method of the first reaction is that in a solvent environment, in the presence of triethylamine, tetrahydrogeraniol reacts with methanesulfonyl chloride to obtain tetrahydrogeranyl methanesulfonate; The method of the second reaction is that in a solvent environment, after 3-allyloxy-1,2-propanediol is treated with sodium hydride, it reacts with tetrahydrogeranyl methanesulfonate to obtain 1-(3-(allyloxy)-2-((3,7-dimethyloctyl)oxy)propoxy)-3,7-dimethyloctane; The method of the third reaction is that in a solvent environment, under the catalysis of palladium-carbon catalyst and p-toluenesulfonic acid, 1-(3-(allyloxy)-2-((3,7-dimethyloctyl)oxy)propoxy)-3,7-dimethyloctane undergoes deallylation to obtain the Guerbet alcohol-like.

[0008] Preferably, in the first reaction, the molar ratio of tetrahydrogeraniol to methanesulfonyl chloride is 1:1 - 1.2; The molar amount of triethylamine is 0.8 - 2 times the molar amount of methanesulfonyl chloride.

[0009] Preferably, in the second reaction, the molar ratio of 3 - allyloxy - 1,2 - propanediol to tetrahydrogeranyl methanesulfonate is 1:2 - 2.5; The molar amount of sodium hydride is 2 - 2.5 times the molar amount of 3 - allyloxy - 1,2 - propanediol.

[0010] Preferably, in the third reaction, the weight ratio of 1-(3-(allyloxy)-2-((3,7 - dimethyloctyl)oxy)propoxy)-3,7 - dimethyloctane, palladium - carbon catalyst, and p - toluenesulfonic acid is 10 - 10.5:1:2 - 2.1.

[0011] Preferably, in the third reaction, the mass concentration of 1-(3-(allyloxy)-2-((3,7 - dimethyloctyl)oxy)propoxy)-3,7 - dimethyloctane in the solvent is 8 - 11 wt%; The solvent used is an ethanol - aqueous solution, and the volume concentration of ethanol in the solvent is 80 - 90%.

[0012] An application of the aforementioned gerb - type alcohol, which is used as a raw material for low - temperature lubricating oil.

[0013] A low - temperature lubricating oil is prepared by reacting the aforementioned gerb - type alcohol with isostearic acid.

[0014] Furthermore, the low - temperature lubricating oil is prepared by reacting the gerb - type alcohol with isostearic acid at a temperature of 160 - 170 °C until the acid value ≤ 1.5 mgKOH / g in the presence of a catalyst in an inert gas environment.

[0015] Preferably, the molar ratio of gerb - type alcohol to isostearic acid is 1:1 - 1.2.

[0016] Preferably, the catalyst is p - toluenesulfonic acid and sodium hypophosphite.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The gerb - type alcohol of the present invention can overcome the defects of the existing gerb - type alcohol, avoid using high temperature and strong - alkaline catalysts during the preparation process, has a simple process route, the raw materials are easy to obtain, the yield is high, and it is conducive to large - scale industrial production; meanwhile, the prepared gerb - type alcohol has stable properties, can further improve its low - temperature performance, and effectively meets the application requirements for its low - temperature lubrication.

[0018] (2)The low-temperature lubricating oil prepared from the Guerbet alcohol-like compound of the present invention has a freezing point ≤ -30°C and a viscosity ≥ 1600 mPa·s (at 25°C), and has good low-temperature performance. At the same time, after the low-temperature lubricating oil is kept at a constant temperature of 120°C for 48 hours, the acid value remains unchanged, indicating that the product also has good high-temperature stability. Description of the Drawings

[0019] Figure 1 1H NMR spectrum of 1-(3-(allyloxy)-2-((3,7-dimethyloctyl)oxy)propoxy)-3,7-dimethyloctane prepared in Example 2.

[0020] Figure 2 1H NMR spectrum of the Guerbet alcohol-like compound prepared in Example 3. Detailed Description of the Invention

[0021] In order to have a clearer understanding of the technical features, objectives, and effects of the present invention, the specific embodiments of the present invention will now be described. It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0022] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments of the present invention. As used herein, "first", "second", etc. are used to distinguish similar objects and are not used to describe a specific order or sequence. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] An embodiment of the present invention provides a Guerbet alcohol-like compound, and its molecular structural formula is shown as follows: .

[0024] The embodiment of the present invention also provides a preparation method of the Guerbet alcohol-like compound, including the following steps: the first reaction, the second reaction, and the third reaction.

[0025] The method of the first reaction is that in a solvent environment and in the presence of triethylamine, tetrahydrogeraniol reacts with methanesulfonyl chloride to obtain tetrahydrogeraniol methanesulfonate.

[0026] In the first reaction, the molar ratio of tetrahydrogeraniol to methanesulfonyl chloride is 1:1 - 1.2; The molar amount of triethylamine used is 0.8 - 2 times, preferably 0.9 - 1.1 times, the molar amount of methanesulfonyl chloride.

[0027] Specifically, for the first reaction, tetrahydrogeraniol and triethylamine are added to a solvent and dispersed evenly. Then, methanesulfonyl chloride is dropped in at a temperature of 0 - 5°C. After the addition of methanesulfonyl chloride is complete, the reaction is carried out at room temperature for 3 - 4 hours to obtain a reaction solution. After the reaction solution is neutralized and desolvated, the residue is dissolved in ethyl acetate and washed successively with deionized water and saturated brine, followed by drying and concentration to obtain tetrahydrogeraniol methanesulfonate.

[0028] The method for the second reaction is that in a solvent environment, 3 - allyloxy - 1,2 - propanediol is treated with sodium hydride and then reacts with tetrahydrogeraniol methanesulfonate to obtain 1 - (3 - (allyloxy) - 2 - ((3,7 - dimethyloctyl)oxy)propoxy) - 3,7 - dimethyloctane.

[0029] In the second reaction, the molar ratio of 3 - allyloxy - 1,2 - propanediol to tetrahydrogeraniol methanesulfonate is 1:2 - 2.5; The molar amount of sodium hydride used is 2 - 2.5 times the molar amount of 3 - allyloxy - 1,2 - propanediol.

[0030] Specifically, for the second reaction, 3 - allyloxy - 1,2 - propanediol is added to a solvent and dispersed evenly. Then, NaH is added under an ice - water bath condition. After reacting at room temperature for 2 - 3 hours, a toluene solution containing tetrahydrogeraniol methanesulfonate is dropped in. After the addition is complete, the reaction is carried out at 55 - 60°C for 6 - 7 hours to obtain a reaction solution. The residue after desolvating the reaction solution is dissolved in dichloroethane and washed successively with deionized water and saturated brine, followed by drying and concentration to obtain 1 - (3 - (allyloxy) - 2 - ((3,7 - dimethyloctyl)oxy)propoxy) - 3,7 - dimethyloctane.

[0031] The method for the third reaction is that in a solvent environment, under the catalysis of palladium - carbon catalyst and p - toluenesulfonic acid, 1 - (3 - (allyloxy) - 2 - ((3,7 - dimethyloctyl)oxy)propoxy) - 3,7 - dimethyloctane undergoes deallylation to obtain 2,3 - bis((3,7 - dimethyloctyl)oxy)propan - 1 - ol (i.e., pseudo - Guerbet alcohol).

[0032] In the third reaction, the mass concentration of 1 - (3 - (allyloxy) - 2 - ((3,7 - dimethyloctyl)oxy)propoxy) - 3,7 - dimethyloctane in the solvent is 8 - 11 wt%; The weight ratio of 1 - (3 - (allyloxy) - 2 - ((3,7 - dimethyloctyl)oxy)propoxy) - 3,7 - dimethyloctane, palladium - carbon catalyst, and p - toluenesulfonic acid is 10 - 10.5:1:2 - 2.1.

[0033] In the third reaction, the solvent used is an aqueous ethanol solution, and the volume concentration of ethanol in the solvent is 80 - 90%.

[0034] Specifically, for the third reaction, 1-(3-(allyloxy)-2-((3,7-dimethyloctyl)oxy)propoxy)-3,7-dimethyloctane, palladium carbon catalyst, p-toluenesulfonic acid, and a solvent are mixed evenly, heated to reflux, and kept refluxing for 20 - 24 h. After filtration and desolvation, 2,3-bis((3,7-dimethyloctyl)oxy)propan-1-ol, i.e., the pseudo-Guerbet alcohol, is obtained.

[0035] The embodiment of the present invention also provides the application of the aforementioned pseudo-Guerbet alcohol, which is used as a raw material for low-temperature lubricating oil.

[0036] The embodiment of the present invention also provides a low-temperature lubricating oil, which is prepared by reacting the aforementioned pseudo-Guerbet alcohol with isostearic acid.

[0037] Specifically, the preparation method of the low-temperature lubricating oil is as follows: in the presence of a catalyst and in an inert gas environment, the pseudo-Guerbet alcohol and isostearic acid are reacted at a temperature of 160 - 170 °C until the acid value ≤ 1.5 mgKOH / g; after washing, concentration, and deodorization, the low-temperature lubricating oil is obtained.

[0038] In the preparation of the low-temperature lubricating oil, the molar ratio of the pseudo-Guerbet alcohol to isostearic acid is 1:1 - 1.2; The catalyst is p-toluenesulfonic acid and sodium hypophosphite.

[0039] The following further illustrates the present invention in conjunction with some specific embodiments.

[0040] Example 1 This example provides the preparation of tetrahydrogeranyl methanesulfonate (i.e., the first reaction): The specific preparation process route is as follows:

[0041] The specific preparation process is as follows: At room temperature, tetrahydrogeraniol (554 mg, 3.5 mmol) and triethylamine (0.54 mL, 3.92 mmol) are dissolved in dichloromethane (7 mL), stirred evenly, cooled to 0 °C and kept warm, and methanesulfonyl chloride (304 μL, 3.92 mmol) is added dropwise. After the addition is completed in 5 min, the reaction mixture is raised to room temperature and stirred for 3.5 h; then 1 mol / L HCl aqueous solution (1 mL) is added, dichloromethane is removed under reduced pressure, the residue is dissolved in ethyl acetate (50 mL), washed successively with deionized water and saturated brine once each, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain a colorless oil, i.e., tetrahydrogeranyl methanesulfonate (800 mg, yield 97%).

[0042] The nuclear magnetic resonance test results of the tetrahydrogeranyl methanesulfonate prepared in this example are as follows: 1 H NMR (500 MHz, CDCl3) δ 4.25 (m, 2H), 3.01 (s, 3H), 1.78 (m, 1H), 1.61 - 1.48 (m, 3H), 1.33 - 1.10 (m, 6H), 0.93 (d, 3H), 0.87 (d, 6H).

[0043] Example 2 This example provides the preparation of 1-(3-(allyloxy)-2-((3,7-dimethyloctyl)oxy)propoxy)-3,7-dimethyloctane (i.e., the second reaction): The specific preparation process route is as follows:

[0044] The specific preparation process is as follows: Add 3-allyloxy-1,2-propanediol (3.0 mL, 23 mmol) to toluene (75 mL), add a NaH dispersion (concentration specification 60 wt%, 2.05 g, 53 mmol) under an ice-water bath, react at room temperature for 2 h, then dropwise add a toluene solution (80 mL) containing tetrahydrogeranyl methanesulfonate (11 g, 47 mmol). After the addition is complete, maintain the reaction at 60 °C for 6 h. After cooling, evaporate toluene under reduced pressure. Add dichloromethane (100 mL) to dissolve the residue, wash it once with deionized water and once with saturated brine in sequence, dry it with anhydrous sodium sulfate, and concentrate to obtain an oily substance, namely 1-(3-(allyloxy)-2-((3,7-dimethyloctyl)oxy)propoxy)-3,7-dimethyloctane (8.5 g, yield 90%).

[0045] The nuclear magnetic resonance test results of the 1-(3-(allyloxy)-2-((3,7-dimethyloctyl)oxy)propoxy)-3,7-dimethyloctane prepared in this example are as follows: 1 H NMR (500 MHz, CDCl3) δ 5.9 (m, 1H), 5.66 - 5.50 (m, 2H), 4.21 - 4.10 (m, 2H), 3.90 - 3.80 (m, 2H), 3.65 - 3.55 (m, 5H), 2.10 - 1.80 (m, 2H), 1.72 - 1.65 (m, 2H), 1.45 - 1.34 (m, 4H), 1.17 - 1.11 (m, 12H), 1.02 - 0.91 (m, 4H).

[0046] Example 3 This example provides the preparation of 2,3-bis((3,7-dimethyloctyl)oxy)propan-1-ol (i.e., gerbault alcohol) (i.e., the third reaction): The specific preparation process route is as follows:

[0047] The specific preparation process is as follows: To 1-(3-(allyloxy)-2-((3,7-dimethyloctyl)oxy)propoxy)-3,7-dimethyloctane (4.12 g, 10 mmol), add Pd / C catalyst (0.4 g), p-toluenesulfonic acid TsOH (0.8 g), methanol (40 mL), and water (8 mL). Heat to reflux, maintain the reflux reaction for 24 h, cool, and filter to recover the Pd / C catalyst. After removing the solvent by vacuum distillation, an oily substance is obtained, namely 2,3-bis((3,7-dimethyloctyl)oxy)propan-1-ol (3.2 g, yield 86%).

[0048] The nuclear magnetic resonance test results of the 2,3-bis((3,7-dimethyloctyl)oxy)propan-1-ol prepared in this example are as follows: 1 H NMR(500MHz,CDCl3) δ 3.89 (m, 1H), 3.56 (m, 4H), 3.33 (m, 5H), 1.78 (m,2H), 1.45 (m, 6H), 1.30 (m, 12H), 1.19 - 0.0.81 (m, 18H).

[0049] Example 4 This example provides the application of 2,3-bis((3,7-dimethyloctyl)oxy)propan-1-ol: React the said gerbault alcohol with isostearic acid to prepare a low-temperature lubricating oil. Specifically, put 2,3-bis((3,7-dimethyloctyl)oxy)propan-1-ol (142 g, 0.38 mol) prepared in Example 3, isostearic acid (by-product of dimerized oleic acid) (108 g, 0.38 mol), p-toluenesulfonic acid (1.5 g), and sodium hypophosphite (1 g) into a 1 L reaction flask equipped with a stirrer, thermometer, and gas inlet pipe. While introducing nitrogen, heat to 165 °C and maintain the reaction for 10 h. Stop the reaction when the acid value of the material ≤ 1.5 mgKOH / g; after the reaction is completed, wash the trace unreacted isostearic acid with a 5 wt% aqueous sodium hydroxide solution, concentrate the organic layer, and then perform steam deodorization under reduced pressure to obtain a light yellow oily liquid, namely the low-temperature lubricating oil (230 g, yield 95%).

[0050] After testing, the freezing point of the low-temperature lubricating oil prepared in this embodiment is ≤ -30°C, and the viscosity is ≥ 1600 mPa·s (25°C), showing good low-temperature performance. At the same time, when the low-temperature lubricating oil is placed in a temperature environment of 120°C and kept at a constant temperature for 48 hours, the acid value remains unchanged, indicating that the low-temperature lubricating oil also has good high-temperature stability.

[0051] Unless otherwise specified, the percentages used in the present invention are all mass percentages.

[0052] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A kind of Guerbet alcohol, characterized in that, The molecular structural formula is as follows: 。 2. A method for preparing a Gerb sterol-like alcohol as described in claim 1, characterized in that, It includes the following steps: The first reaction, the second reaction, and the third reaction; The method of the first reaction is that in a solvent environment, in the presence of triethylamine, tetrahydrogeraniol reacts with methanesulfonyl chloride to obtain tetrahydrogeranyl methanesulfonate; The method of the second reaction is that in a solvent environment, after 3-allyloxy-1,2-propanediol is treated with sodium hydride, it reacts with tetrahydrogeranyl methanesulfonate to obtain 1-(3-(allyloxy)-2-((3,7-dimethyloctyl)oxy)propoxy)-3,7-dimethyloctane; The method of the third reaction is that in a solvent environment, under the catalysis of palladium-carbon catalyst and p-toluenesulfonic acid, 1-(3-(allyloxy)-2-((3,7-dimethyloctyl)oxy)propoxy)-3,7-dimethyloctane undergoes deallylation to prepare geranylgeraniol-like alcohol.

3. The method for preparing Guerbet alcohols according to claim 2, characterized in that: In the first reaction, the molar ratio of tetrahydrogeraniol to methanesulfonyl chloride is 1:1 - 1.2; The molar amount of triethylamine used is 0.8 - 2 times the molar amount of methanesulfonyl chloride.

4. The method for preparing Guerbet alcohols according to claim 2, characterized in that: In the second reaction, the molar ratio of 3-allyloxy-1,2-propanediol to tetrahydrogeranyl methanesulfonate is 1:2 - 2.5; The molar amount of sodium hydride used is 2 - 2.5 times the molar amount of 3-allyloxy-1,2-propanediol.

5. The preparation method of the Guerbet alcohol according to claim 2, wherein In the third reaction, the weight ratio of 1-(3-(allyloxy)-2-((3,7-dimethyloctyl)oxy)propoxy)-3,7-dimethyloctane, palladium-carbon catalyst, and p-toluenesulfonic acid is 10 - 10.5:1:2 - 2.

1.

6. The method for preparing gerbertol according to claim 2, wherein In the third reaction, the mass concentration of 1-(3-(allyloxy)-2-((3,7-dimethyloctyl)oxy)propoxy)-3,7-dimethyloctane in the solvent is 8 - 11 wt%; The solvent used is an ethanol aqueous solution, and the volume concentration of ethanol in the solvent is 80 - 90%.

7. Use of a Gerburetol-like alcohol as described in claim 1, characterized in that, Use of the said geranylgeraniol-like alcohol as a raw material for low-temperature lubricating oil.

8. A low-temperature lubricating oil, characterized in that, It is prepared by reacting the geranylgeraniol-like alcohol described in claim 1 with isostearic acid.

9. The low-temperature lubricating oil according to claim 8, wherein, In the presence of a catalyst, in an inert gas environment, the said geranylgeraniol-like alcohol reacts with isostearic acid at a temperature of 160 - 170 °C until the acid value ≤ 1.5 mgKOH / g to obtain the product.

10. The low-temperature lubricating oil according to claim 8, characterized in that, The molar ratio of the said geranylgeraniol-like alcohol to isostearic acid is 1:1 - 1.2.

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