CN106928032A - A kind of preparation method of alkyl diether compound - Google Patents

Abstract

The application relates to the field of synthesis of alkyl diether compounds, and provides a preparation method of an alkyl diether compound with a structure shown as a formula (I), which comprises the following steps: in the presence of concentrated sulfuric acid, a glycol compound with a structure shown as a formula (II) and C₂-C₈Is contacted with the olefin. The alkyl diether compound prepared by the preparation method disclosed by the invention is high in purity, low in impurity content and simple in preparation process, and the concentrated sulfuric acid is used as a catalyst to replace the traditional sodium alkoxide synthesis method, so that the safety is high and the universality is strong.Wherein R is₁And R₂Each independently is C₁-C₈And R is alkyl of₁And R₂Not being methyl at the same time; r'₁Is hydrogen or C₁-C₈Alkyl group of (1).

Description

A kind of preparation method of alkyl diether compound

technical field

The invention relates to the field of synthesis of alkyl diether compounds, in particular to a preparation method of alkyl diether compounds.

Background technique

Alkyl diether compounds are an important class of compounds. They can not only be used as excellent solvents, but more importantly, they can be used as structural regulators for the synthesis of high 1,2-structure polybutadiene rubber from diene monomers, such as Butadiene rubber (BR), solution-polymerized styrene-butadiene rubber (SSBR), thermoplastic styrene-butadiene rubber (SBS) and other high 1,2-structure regulators, its regulation ability is stronger than fatty ether, tetrahydrofuran (THF), tertiary amine Lewis bases such as

The alkyl diether compound with the structure shown in formula (I) can efficiently adjust the microstructure of the polymer without affecting the active species, and the product coupling efficiency is high.

Wherein R and R can be methyl, ethyl, _{n -} propyl, isopropyl, n-butyl and tert-butyl.

The classic method of synthesizing such compounds is the Williamson synthesis method, which uses halogenated hydrocarbons and sodium alkoxides to obtain ethers containing different hydrocarbon groups through substitution reactions. Most of these reactions use anhydrous and oxygen-free systems, first using metal sodium or sodium hydride The alcohol is converted into sodium alkoxide, and then the corresponding haloalkane is added to the reaction system. The reaction conditions of this method are very demanding, and the operation is very dangerous and the cost is very high. The industrial use of sodium metal and organic solvents in large quantities will also cause serious pollution to the environment and endanger the health of operators. Therefore, there is an urgent need to develop a simple method for the preparation of alkyl diether compounds, so that the product yield is high and the purity is high, which can meet the requirements of the polymerization reaction.

Contents of the invention

The object of the present invention is to provide a kind of preparation method of the alkyl diether compound shown in formula (I), this method comprises: in the presence of concentrated sulfuric acid, the ethylene glycol with structure shown in formula (II) Contact reaction between compounds and C ₂ -C ₈ olefins;

Wherein, R ₁ and R ₂ are each independently a C ₁ -C ₈ alkyl group, and R ₁ and R ₂ are not methyl at the same time; R' ₁ is hydrogen or a C ₁ -C ₈ alkyl group.

The alkyl diether compound prepared by the preparation method of the invention has high purity and low impurity content, and can meet general industrial use as an additive. At the same time, the preparation process is simple, and concentrated sulfuric acid is used as a catalyst to replace the traditional sodium alkoxide synthesis method, which has high safety and strong universality, and can prepare a series of alkyl diether compounds with the structure shown in formula (I). In addition, the raw materials and catalysts used to prepare the target compound by using the method of the present invention are cheap, and have high industrial application prospects.

Other features and advantages of the present invention will be described in detail in the detailed description that follows.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, together with the following specific embodiments, are used to explain the present invention, but do not constitute a limitation to the present invention. In the attached picture:

Fig. 1 is the proton nuclear magnetic resonance spectrum figure of methoxyethyl tert-butyl ether in embodiment 1;

Fig. 2 is the carbon nuclear magnetic resonance spectrogram of methoxyethyl tert-butyl ether in embodiment 1;

Fig. 3 is the proton nuclear magnetic resonance spectrogram of ethoxy ethyl tert-butyl ether in embodiment 2;

Fig. 4 is the carbon nuclear magnetic resonance spectrogram of ethoxy ethyl tert-butyl ether in embodiment 2;

Fig. 5 is the proton nuclear magnetic resonance spectrogram of ethylene glycol di-tert-butyl ether in embodiment 3;

Fig. 6 is the carbon nuclear magnetic resonance spectrogram of ethylene glycol di-tert-butyl ether in embodiment 3.

detailed description

Specific embodiments of the present invention will be described in detail below. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

The present invention provides a method for preparing an alkyl diether compound having a structure as shown in formula (I), the method comprising: in the presence of concentrated sulfuric acid, the ethylene glycol compound having a structure as shown in formula (II) Contact reaction with C ₂ -C ₈ alkenes;

Wherein, R ₁ and R ₂ are each independently a C ₁ -C ₈ alkyl group, and R ₁ and R ₂ are not methyl at the same time; R' ₁ is hydrogen or a C ₁ -C ₈ alkyl group.

In a preferred case, R ₁ and R ₂ are each independently a C ₂ -C ₄ alkyl group, the C ₂ -C ₈ alkene is a C ₂ -C ₄ alkene, R' ₁ is hydrogen or C ₂ -C ₄ alkyl. Further preferably, R ₁ and R ₂ are each independently ethyl, isopropyl, sec-butyl or tert-butyl, and the C ₂ -C ₈ olefin is ethylene, propylene, 1-butene, 2-butene Alkene or isobutylene, _R'1 is hydrogen, ethyl, isopropyl, sec-butyl or tert-butyl.

In the present invention, the ethylene glycol compound with the structure shown in formula (II) can be ethylene glycol, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether and ethylene glycol monobutyl ether At least one, preferably, the ethylene glycol compound with the structure shown in formula (II) is ethylene glycol, ethylene glycol monoethyl ether, ethylene glycol isopropyl ether, ethylene glycol sec-butyl ether and ethylene glycol At least one of glycol tert-butyl ethers.

In the present invention, the molar ratio of the amount of the ethylene glycol compound represented by the formula (II) and the C ₂ -C ₈ olefin as the raw material is 0.1-0.5:1. In order to obtain a higher yield, preferably, the molar ratio of the amount of the ethylene glycol compound represented by the formula (II) to the C ₂ -C ₈ olefin is 0.15-0.3:1.

In the present invention, the amount of concentrated sulfuric acid is not particularly limited, and the weight ratio of the glycol compound with the structure shown in formula (II) to the amount of concentrated sulfuric acid can be 3-15:1. Preferably, in order to obtain a higher product yield and to facilitate subsequent treatment, the weight ratio of the ethylene glycol compound with the structure shown in formula (II) to concentrated sulfuric acid is 3-8:1.

In the present invention, in order to obtain a better reaction effect, the C ₂ -C ₈ olefin is passed into the reaction system in the form of gas. Wherein, the pressure of the C ₂ -C ₈ olefins may be 0.2-0.4 MPa. In the present invention, all pressures are gauge pressures.

In the present invention, the ethylene glycol compound having the structure represented by formula (II), C ₂ -C ₈ olefin and concentrated sulfuric acid can be mixed in a conventional manner in the art. In one embodiment, the mixing process of the ethylene glycol compound having the structure shown in formula (II), C ₂ -C ₈ olefins, and concentrated sulfuric acid may include: first mixing the structure shown in formula (II) The shown ethylene glycol compounds are uniformly mixed with concentrated sulfuric acid, and then C ₂ -C ₈ olefins are passed into the reaction system in the form of gas.

In the present invention, the conditions of the contact reaction are not particularly limited. For example, the conditions of the contact reaction include: the temperature may be 50-100° C., and the time may be 1.5-4 hours. In order to obtain higher yield and purity, preferably, the conditions of the contact reaction include: a temperature of 60-90° C., more preferably 70-80° C.; and a time of 2-3 hours.

In the present invention, the contact reaction can be performed in an inert atmosphere. The inert atmosphere can be provided by a protective gas, for example, the air in the reaction vessel can be replaced by the protective gas. The protective gas may be a conventional choice in the art, for example, may be selected from at least one of rare gases and nitrogen.

In the present invention, the preparation method may further include: after the contact reaction, cooling the reaction mixture to 20-40° C., and mixing the cooled mixture with a neutralizing agent.

In the present invention, the type of the neutralizing agent is not particularly limited, as long as it can neutralize the acidity of the mixture, for example, the neutralizing agent can be selected from at least A sort of. Preferably, the neutralizing agent is selected from at least one of NaOH, Ca(OH) ₂ and KOH. Further preferably, the neutralizing agent is NaOH.

The usage form of the neutralizing agent is not particularly limited. For example, the neutralizing agent may be used in a solid state or in an aqueous solution. When the neutralizing agent is used in the form of an aqueous solution, the concentration of the neutralizing agent solution can be conventionally selected in the art, for example, the concentration of the neutralizing agent can be 5%-50%.

In the present invention, the amount of the neutralizing agent is not particularly limited. Preferably, the pH value of the solution after the mixture is mixed with the neutralizing agent is 7-8.

In the present invention, the conditions for mixing the cooled reaction mixture and the neutralizing agent are not particularly limited, for example, the mixing conditions include: the time may be 10-20 minutes, and the temperature may be 0°C to 5°C. The mixing method can be a conventional choice in the art, for example, the solid neutralizing agent can be dissolved in ice water, and then mixed with the mixture under stirring at 0°C to 5°C; the neutralizing agent solution can also be cooled to 0°C to 5°C, and then mixed with the mixture under stirring.

The present invention has no special limitation on the treatment and purification methods after neutralization of the mixture, for example, extraction, distillation, rectification and other methods can be independently used for purification. According to a specific embodiment of the present invention, the purification is carried out according to the following method: after mixing the mixture with the neutralizing agent, use a separating funnel to separate the liquid, and dry the organic phase obtained by the liquid separation with anhydrous magnesium sulfate, The crude product is distilled out under atmospheric pressure, and the crude product is rectified to collect fractions with gas phase purity ≥ 98%.

The present invention will be described in detail through examples below, but the protection scope of the present invention is not limited thereto.

In the following examples, ethylene glycol, ethylene glycol monomethyl ether and ethylene glycol monoethyl ether were all purchased from Shanghai Merrill Chemical Technology Co., Ltd., with a purity of >99%; concentrated sulfuric acid was purchased from Sinopharm Chemical Reagent Co., Ltd., with a purity of 98%; the olefins are all commercially available.

The purity of the product alkyl diether compound was measured by gas chromatography (Agilent GC-7980B).

Example 1

This example is used to illustrate the preparation method of the alkyl diether compounds provided by the present invention.

160 g of ethylene glycol monomethyl ether and 24 ml of concentrated sulfuric acid were added into an autoclave with a volume of 2 L, and after stirring evenly, the autoclave was sealed and replaced with nitrogen three times. Subsequently, 480 g of isobutylene gas with a pressure of 0.2 MPa was introduced, and the autoclave was heated to 80° C. for 2 hours to react. After cooling down to 25°C, the reaction was stopped, and the resulting reaction mixture was poured into a mixture of 0.8L of 5% by weight NaOH solution and 0.5kg of ice cubes, and stirred for 10 minutes until the pH value was stable at 7. The neutralized product is separated, the organic phase is separated, and the organic phase is dried with anhydrous magnesium sulfate, and then the crude product is distilled under normal pressure, and then rectified, and the fraction with a gas phase purity ≥ 98% is collected to obtain the product methoxyethyl tertiary butyl ether. The yield was 72.5%.

Fig. 1 is the proton nuclear magnetic resonance spectrogram of product methoxyethyl tert-butyl ether, and Fig. 2 is the carbon nuclear magnetic resonance spectrogram of product methoxyethyl tert-butyl ether.

Example 2

This example is used to illustrate the preparation method of the alkyl diether compounds provided by the present invention.

160 g of ethylene glycol monoethyl ether and 18 ml of concentrated sulfuric acid were added into an autoclave with a volume of 2 L, and after stirring evenly, the autoclave was sealed and replaced with nitrogen three times. Subsequently, 480 g of isobutylene gas with a pressure of 0.3 MPa was introduced, and the temperature of the autoclave was raised to 70° C. for 3 hours to react. Stop the reaction after cooling down to 40°C, pour the resulting reaction mixture into a mixture of 10% by weight NaOH solution and 0.5kg ice cubes with a concentration of 0.3L, stir for 20 minutes until the pH value is stable at 8, and use a separatory funnel for the above-mentioned mixture. Separate from the product, separate the organic phase, dry the organic phase with anhydrous magnesium sulfate, and then carry out rectification after distilling out the crude product under normal pressure, collect the fraction with a gas phase purity ≥ 98%, and obtain the product ethoxyethyl tert-butyl base ether. The yield was 78.4%.

Fig. 3 is the proton nuclear magnetic resonance spectrogram of product ethoxy ethyl tert-butyl ether, and Fig. 4 is the carbon nuclear magnetic resonance spectrogram of product ethoxy ethyl tert-butyl ether.

Example 3

This example is used to illustrate the preparation method of the alkyl diether compounds provided by the present invention.

Add 160 g of ethylene glycol and 12 ml of concentrated sulfuric acid into an autoclave with a volume of 2 L, seal the autoclave after stirring evenly, and replace with nitrogen three times. Subsequently, 480 g of isobutylene gas with a pressure of 0.4 MPa was introduced, and the autoclave was heated to 75° C. for 2.5 hours to react. Cool down to 35°C to stop the reaction, pour the resulting reaction mixture into a mixture of 0.1L of 20% by weight NaOH solution and 0.5kg of ice cubes, stir for 15 minutes until the pH value is stable at 7.5, and use a separatory funnel for the above-mentioned mixture. Separate the product from the product, separate the organic phase, dry the organic phase with anhydrous magnesium sulfate, then carry out rectification after distilling out the crude product under normal pressure, collect the fraction with a gas phase purity ≥ 98%, and obtain the product ethylene glycol di-tert-butyl ether. The yield was 81.3%.

Fig. 5 is the proton nuclear magnetic resonance spectrogram of product ethylene glycol di-tert-butyl ether, and Fig. 6 is the carbon nuclear magnetic resonance spectrogram of product ethylene glycol di-tert-butyl ether.

Example 4

This example is used to illustrate the preparation method of the alkyl diether compounds provided by the present invention.

160 g of ethylene glycol monoethyl ether and 18 ml of concentrated sulfuric acid were added into an autoclave with a volume of 0.5 L, and after stirring evenly, the autoclave was sealed and replaced with nitrogen three times. Subsequently, 180 g of ethylene gas with a pressure of 0.4 MPa was introduced, and the temperature of the autoclave was raised to 70° C. for 3 hours to react. Stop the reaction after cooling down to 40°C, pour the resulting reaction mixture into a mixture of 10% by weight NaOH solution and 0.5kg ice cubes with a concentration of 0.3L, stir for 20 minutes until the pH value is stable at 8, and use a separatory funnel for the above-mentioned mixture. Separate from the product, separate the organic phase, dry the organic phase with anhydrous magnesium sulfate, then distill the crude product under normal pressure and carry out rectification, collect the fraction with a gas phase purity ≥ 98%, and obtain the product 1,2-diethoxy ethyl ethane. The yield was 74.6%.

Example 5

This example is used to illustrate the preparation method of the alkyl diether compounds provided by the present invention.

160 g of ethylene glycol monoethyl ether and 18 ml of concentrated sulfuric acid were added into an autoclave with a volume of 1 L, and after stirring evenly, the autoclave was sealed and replaced with nitrogen three times. Subsequently, 280 g of propylene gas with a pressure of 0.3 MPa was introduced, and the temperature of the autoclave was raised to 90° C. for 4 hours to react. Stop the reaction after cooling down to 40°C, pour the resulting reaction mixture into a mixture of 10% by weight NaOH solution and 0.5kg ice cubes with a concentration of 0.3L, stir for 20 minutes until the pH value is stable at 8, and use a separatory funnel for the above-mentioned mixture. Separate from the product, separate the organic phase, dry the organic phase with anhydrous magnesium sulfate, and then carry out rectification after the crude product is distilled under normal pressure, and collect the fraction with a gas phase purity ≥ 98% to obtain the product ethoxyethyl isopropyl base ether. The yield was 75.5%.

Example 6

This example is used to illustrate the preparation method of the alkyl diether compounds provided by the present invention.

160 g of ethylene glycol monoethyl ether and 18 ml of concentrated sulfuric acid were added into an autoclave with a volume of 1 L, and after stirring evenly, the autoclave was sealed and replaced with nitrogen three times. Subsequently, 480 g of 1-butene gas at a pressure of 0.3 MPa was introduced, and the temperature of the autoclave was raised to 75° C. to react for 3 hours. Stop the reaction after cooling down to 40°C, pour the resulting reaction mixture into a mixture of 10% by weight NaOH solution and 0.5kg ice cubes with a concentration of 0.3L, stir for 15 minutes until the pH value is stable at 7, and use a separatory funnel for the above-mentioned mixture. Separate from the product, separate the organic phase, dry the organic phase with anhydrous magnesium sulfate, then distill the crude product under normal pressure and carry out rectification, collect the fraction with a gas phase purity ≥ 98%, and obtain the product ethoxyethyl sec-butyl base ether. The yield was 78.1%.

From the results of the above examples, it can be seen that by adopting the preparation method of the alkyl diether compound of the present invention, the yield of the obtained target compound is high and the product purity is high.

Claims (10)

1. a kind of preparation method of the alkyl diether compounds shown in formula (I), it is characterized in that, the method comprises: in the presence of the vitriol oil, with the ethylene glycol of structure as shown in formula (II) Contact reaction between compounds and C ₂ -C ₈ olefins; Wherein, R ₁ and R ₂ are each independently a C ₁ -C ₈ alkyl group, and R ₁ and R ₂ are not methyl at the same time; R' ₁ is hydrogen or a C ₁ -C ₈ alkyl group. 2. The preparation method according to claim 1, wherein, R ₁ and R ₂ are each independently a C ₂ -C ₄ alkyl group, and the C ₂ -C ₈ olefin is a C ₂ -C ₄ olefin, _R'1 is hydrogen or C ₂ -C ₄ alkyl. 3. The preparation method according to claim ₂ , wherein, R and R are each independently ethyl, isopropyl, sec _- butyl or tert-butyl, and the C2 _- C8 _alkene is ethylene, Propylene, 1-butene, 2-butene or isobutene, _R'1 is hydrogen, ethyl, isopropyl, sec-butyl or tert-butyl. 4. The preparation method according to any one of claims 1-3, wherein the conditions of the contact reaction include: the temperature is 50-100° C., and the time is 1.5-4 hours; preferably, the temperature is 60-90° C. °C, more preferably 70-80 °C; the time is preferably 2-3 hours. 5. according to the preparation method described in any one in claim 1-3, wherein, the molar ratio of the consumption of the ethylene glycol compound and the C2 _- C8 _alkene of described structure such as formula (II) is 0.1-0.5:1, preferably 0.15-0.3:1. 6. according to the preparation method described in any one in claim 1-3, wherein, the weight ratio of the ethylene glycol compound shown in formula (II) and the concentrated sulfuric acid consumption of described structure is 3-15: 1, Preferably it is 3-8:1. 7. according to the preparation method described in any one in the claim 1-3, wherein, described C ₂ -C ₈ alkene passes in the reaction system in the form of gas, the pressure of described C ₂ -C ₈ alkene 0.2-0.4MPa. 8. The preparation method according to any one of claims 1-3, wherein the preparation method further comprises: after the contact reaction, cooling the reaction mixture to 20-40°C, and cooling the cooled The mixture is mixed with a neutralizer. 9. preparation method according to claim 8, wherein, described neutralizing agent is selected from at least one in alkali and/or alkaline salt; Preferably, described neutralizing agent is selected from NaOH, Ca(OH) ₂ and at least one of KOH. 10. The preparation method according to claim 8, wherein the conditions for mixing the cooled reaction mixture with the neutralizing agent include: the time is 10-20 minutes, and the temperature is 0°C to 5°C.