Method for preparing various ethers through reaction of calcium methoxide and halogenated hydrocarbon

Abstract

The invention discloses a method for preparing various ethers by reacting calcium methoxide with halogenated hydrocarbon, and belongs to the field of preparation of ethers. According to the method, calcium methoxide reacts with benzyl, allyl and long-chain alkyl halogenated hydrocarbon and polyhalogenated hydrocarbon such as chloroform and carbon tetrachloride in different alcohol solvents, and methyl ether, ethyl ether, propyl ether and butyl ether are synthesized with high selectivity through in-situ exchange reaction of the calcium methoxide and the alcohol solvents, and the method belongs to the field of chemical synthesis. The method is characterized by comprising the following steps: adding calcium methoxide, an alcohol solvent, an auxiliary agent and halogenated hydrocarbon into a high-temperature and high-pressure reaction kettle, and stirring and reacting at 60-200 DEG C for 1-12 hours; and after the reaction is finished, separating the product to obtain various asymmetric ethers and orthoformate. The method has great significance in large-scale high-value utilization of calcium methoxide which is a downstream by-product of calcium carbide, and has a good industrial application prospect.

Description

Technical Field

[0001] The invention belongs to the field of chemical synthesis, and specifically relates to a method for preparing various asymmetric ethers and orthoformates by reacting calcium methoxide with halogenated hydrocarbons. Background Art

[0002] There are many methods for the synthesis of ethers, the most commonly used of which is the Williamson synthesis. The Williamson method generates the corresponding ether and metal halide by the reaction of alkoxide and alkyl halide. Its essence is the nucleophilic substitution of alkoxide ion and alkyl halide (S N 2) Reaction. The most commonly used alcoholate is sodium alcoholate, which is mainly prepared by metal method or alkali method, and the production cost is high, which greatly limits the industrial application of Williamson ether synthesis method.

[0003] Calcium carbide is an important part of the coal chemical industry. Acetylene is prepared by hydrolysis of calcium carbide, and various organic products such as PVA, PVC, BDO, etc. are synthesized by acetylene. However, the acetylene produced by this method usually contains H2S, PH3 and water, and the post-processing is complicated. Patent US 3009964 A proposes a new process for synthesizing high-purity acetylene and calcium methoxide in one step by reacting calcium carbide with methanol.

[0004] CaC2+2CH3OH→HC≡CH↑+Ca(CH3O)2

[0005] This method avoids the generation of a large amount of wastewater and carbide slag, and methanol does not react with impurities such as calcium sulfide, calcium arsenide, and calcium phosphide in carbide, thereby avoiding the generation of H2S, AsH3, and PH3. The byproduct calcium methanol produced by the alcoholysis of carbide is stable in nature, and there is no high-value conversion and utilization technology. Therefore, the development of large-scale high-value conversion technology for calcium methanol is of great significance to the promotion of green processes for preparing acetylene from carbide and the development of carbide chemical industry.

[0006] The reaction conditions of the present invention are mild, the raw materials are widely available and cheap, the production cost is low, the yield of the target product is high, the equipment requirements are low, the steps are simple, and the method has important industrial application value. Summary of the invention

[0007] The present invention aims to develop a new method for synthesizing asymmetric ethers and / or orthoformates, and to produce high-value ethers using calcium methoxide and halogenated hydrocarbons as raw materials. This is a new method for large-scale utilization of calcium methoxide, and also a new process for efficient synthesis of asymmetric ethers and orthoformates. The reaction equation is as follows:

[0008] Ca(OCH3)2+2R1X→2R1OCH3+CaX2

[0009] Ca(OCH3)2+2R1X+2R2OH→2R1OR2+2CH3OH+CaX2

[0010] The technical scheme of the present invention is: adding a certain mass of calcium methoxide, solvent, halogenated hydrocarbon and auxiliary agent into a high-temperature and high-pressure reaction kettle, sealing it, and then performing a thermal reaction; after the reaction is completed, asymmetric ether and / or orthoformate can be obtained by separation.

[0011] The halogenated hydrocarbons include, but are not limited to, monohalogenated hydrocarbons R1X (R1 may be a C1-20 alkyl group, a C3-20 monoolefin group, a benzyl group, such as benzyl chloride (bromide), chloro (bromo) propylene, bromo (chloro) propane, chloro (bromo) butane), corresponding trihalogenated hydrocarbons or / and tetrahalogenated hydrocarbons (such as corresponding chloroform, carbon tetrachloride) and other halogenated hydrocarbons, one or more thereof. X is halogen, preferably chlorine or / and bromine.

[0012] The solvent includes but is not limited to alcohols R2OH (R2 can be a C1-20 alcohol as required, such as methanol, ethanol, propanol, butanol, etc.).

[0013] The auxiliary agents include but are not limited to potassium fluoride, potassium carbonate, potassium sulfate, sodium fluoride, sodium carbonate, and sodium sulfate.

[0014] In order to achieve complete reaction of halogenated hydrocarbons, a slight excess of calcium methoxide is maintained during the reaction, and the molar ratio of calcium methoxide to halogenated hydrocarbons is 0.5-2. Usually, an excess of calcium methoxide needs to be added; the molar ratio of solvent to halogen atom is greater than or equal to 1:1; the molar ratio of auxiliary agent to halogenated hydrocarbon is (0-2):1 (for example, when highly active halogenated hydrocarbons (benzyl, allyl, bromohalogenated hydrocarbons) are used, no auxiliary agent is required, and when low active halogenated hydrocarbons (chloroform, carbon tetrachloride, chlorocarbons) are used, auxiliary agents need to be added). After the reaction is completed, the reactor is cooled to room temperature.

[0015] Further, monohalogenated hydrocarbon R1X and alcohol R2OH solvents are used to obtain the corresponding R1OR2 ethers; when the halogenated hydrocarbon uses the corresponding trihalogenated hydrocarbon or / and tetrahalogenated hydrocarbon and alcohol R2OH, the corresponding orthoformate is obtained (the halogen of the halogenated hydrocarbon is replaced by the alkoxy group of R2OH).

[0016] The temperature of the thermal reaction is 60-200°C, and the reaction is stirred for 1-12 hours.

[0017] The present invention can convert calcium methoxide into high-value alkyl ether and orthoformate bulk chemicals on a large scale, and realize the large-scale utilization of calcium methoxide byproducts. Compared with the Williamson ether synthesis method, the present invention replaces sodium alcoholate or potassium alcoholate with inexpensive calcium methoxide; and different alkyl ethers can be produced with the change of alcohol solvent, enriching the types of ether products. The present invention realizes the efficient resource utilization of calcium methoxide, solves the worries of the green process of preparing acetylene by calcium carbide alcoholysis, and has good economic benefits and industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Gas phase and mass spectrometry of the solution after the reaction for preparing benzyl methyl ether

[0019] Figure 2 Gas phase and mass spectrometry of the solution after the reaction for the preparation of benzyl ethyl ether

[0020] Figure 3 Gas phase and mass spectrometry of the solution after the reaction for the preparation of benzyl propyl ether

[0021] Figure 4 Gas chromatography-mass spectrometry of the solution after the reaction for the preparation of allyl methyl ether

[0022] Figure 5 Gas chromatography-mass spectrometry of the solution after the reaction for the preparation of propyl methyl ether

[0023] Figure 6 Gas chromatography-mass spectrometry of the solution after the reaction of preparing trimethyl orthoformate from chloroform

[0024] Figure 7 Gas chromatography-mass spectrometry of the solution after the reaction of preparing trimethyl orthoformate from carbon tetrachloride DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with specific examples, which are only intended to illustrate the technical solution of the present invention and cannot be regarded as limiting the content of the claims of the present invention. In the following specific examples, the raw materials used are all commercially available industrial products, and the equipment used are all conventional equipment.

[0026] Embodiment 1:

[0027] Calcium methoxide reacts with 1-chlorobutane to prepare methyl butyl ether. Weigh 1.45g of calcium methoxide, 1.86g of 1-chlorobutane, 5.20g of methanol, and 1.16g of potassium fluoride and place them in a 50mL high-temperature and high-pressure reactor. After sealing the reactor, react at 150°C for 1h, and the yield of methyl butyl ether can reach 68%.

[0028] Embodiment 2:

[0029] Calcium methoxide reacts with 1-bromopropane to prepare methyl propyl ether. Weigh 1.45g of calcium methoxide, 2.45g of 1-bromopropane, 5.20g of methanol, and 1.15g of potassium fluoride and place them in a 50mL high-temperature and high-pressure reactor. After sealing the reactor, react at 100°C for 10h, and the yield of methyl propyl ether can reach 82%.

[0030] Embodiment 3:

[0031] Allyl methyl ether was prepared by reacting calcium methoxide with allyl chloride. 1.45 g of calcium methoxide, 1.54 g of allyl chloride, and 5.20 g of methanol were weighed and placed in a 50 mL high temperature and high pressure reactor. After the reactor was sealed, the reaction was carried out at 150°C for 8 hours, and the yield of allyl methyl ether could reach 84%.

[0032] Embodiment 4:

[0033] Calcium methoxide reacts with benzyl chloride to prepare benzyl methyl ether. Weigh 1.50g of calcium methoxide, 2.55g of benzyl chloride, and 5.30g of methanol and put them into a 50mL high-temperature and high-pressure reactor. After sealing the reactor, react at 150°C for 2h, and the yield of benzyl methyl ether can reach 95%.

[0034] Embodiment 5:

[0035] Calcium methoxide reacts with benzyl chloride to prepare benzyl methyl ether. Weigh 1.50g of calcium methoxide, 2.55g of benzyl chloride, and 5.30g of methanol and put them into a 50mL high-temperature and high-pressure reactor. After sealing the reactor, react at 120°C for 8h, and the yield of benzyl methyl ether can reach 96%.

[0036] Embodiment 6:

[0037] Calcium methoxide reacts with benzyl chloride to prepare benzyl ethyl ether. 1.50 g of calcium methoxide, 2.55 g of benzyl chloride, and 5.30 g of ethanol were weighed and placed in a 50 mL high temperature and high pressure reactor. After the reactor was sealed, the reaction was carried out at 150°C for 8 hours, and the yield of benzyl ethyl ether was 90%.

[0038] Embodiment 7:

[0039] Calcium methoxide reacts with benzyl chloride to prepare benzyl propyl ether. 1.50 g of calcium methoxide, 2.54 g of benzyl chloride, and 5.30 g of propanol were weighed and placed in a 50 mL high temperature and high pressure reactor. After the reactor was sealed, the reaction was carried out at 150°C for 8 hours, and the yield of benzyl propyl ether was 87%.

[0040] Embodiment 8:

[0041] Allyl ethyl ether was prepared by reacting calcium methoxide with allyl chloride. 1.50 g of calcium methoxide, 1.55 g of allyl chloride, and 5.40 g of ethanol were weighed and placed in a 50 mL high temperature and high pressure reactor. After the reactor was sealed, the reaction was carried out at 150°C for 8 hours, and the yield of allyl ethyl ether was 66%.

[0042] Embodiment 9:

[0043] Calcium methoxide reacts with ethyl bromide to prepare methyl ethyl ether. Weigh 1.45g of calcium methoxide, 2.17g of ethyl bromide, and 5.20g of methanol and put them into a 50mL high-temperature and high-pressure reactor. After sealing the reactor, react at 150°C for 2h, and the yield of methyl ethyl ether can reach 41%.

[0044] Embodiment 10:

[0045] Calcium methoxide reacts with chloroform to prepare trimethyl orthoformate. Weigh 1.54g of calcium methoxide, 0.76g of chloroform, and 7.20g of methanol and put them into a 50mL high-temperature and high-pressure reactor. After sealing the reactor, react at 150°C for 12h, and the yield of trimethyl orthoformate can reach 82%.

[0046] Embodiment 11:

[0047] Calcium methoxide reacts with carbon tetrachloride to prepare trimethyl orthoformate. Weigh 1.54g of calcium methoxide, 0.77g of carbon tetrachloride, and 7.20g of methanol and put them into a 50mL high-temperature and high-pressure reactor. After sealing the reactor, react at 200°C for 8h, and the yield of trimethyl orthoformate can reach 70%.

Claims

1. A method for preparing various ethers by reacting calcium methoxide with halogenated hydrocarbons, characterized in that: A certain amount of calcium methoxide, solvent, halogenated hydrocarbon and auxiliary agent are added into a high temperature and high pressure reactor, which is sealed and then subjected to thermal reaction. After the reaction is completed, asymmetric ether and / or orthoformate can be obtained by separation.

2. A method for preparing various ethers by reacting calcium methoxide with halogenated hydrocarbons according to claim 1, characterized in that: The halogenated hydrocarbons include, but are not limited to, monohalogenated hydrocarbons R1X (R1 may be a C1-20 alkyl group, a C3-20 monoolefin group, a benzyl group, such as benzyl chloride (bromide), chloro (bromo) propylene, bromo (chloro) propane, chloro (bromo) butane), corresponding trihalogenated hydrocarbons or / and tetrahalogenated hydrocarbons (such as corresponding chloroform, carbon tetrachloride) and other halogenated hydrocarbons, one or more thereof. X is halogen, preferably chlorine or / and bromine.

3. A method for preparing various ethers by reacting calcium methoxide with halogenated hydrocarbons according to claim 1, characterized in that: The solvent includes but is not limited to alcohols R2OH (R2 can be a C1-20 alcohol as required, such as methanol, ethanol, propanol, butanol, etc.).

4. A method for preparing various ethers by reacting calcium methoxide with halogenated hydrocarbons according to claim 1, characterized in that: The auxiliary agents include but are not limited to potassium fluoride, potassium carbonate, potassium sulfate, sodium fluoride, sodium carbonate, and sodium sulfate.

5. A method for preparing various ethers by reacting calcium methoxide with halogenated hydrocarbons according to claim 1, characterized in that: The molar ratio of calcium methoxide to halogenated hydrocarbon is 0.5-2; the molar ratio of solvent to halogen atom is greater than or equal to 1:1; the molar ratio of auxiliary agent to halogenated hydrocarbon is (0-2):

1. After the reaction is completed, the reactor is cooled to room temperature.

6. A method for preparing various ethers by reacting calcium methoxide with halogenated hydrocarbons according to claim 5, characterized in that: For example, when using highly active halogenated hydrocarbons (benzyl, allyl, bromohalogenated hydrocarbons), no auxiliary agent is required, but when using low-active halogenated hydrocarbons (chloroform, carbon tetrachloride, chlorinated hydrocarbons), auxiliary agents need to be added.

7. A method for preparing various ethers by reacting calcium methoxide with halogenated hydrocarbons according to claim 1, characterized in that: The corresponding R1OR2 ethers are obtained by using monohalogenated hydrocarbon R1X and alcohol R2OH as solvents; when the halogenated hydrocarbon uses the corresponding trihalogenated hydrocarbon or / and tetrahalogenated hydrocarbon and alcohol R2OH, the corresponding orthoformate is obtained (the halogen of the halogenated hydrocarbon is replaced by the alkoxy group of R2OH).

8. A method for preparing various ethers by reacting calcium methoxide with halogenated hydrocarbons according to claim 1, characterized in that: The temperature of the thermal reaction is 60-200°C, and the reaction is stirred for 1-12 hours.

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