Ketone compound ethynylation method
By using ionic liquid to absorb acetylene under normal temperature and pressure to carry out acetylene acetylene reaction to acetylene explosion and ammonia recovery under high pressure, the problems of high energy consumption are solved, efficient and safe production of alkyne alcohols is achieved, and the process flow is simplified. Improves the conversion and selectivity of the product.
Patent Information
- Application Number
- CN202310747965.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-25
- Publication Date
- 2024-12-27
AI Technical Summary
The existing acetyleneization method of ketone compounds has problems such as the risk of acetylene decomposition and explosion under high pressure conditions, high energy consumption for ammonia recovery, complex distillation process resulting from catalysts, and risk of tower kettle clogging.
Using ionic liquid as acetylene soluble agent and catalyst, by reacting ketone compounds with acetylene under normal temperature and pressure, using ionic liquid to absorb acetylene and conducting acetylation reaction in a tubular reactor, reducing the demand for high-pressure equipment and simplifying the separation process And recover ionic liquid.
It realizes efficient acetylation reaction under normal temperature and pressure, reduces energy consumption, avoids explosion risks, simplifies the separation process, improves the conversion and selectivity of the product, and eliminates the need for liquid ammonia and salt catalysts, reducing waste salt generation .
Smart Images
Figure CN119191942A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an energy-saving and green ethynylation method, and in particular to a method for obtaining corresponding acetylenic alcohol compounds through ethynylation of ketone compounds. Background Art
[0002] Alkynol is a kind of organic compound with alkynyl and hydroxyl groups. It can be used as surfactant, wetting agent, defoamer, metal corrosion inhibitor and organic chemical intermediate. It is widely used in medicine, pesticide, cosmetics, synthetic materials and other fields. Common synthesis methods of alkynols include: organometallic reagent method, solid potassium hydroxide catalyzed acetylation method and liquid ammonia-potassium hydroxide catalyzed acetylation method. The general formula of the reaction of acetylene and ketone compounds is:
[0003]
[0004] Wherein R1 and R2 are hydrogen or hydrocarbon groups.
[0005] DSM patent CN1558888A uses a tubular reactor for high pressure reaction, and uses liquid ammonia to dissolve acetylene in an alkaline anion exchange resin system to obtain aldehydes or ketones in a tubular reactor under pressurized conditions. This method needs to be carried out under relatively high pressure.
[0006] CN1675152A uses an ammonia-alkali metal hydroxide aqueous solution system to react aldehyde or ketone with acetylene to obtain alkynol. The reaction uses liquid ammonia as a solvent, so it needs to be carried out under high pressure conditions.
[0007] CN102476978A uses ketone and acetylene as raw materials, uses flake potassium hydroxide as a catalyst, uses ether and water as solvents, and adds a non-ionic surfactant. Water is removed under azeotropic conditions, potassium hydroxide is suspended in the organic phase, and after cooling to below 20°C, ketone and acetylene are introduced under normal pressure for reaction. However, this method is difficult to separate products.
[0008] CN110467519A uses N,N-dimethylformamide as solvent and alcohol salt or amino salt as catalyst to react ketone and acetylene. This method uses salt as catalyst, which is easy to precipitate during the distillation process, making subsequent separation difficult; and solvent recovery requires azeotropic distillation, which consumes a lot of energy.
[0009] CN106117010A discloses a novel process for synthesizing acetylene alcohol from acetylene and ketone compounds. The process mixes acetylene with solvent ammonia and compresses it, then adds quantitative ketones and potassium hydroxide catalyst, completes the acetylation reaction in the reactor, and adds ammonium chloride to terminate the reaction. The reaction solution is passed through a pressurized degassing tower, a normal pressure degassing tower, a scraper evaporator, a ketone removal tower, and a dealkynol removal tower to obtain a crude acetylene alcohol product, and then a membrane separation is performed to obtain an anhydrous acetylene alcohol product. The pressurized degassing tower in the process needs to be carried out under high pressure, which has high requirements for equipment. And acetylene gas has an explosion risk under high pressure, and strict control is required to reduce the risk.
[0010] It can be seen that the prior art methods for ethynylation of ketone compounds have the following deficiencies:
[0011] 1. The acetylene ammonia system involves ammonia recovery and ammonia liquefaction, which has high energy consumption and the risk of ammonia leakage.
[0012] 2. Acetylene decomposes under high pressure, which may cause explosion risk. Avoiding the operation of acetylene under high pressure is an inherent safety feature.
[0013] 3. The use of catalysts (such as sodium hydroxide solution) may lead to the risk of tower blockage in the subsequent distillation process.
[0014] 4. To solve this risk, process water needs to be introduced as a new impurity, making the subsequent distillation process more complicated. Summary of the invention
[0015] In view of the shortcomings of the existing acetylation reaction technology of ketone compounds, the present invention provides an ethynylation method of ketone compounds, wherein an ionic liquid is used as an acetylene dissolving agent. After acetylene is absorbed by the ionic liquid, the absorption liquid and the ketone compound are introduced into a tubular reactor together. In the presence of the ionic liquid, the ketone compound undergoes an ethynylation reaction to obtain a corresponding acetylenic alcohol compound. The method has the advantages of mild reaction, easy control, easy product separation, solvent recovery, no use of liquid ammonia as a solvent, reduced energy consumption, no generation of waste salt, etc.
[0016] According to the present invention, a method for acetylation of ketone compounds is provided, which comprises the following steps:
[0017] S1: introducing acetylene into the ionic liquid to form an ionic liquid that absorbs acetylene;
[0018] S2: adding a ketone compound having a structure represented by the general formula (I) to the ionic liquid having absorbed acetylene obtained in step S1, and reacting to obtain an alkynol compound having a structure represented by the general formula (II);
[0019] Wherein, in step S1, the ionic liquid absorbing acetylene is formed under the following conditions:
[0020] The temperature is 0 to 40°C, preferably 10 to 30°C; the pressure is not higher than 0.15 MPaG and not lower than 0.075 MPaG, preferably 0.075 to 0.12 MPaG;
[0021]
[0022] Wherein R1 is hydrogen, branched or linear C 1-20 Alkyl or C 2-20 Alkenyl, preferably hydrogen, branched or straight-chain C 1-10 Alkyl or C 2-10 Alkenyl, more preferably hydrogen, branched or straight-chain C 1-6 Alkyl or C 2-6 For example, R1 is hydrogen, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, hexyl, vinyl, propenyl, butenyl, pentenyl or hexenyl.
[0023] Preferably, the molar ratio of the ionic liquid to the ketone compound is 1.0 to 2.5:1, preferably 1.2 to 2.2:1.
[0024] Preferably, the reaction conditions of step S2 are: the reaction temperature is 0 to 50° C., preferably 10 to 40° C.; the reaction pressure is not higher than 0.15 MPaG, preferably 0.075 MPaG to 0.12 MPaG.
[0025] Preferably, the reaction pressure in step S2 is greater than or equal to the pressure in step S1.
[0026] Preferably, the ketone compounds include but are not limited to acetone, 6-methyl-5-heptene-2-one, 6-methyl-2-heptanone, geranyl acetone, tetrahydrogeranyl acetone, and plant ketones, and the structural formulas are:
[0027]
[0028] The corresponding acetylenic alcohol compounds obtained are: 2-methyl-3-butyn-2-ol, dehydrolinalool, dihydrodehydrolinalool, dehydronerolidol, tetrahydrodehydronerolidol, dehydroisophytol, and the structural formulas are:
[0029]
[0030] Preferably, the ionic liquid is selected from 1-butyl-3-methylimidazolium acetate ionic liquid [Bmim][OAc], 1-butyl-3-methylimidazolium hexanoate ionic liquid [Bmim][C5COO], 1-butyl-3-methylimidazolium octanoate ionic liquid [Bmim][C7COO], 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid [Bmim][BF4], tetra-n-butyl-n-hexanoic acid phosphonium ionic liquid [P4444 ][C5COO] and tetrabutylphosphonium octanoate ionic liquid [P 4444 ][C7COO].
[0031] In the present invention, the ionic liquid is used as a solvent, and its main function is to promote the dissolution of acetylene gas, ensure that its liquid phase system can dissolve a sufficient amount of acetylene gas under low pressure, and maintain a suitable reaction rate. The ionic liquid is also used as a reaction catalyst to ensure the acetylation reaction rate in the liquid phase.
[0032] Preferably, the purity of acetylene used in the ethynylation reaction is above 99.5%, and acetylene is continuously introduced into the ionic liquid. High-pressure acetylene has an explosion risk. To ensure safety, the system pressure after acetylene is introduced is not higher than 0.15 MPaG, preferably 0.075-0.12 MPaG. The acetylene absorption temperature is 0-40°C, preferably 10-30°C.
[0033] Preferably, step S2 is carried out in a tubular reactor, wherein the flow velocity of the reaction liquid in the tube is 0.1 to 0.5 m / s, preferably 0.2 to 0.4 m / s.
[0034] Preferably, the acetylation method of ketone compounds according to the present invention further comprises the following steps:
[0035] S3: After the acetylation reaction is completed, the reaction liquid is evaporated under reduced pressure to recover acetylene;
[0036] S4: The liquid phase obtained in step S3 is subjected to vacuum distillation to separate the ionic liquid and the acetylene alcohol compound.
[0037] Preferably, the reduced pressure evaporation conditions of step S3 are: reduced pressure evaporation temperature is 20 to 80° C., preferably 40 to 60° C.; and pressure is 0.01 to 0.05 MPaA, preferably 0.02 to 0.04 MPaA.
[0038] Preferably, step S4 is carried out in a distillation tower.
[0039] In some specific embodiments of the present invention, the reaction liquid obtained at the reactor outlet is transferred to a low-pressure tank, and the unreacted acetylene gas in the reaction liquid is removed at the above temperature and pressure, and the acetylene gas is recycled. The remaining liquid is a mixture of the reaction product and the ionic liquid.
[0040] In the present invention, after the reduced pressure evaporation, the liquid phase is subjected to reduced pressure distillation to remove the product and recover the ionic liquid. During the reduced pressure distillation process, the organic matter is evaporated from the system, extracted from the top of the distillation tower and subsequently purified, and the ionic liquid in the bottom of the tower can be recycled after recovery, with a recovery rate of ≥99.0%.
[0041] In the present invention, the organic matter obtained by vacuum distillation, i.e., the product acetylenic alcohol compound, can be further purified and separated by conventional methods, such as rectification, distillation, crystallization, etc.
[0042] The acetylation method of ketone compounds of the present invention has a ketone compound conversion rate of ≥98.0%, an acetylenic alcohol selectivity of ≥98.0%, and an ionic liquid recovery rate of ≥99.0%.
[0043] Compared with the prior art, the present invention has the following beneficial effects:
[0044] 1. The reaction system uses ionic liquid as acetylene solvent, which can be dissolved at room temperature and pressure and has a large solubility. By setting the acetylene in excess, the conversion rate of ketone compounds is high, and acetylene is easy to separate. There is no need to use high-pressure equipment, and the operation is simple and safe.
[0045] 2. The reaction system does not use liquid ammonia as a solvent, which saves energy costs and is environmentally friendly.
[0046] 3. The reaction system uses ionic liquid as a catalyst. There is no problem of catalyst precipitation during the separation process, and there is no need to neutralize the catalyst, which avoids the generation of waste salt, simplifies the process flow, and is environmentally friendly.
[0047] 4. The reaction system does not introduce water, the raw material conversion rate is 98.34-99.68%, the selectivity is 98.13-99.81%, and the product yield is 96.50-99.49%.
[0048] 5. The ionic liquid used in the reaction system can be recovered after distillation separation, and the recovery rate is ≥99.0%.
[0049] The present invention is described in detail below in conjunction with embodiments. DETAILED DESCRIPTION
[0050] Example 1
[0051] Acetylation of phytosterols to generate dehydroisophytol
[0052] 89.2 g of 40 wt% tetra-n-butylphosphonium hydroxide aqueous solution was mixed with 18.6 g of n-octanoic acid, and stirred at 40° C. for 24 h to obtain tetra-n-butylphosphonium n-octanoate ionic liquid. The ionic liquid solution obtained by the neutralization reaction was subjected to rotary evaporation at 50° C. to remove water, and then vacuum dried for 12 h to obtain n-butylphosphonium n-octanoate ionic liquid [P 4444 ][C7COO].
[0053] Add the above-prepared ionic liquid to the autoclave, pass acetylene into the dissolving kettle and maintain the pressure in the kettle at 0.1MPaG, start stirring and keep the reactor temperature at 25°C. The ionic liquid solution absorbing acetylene and plant ketone are passed into a Φ10mm×24m tubular reactor together, the molar ratio of ionic liquid to plant ketone is 1.7:1.0, the reaction temperature is controlled at 20°C, the reaction pressure is 0.1MPaG, the flow rate of the reaction liquid in the reactor is 0.2m / s, and the reaction time is 2h. The reaction outlet liquid is transferred to a pressure reducing tank with a pressure of 0.03MPaA to remove the remaining acetylene gas at 40°C, and the acetylene gas is recycled. The obtained liquid is sent to a vacuum distillation tower for further separation, and the dehydrogenated isophytol product is obtained at the top of the tower, and the ionic liquid is recycled in the tower. The product is analyzed by gas chromatography, and the reaction conversion rate is 99.68%, the selectivity is 99.81%, and the product yield is 99.49% based on plant ketone. The recovery rate of ionic liquid is 99.8%.
[0054] Example 2
[0055] Acetylation of Geranylacetone to Dehydronerolidol
[0056] 95.1 g of 40 wt% tetra-n-butylphosphonium hydroxide aqueous solution was mixed with 16.0 g of n-hexanoic acid, and stirred at 40° C. for 24 h to obtain tetra-n-butylphosphonium hexanoate ionic liquid. The ionic liquid solution obtained by the neutralization reaction was subjected to rotary evaporation at 50° C. to remove water, and then vacuum dried for 12 h to obtain n-butylphosphonium hexanoate ionic liquid [P 4444 ][C5COO].
[0057] Add the above-prepared ionic liquid to the autoclave, pass acetylene into the autoclave and maintain the pressure in the autoclave at 0.075 MPaG, start stirring and keep the reactor temperature at 25°C. Pass the ionic liquid that absorbs acetylene and geranyl acetone into a Φ10mm×24m tubular reactor together, the molar ratio of the ionic liquid to geranyl acetone is 1.7:1.0, the reaction temperature is controlled at 20°C, the reaction pressure is 0.12 MPaG, the flow rate of the reaction liquid in the reactor is 0.2 m / s, and the reaction time is 2h. The reaction outlet liquid is transferred to a pressure reducing tank with a pressure of 0.03 MPaA to remove the remaining acetylene gas at 40°C, and the acetylene gas is recycled. The obtained liquid is sent to a vacuum distillation tower for further separation, and the dehydrogenated nerolidol product is obtained at the top of the tower. The ionic liquid is recycled in the tower bottom. The product is analyzed by gas chromatography, and the reaction conversion rate is 99.81%, the selectivity is 98.34%, and the product yield is 98.15% based on geranyl acetone. The recovery rate of ionic liquid was 99.6%.
[0058] Example 3
[0059] Acetylation of Geranylacetone to Dehydronerolidol
[0060] Preparation of 1-Butyl-3-methylimidazolium n-hexanoate ionic liquid [Bmim][C5COO] by acid-base neutralization method
[0061] 153.5 g of 20 wt% 1-butyl-3-methylimidazolium hydroxide ethanol solution was mixed with 22.8 g of n-hexanoic acid, and the mixture was stirred and reacted at 40°C for 24 hours to obtain 1-butyl-3-methylimidazolium n-hexanoate ionic liquid. The ionic liquid solution obtained by the neutralization reaction was subjected to rotary evaporation at 50°C to remove ethanol, and then vacuum dried for 12 hours to obtain 1-butyl-3-methylimidazolium n-hexanoate ionic liquid [Bmim][C5COO].
[0062] Add the above ionic liquid to the autoclave, pass acetylene into the autoclave and maintain the pressure in the autoclave at 0.12MPaG, start stirring and keep the reactor temperature at 25°C. Pass the ionic liquid that absorbs acetylene and geranyl acetone into a Φ10mm×24m tubular reactor together, the molar ratio of the ionic liquid to geranyl acetone is 1.5:1.0, the reaction temperature is controlled at 20°C, the reaction pressure is 0.12MPaG, the flow rate of the reaction liquid in the reactor is 0.2m / s, and the reaction time is 2h. The reaction outlet liquid is transferred to a pressure reducing tank with a pressure of 0.03MPaA to remove the remaining acetylene gas at 40°C, and the acetylene gas is recycled. The obtained liquid is sent to a vacuum distillation tower for further separation, and the dehydrogenated nerolidol product is obtained at the top of the tower. The ionic liquid is recycled in the tower bottom. The product is analyzed by gas chromatography, and the reaction conversion rate is 99.13%, the selectivity is 98.21%, and the product yield is 97.36% based on geranyl acetone. The recovery rate of ionic liquid was 99.5%.
[0063] Comparative Example 1
[0064] 89.2 g of 40 wt% tetra-n-butylphosphonium hydroxide aqueous solution was mixed with 18.6 g of n-octanoic acid, and stirred at 40° C. for 24 h to obtain tetra-n-butylphosphonium n-octanoate ionic liquid. The ionic liquid solution obtained by the neutralization reaction was subjected to rotary evaporation at 50° C. to remove water, and then vacuum dried for 12 h to obtain n-butylphosphonium n-octanoate ionic liquid [P 4444 ][C7COO].
[0065] Add the above-prepared ionic liquid to the autoclave, pass acetylene into the dissolving kettle and maintain the pressure in the kettle at 0.04MPaG, start stirring and keep the reactor temperature at 25°C. The ionic liquid solution absorbing acetylene and the plant ketone are passed into a Ф10mm×24m tubular reactor together, the molar ratio of the ionic liquid to the plant ketone is 1.7:1.0, the reaction temperature is controlled at 20°C, the reaction pressure is 0.05MPaG, the flow rate of the reaction liquid in the reactor is 0.2m / s, and the reaction time is 2h. The reaction outlet liquid is transferred to a pressure reducing tank with a pressure of 0.03MPaA to remove the remaining acetylene gas at 40°C, and the acetylene gas is recycled. The obtained liquid is sent to a vacuum distillation tower for further separation, and the dehydrogenated isophytol product and the unreacted plant ketone raw material are obtained at the top of the tower. The ionic liquid is recycled in the tower. The product is analyzed by gas chromatography, and the reaction conversion rate is 69.23%, the selectivity is 73.85%, and the product yield is 51.13% based on plant ketone. The recovery rate of ionic liquid was 99.6%.
[0066] Comparing Example 1 with Comparative Example 1, it can be seen that when the acetylation reaction of ketone compounds is carried out according to the method of the present invention, the conversion rate of ketone monomers is higher and the selectivity of the product is higher.
Claims
1. A method for the acetylation of a ketone compound, comprising the following steps: S1: introducing acetylene into the ionic liquid to form an ionic liquid that absorbs acetylene; S2: adding a ketone compound having a structure represented by the general formula (I) to the ionic liquid having absorbed acetylene obtained in step S1, and reacting to obtain an alkynol compound having a structure represented by the general formula (II); in, In step S1, an ionic liquid absorbing acetylene is formed under the following conditions: The temperature is 0 to 40°C, preferably 10 to 30°C; the pressure is not higher than 0.15 MPaG and not lower than 0.075 MPaG, preferably 0.075 to 0.12 MPaG; Wherein R1 is hydrogen, branched or straight chain C 1-20 Alkyl or C 2-20 Alkenyl, preferably hydrogen, branched or straight-chain C 1-10 Alkyl or C 2-10 Alkenyl, more preferably hydrogen, branched or straight-chain C 1-6 Alkyl or C 2-6 Alkenyl.
2. The method for acetylation of ketone compounds according to claim 1, wherein: The molar ratio of the ionic liquid to the ketone compound is 1.0 to 2.5:1, preferably 1.2 to 2.2:
1.
3. The method for acetylation of ketone compounds according to claim 1 or 2, wherein: The reaction conditions of step S2 are: reaction temperature is 0-50°C, preferably 10-40°C; reaction pressure is not higher than 0.15 MPaG and not lower than 0.075 MPaG, preferably 0.075 MPaG-0.12 MPaG.
4. The method for acetylation of a ketone compound according to any one of claims 1 to 3, wherein: The ketone compound is selected from acetone, 6-methyl-5-heptene-2-one, 6-methyl-2-heptanone, geranyl acetone, tetrahydrogeranyl acetone and plant ketone.
5. The method for acetylation of a ketone compound according to any one of claims 1 to 4, wherein: The ionic liquid is selected from 1-butyl-3-methylimidazolium acetate ionic liquid [Bmim][OAc], 1-butyl-3-methylimidazolium hexanoate ionic liquid [Bmim][C5COO], 1-butyl-3-methylimidazolium octanoate ionic liquid [Bmim][C7COO], 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid [Bmim][BF4], tetra-n-butylphosphonium hexanoate ionic liquid [P 4444 ][C5COO] and tetrabutylphosphonium octanoate ionic liquid [P 4444 ][C7COO].
6. The method for acetylation of a ketone compound according to any one of claims 1 to 5, wherein: The purity of acetylene is above 99.5%, and acetylene is continuously introduced into the ionic liquid.
7. The method for acetylation of a ketone compound according to any one of claims 1 to 6, wherein: Step S2 is carried out in a tubular reactor, wherein the flow velocity of the reaction liquid in the tube is 0.1 to 0.5 m / s, preferably 0.2 to 0.4 m / s.
8. The method for acetylation of a ketone compound according to any one of claims 1 to 7, wherein: The acetylation method of ketone compounds also includes the following steps: S3: After the acetylation reaction is completed, the reaction liquid is evaporated under reduced pressure to recover acetylene; S4: The liquid phase obtained in step S3 is subjected to vacuum distillation to separate the ionic liquid and the acetylene alcohol compound.
9. The method for acetylation of a ketone compound according to any one of claims 1 to 8, wherein: The reduced pressure evaporation conditions of step S3 are: reduced pressure evaporation temperature is 20 to 80° C., preferably 40 to 60° C.; pressure is 0.01 to 0.05 MPaA, preferably 0.02 to 0.04 MPaA; Preferably, step S4 is carried out in a distillation tower.
10. The method for acetylation of a ketone compound according to any one of claims 1 to 9, wherein: The conversion rate of the ketone compounds is ≥98.0%, the selectivity of the alkynol compounds is ≥98.0%, and the recovery rate of the ionic liquid is ≥99.0%.