CN114853604B - Preparation method of five-carbon aldehyde - Google Patents
Preparation method of five-carbon aldehyde Download PDFInfo
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- CN114853604B CN114853604B CN202210357875.1A CN202210357875A CN114853604B CN 114853604 B CN114853604 B CN 114853604B CN 202210357875 A CN202210357875 A CN 202210357875A CN 114853604 B CN114853604 B CN 114853604B
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/28—Preparation of carboxylic acid esters by modifying the hydroxylic moiety of the ester, such modification not being an introduction of an ester group
- C07C67/293—Preparation of carboxylic acid esters by modifying the hydroxylic moiety of the ester, such modification not being an introduction of an ester group by isomerisation; by change of size of the carbon skeleton
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/08—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
Abstract
The invention provides a preparation method of VA intermediate pentacarbon aldehyde. The method comprises the following steps: (1) Esterifying hydroxy aldehyde in the presence of an acylating agent to form 2-acyloxy aldehyde; (2) Condensing 2-acyloxy acetaldehyde and propionaldehyde under alkaline condition to generate 4-acyloxy-2-methyl-2-butenal (pentacarbon aldehyde). The method takes the hydroxy acetaldehyde as the initial raw material, and the product is obtained in high yield by controlling the content of specific impurities in the hydroxy acetaldehyde.
Description
Technical Field
The invention belongs to the field of chemical intermediate synthesis, and particularly relates to a preparation method of VA intermediate pentacarbon aldehyde.
Background
4-acetoxy-2-methyl-2-butenal (hereinafter referred to as "pentacarbon aldehyde") is an important intermediate for the synthesis of vitamin a. Because of the importance of pentacarbon aldehyde in the vitamin a synthesis industry, the synthesis process of pentacarbon aldehyde has long been a research hotspot.
Patent US5424478 discloses a synthetic route for the preparation of pentacarbon aldehydes starting from isoprene. The method can produce a large amount of wastewater in the production process, and has serious pollution. The synthetic route is as follows:
patent CN103467287a discloses a synthetic route for preparing five-carbon aldehydes from ethylene oxide and acrolein as starting materials. The use of expensive organophosphine reagent and palladium metal catalyst in this route results in low yields of five-carbon aldehydes from intermediate 16 of only 51%. The synthesis process is as follows:
the above methods have certain defects in industrial production, low economical efficiency and complex operation, so that a new process for synthesizing pentacarbon aldehyde is necessary to be developed.
Disclosure of Invention
The invention aims to provide a novel route for synthesizing vitamin A intermediates, which has the advantages of few steps, high yield, simple operation, stable and easily-separated intermediates and good economy.
In order to achieve the above object, the present invention has the following technical scheme:
a preparation method of a vitamin A intermediate pentacarbon aldehyde comprises the following steps:
(1) Forming 2-acyloxyacetaldehyde from hydroxyaldehyde in the presence of an acylating agent;
(2) Condensing 2-acyloxy acetaldehyde with propionaldehyde under alkaline condition to generate 4-acyloxy-2-methyl-2-butenal (pentacarbon aldehyde) with a structural formula shown as formula (II);
in some embodiments, the synthetic route is represented by the formula:
in the invention, the impurity in the raw material hydroxyaldehyde is controlled
(acetal 1) content of 10 to 100ppm, preferably 20 to 40ppm;
in the research process, the content of a key impurity acetal 1 in the raw material hydroxy acetaldehyde has great influence on an acylation reaction auxiliary agent, a possible source of the acetal 1 is self-condensation of the raw material hydroxy acetaldehyde, the content of the acetal 1 is lower than 10ppm, the catalytic action of the auxiliary agent on the reaction is not sufficiently initiated, the reaction speed and the product selectivity are reduced, the content of the acetal 1 is higher than 100ppm, the reaction auxiliary agent is deactivated, and the acylation reaction efficiency is reduced;
in the present invention, the acylating agent in step (1) may be an acid anhydride such as acetic anhydride, propionic anhydride and palmitic anhydride, or an acid chloride such as acetyl chloride, propionyl chloride and palmitoyl chloride; acetic anhydride and acetyl chloride are preferred. The particular type of acylating agent used will depend on the desired VA analogue, and if VA palmitate is desired, then the acylating agent may be selected from palmitic anhydride and palmitoyl chloride.
The molar ratio of acylating agent to hydroxy acetaldehyde is (1-3): 1, preferably (1.1-1.5): 1.
In the invention, in the step (1), an auxiliary agent is required to be added, wherein the auxiliary agent is one or more selected from aluminum trichloride, ferric trichloride, magnesium dichloride, ferric sulfate, aluminum sulfate, magnesium sulfate and ferric acetate, and the mass ratio of the auxiliary agent to the hydroxy acetaldehyde is (0.005-0.1): 1, preferably (0.02-0.05): 1.
in the present invention, step (1) is performed in a solvent selected from one or more of tetrahydrofuran, methanol, ethanol, acetonitrile, n-hexane, toluene, dichloroethane and dimethylformamide, preferably acetonitrile; the ratio of the solvent to the hydroxyacetaldehyde is (0.5-8) L:1kg, preferably (2-6) L:1kg.
In the present invention, the reaction temperature in step (1) is 0 to 100 ℃, preferably 20 to 50 ℃; the reaction time is 1 to 6 hours, preferably 2 to 3 hours.
In the present invention, the molar ratio of propionaldehyde to 2-acyloxyacetaldehyde in step (2) is (1-4): 1, preferably (2-3): 1.
in the invention, the alkali used in the step (2) is selected from one or more of pyridine, sodium hydroxide, potassium hydroxide and triethylamine, preferably sodium hydroxide, and the molar ratio of the alkali to the propionaldehyde is (1-3): 1, preferably (1.5-2): 1.
in the present invention, step (2) is performed in a solvent selected from one or more of water, methanol, ethanol, acetonitrile and toluene, preferably methanol; the dosage ratio of the solvent to the propionaldehyde is (2-10) L:1kg, preferably (3-5) L:1kg.
In the invention, in the step (2), the propionaldehyde, the alkali and the solvent are subjected to a pre-reaction at the temperature of 10-100 ℃, preferably 30-50 ℃ for 1-6 hours, preferably 2-3 hours; then 2-acyloxyacetaldehyde is dripped into the pre-reacted propionaldehyde solution for 1 to 5 hours, preferably 2 to 3 hours; after the 2-acyloxyacetaldehyde is added dropwise, heat preservation is needed, the dropwise addition temperature and the heat preservation temperature are 10-100 ℃, preferably 30-50 ℃, and the heat preservation time is 2-10h, preferably 5-7h.
The invention has the positive effects that:
(1) The reaction steps are few, the total yield is high (the total yield of two steps is more than 85 percent, which is far higher than about 60 percent of the yield in the three-step or four-step route reported in the prior art), the catalyst is cheap and easy to obtain, and the route economy is high;
(2) The corresponding acylating reagent can be selected according to the product requirement, if VA palmitate is required to be prepared, then palmitoyl chloride or anhydride can be selected as the acylating reagent in the step (1), and the regulation and control of the product type are very convenient.
Detailed Description
The following further describes the technical scheme of the present invention, but is not limited thereto, and all modifications and equivalents of the technical scheme of the present invention are included in the scope of the present invention without departing from the scope of the technical scheme of the present invention.
Gas chromatography analysis: chromatographic model: agilent WAX 1701.42249; carrier gas: high-purity nitrogen; sample injection mode: an autosampler; nitrogen flow rate: 66.0ml/min; vaporization chamber temperature: 285 deg.c; split sample injection, split ratio: 1:50; sample injection amount: 0.2 μl; column flow rate 1.8ml/min; column temperature: first-order programming, wherein the initial temperature is 150 ℃, the temperature is kept for 2 minutes, then the temperature is raised to 285 ℃ at the speed of 15 ℃/min, and the temperature is kept for 15 minutes; the detector temperature was 300 ℃; and (5) quantifying by an external standard method.
NMR analysis: nuclear magnetic resonance data [ ] 1 H 400MHz, 13 C100 MHz) was measured by Varian 400NMR spectrometer with CDCl as the dissolving agent 3 。
Some of the reagent specifications and sources in the examples and comparative examples
| Reagent name | Reagent specification | Manufacturing factories |
| Hydroxy acetaldehyde, propanal, acetic anhydride, palmitic anhydride | AR | "Bailingwei |
| Methanol, ethanol, acetonitrile, toluene | AR | Xiyong reagent |
| Ferric trichloride, aluminum trichloride, pyridine, sodium hydroxide and ferric sulfate | AR | Ara Ding Shiji |
Example 1
(1) Preparation of 2-acetoxyacetaldehyde:
120.0g of hydroxyaldehyde (purity: 99.1%, acetal 1 content: 13 ppm), 240.0g of acetonitrile, 2.4g of ferric trichloride and 224.47g of acetic anhydride were charged into a 1L reaction vessel, and the reaction was carried out three times with nitrogen substitution, and the temperature was maintained at 20℃for 3 hours. The reaction liquid is detected by gas chromatography, the conversion rate of the hydroxy acetaldehyde is 99.8 percent, and the selectivity of the 2-acetoxyl acetaldehyde is 97.2 percent.
After the reaction is finished, the 2-acetoxyl acetaldehyde is obtained by rectifying and separating the reaction liquid, the purity is 99.0 percent, and the yield is 98.8 percent.
(2) Preparation of five-carbon aldehyde:
116.08g of propionaldehyde, 237.12g of pyridine and 306.09g of methanol are added into a 2L reaction kettle, stirring is started, the mixture is heated to 30 ℃, stirring is carried out for 2 hours, then 102.03g of 2-acetoxy acetaldehyde is dropwise added at 30 ℃ through a peristaltic pump for 3 hours, and the mixture is kept at 30 ℃ for 5 hours after the dropwise addition. The reaction liquid is detected by gas chromatography, the conversion rate of 2-acetoxyl aldehyde is 99.9%, and the selectivity of five-carbon aldehyde substituted by acetoxyl group is 95.4%.
After the reaction is finished, the reaction liquid is rectified and separated to obtain the pentacarbon aldehyde with the purity of 99.3 percent and the yield of 95.8 percent.
Example 2
(1) Preparation of 2-palmitoyloxy acetaldehyde:
120.0g of hydroxy acetaldehyde (purity: 99.3%, acetal 1 content: 96 ppm), 720.24g of acetonitrile, 6.0g of aluminum trichloride and 1496.58g of palmitic acid anhydride were successively added to a 5L reaction vessel, and the reaction was carried out three times with nitrogen substitution, maintaining the temperature at 50℃and reacting for 3 hours. The reaction liquid is detected by gas chromatography, the conversion rate of the hydroxy acetaldehyde is 99.8 percent, and the selectivity of the 2-palmitoyloxy acetaldehyde is 96.3 percent.
After the reaction, the reaction liquid is rectified and separated to obtain the 2-palmitoyloxy acetaldehyde with the purity of 99.1 percent and the yield of 97.9 percent.
(2) Preparation of five-carbon aldehyde:
174.12g of propionaldehyde, 239.94g of sodium hydroxide and 510.15 ethanol are added into a 2L reaction kettle, stirring is started, the mixture is heated to 50 ℃, stirring is carried out for 3 hours, then 298.25g of 2-palmitoyloxy acetaldehyde is dropwise added at 50 ℃ through a peristaltic pump for 2 hours, and the mixture is kept at 50 ℃ for 7 hours after the dropwise addition is finished. The reaction liquid is detected by gas chromatography, the conversion rate of 2-palmitoyloxy acetaldehyde is 99.9%, and the selectivity of palmitoyloxy substituted five-carbon aldehyde is 95.8%.
After the reaction, the reaction solution is rectified and separated to obtain the pentacarbon aldehyde with the purity of 99.2 percent and the yield of 96.0 percent.
Example 3
(1) Preparation of 2-acetoxyacetaldehyde:
120.0g of hydroxy acetaldehyde (purity 99.2%, acetal 1 content 20 ppm), 60.02g of tetrahydrofuran, 0.6g of ferric trichloride and 204.06g of acetic anhydride were sequentially added into a 2L reaction kettle, and the reaction was carried out for three times with nitrogen substitution, and the temperature was maintained at 10℃for 1.5 hours. The reaction liquid is detected by gas chromatography, the conversion rate of the hydroxy acetaldehyde is 99.6 percent, and the selectivity of the 2-acetoxyl acetaldehyde is 97.5 percent.
After the reaction is finished, the 2-acetoxyl acetaldehyde is obtained by rectifying and separating the reaction liquid, the purity is 99.0 percent, and the yield is 98.8 percent.
(2) Preparation of five-carbon aldehyde:
58.04g of propionaldehyde, 86.94g of pyridine and 204.06g of acetonitrile are added into a 1L reaction kettle, stirring is started, the reaction is maintained at 20 ℃, stirring is carried out for 5 hours, then 102.03g of 2-acetoxyl acetaldehyde is dropwise added at 30 ℃ through a peristaltic pump for 1 hour, and the temperature is raised to 80 ℃ and kept for 2 hours after the dropwise addition is finished. The reaction liquid is detected by gas chromatography, the conversion rate of 2-acetoxyl aldehyde is 99.9%, and the selectivity of five-carbon aldehyde substituted by acetoxyl group is 95.7%.
After the reaction, the reaction liquid is rectified and separated to obtain the pentacarbon aldehyde with the purity of 99.2 percent and the yield of 95.7 percent.
Example 4
(1) Preparation of 2-acetoxyacetaldehyde:
120.0g of hydroxy acetaldehyde (purity: 99.4%, acetal 1 content: 40 ppm), 960.32g of toluene, 12g of ferric sulfate and 612.18g of acetic anhydride were successively added to a 3L reaction vessel, and the reaction was carried out three times with nitrogen substitution, maintaining the temperature at 80℃and reacting for 2 hours. The reaction liquid is detected by gas chromatography, the conversion rate of the hydroxy acetaldehyde is 99.9 percent, and the selectivity of the 2-acetoxyl acetaldehyde is 95.4 percent.
After the reaction, the reaction liquid is rectified and separated to obtain the 2-acetoxyl acetaldehyde with the purity of 99.0 percent and the yield of 97.9 percent.
(2) Preparation of five-carbon aldehyde:
232.16g of propionaldehyde, 479.88g of sodium hydroxide and 1020.3g of acetonitrile are added into a 3L reaction kettle, stirring is started, the reaction is maintained at 70 ℃, stirring is carried out for 6 hours, then 102.03g of 2-acetoxy acetaldehyde is dropwise added at 30 ℃ through a peristaltic pump for 5 hours, and the temperature is reduced to 10 ℃ after the dropwise addition is finished, and the temperature is kept for 10 hours. The reaction liquid is detected by gas chromatography, the conversion rate of 2-acetoxyl aldehyde is 99.9%, and the selectivity of five-carbon aldehyde substituted by acetoxyl group is 95.0%.
After the reaction is finished, the reaction liquid is rectified and separated to obtain the pentacarbon aldehyde with the purity of 99.3 percent and the yield of 95.1 percent.
Comparative example 1
A procedure similar to that of example 1 was used, but in step (1) the acetal 1 content was 150ppm.
(1) Preparation of 2-acetoxyacetaldehyde:
120.0g of hydroxy acetaldehyde (purity: 99.3%, acetal 1 content: 150 ppm), 240.0g of acetonitrile, 2.4g of ferric trichloride and 224.47g of acetic anhydride were successively added to a 1L reaction vessel, and the reaction was carried out three times with nitrogen substitution, maintaining the temperature at 20℃and reacting for 3 hours. The reaction liquid is detected by gas chromatography, the conversion rate of the hydroxy acetaldehyde is 55.8 percent, and the selectivity of the 2-acetoxyl acetaldehyde is 72.1 percent.
From the experimental results, it can be seen that the aldol 1 content is too high, and the aldol conversion and the 2-acetoxyacetaldehyde selectivity are reduced under the same conditions.
Comparative example 2
A procedure similar to that of example 1 was used, but in step (1), the acetal 1 content was 5ppm.
(1) Preparation of 2-acetoxyacetaldehyde:
120.0g of hydroxy acetaldehyde (purity: 99.1%, acetal 1 content: 5 ppm), 240.0g of acetonitrile, 2.4g of ferric trichloride and 224.47g of acetic anhydride were successively added to a 1L reaction vessel, and the reaction was carried out three times with nitrogen substitution, maintaining the temperature at 20℃and reacting for 3 hours. The reaction liquid is detected by gas chromatography, the conversion rate of the hydroxy acetaldehyde is 15.8 percent, and the selectivity of the 2-acetoxyl acetaldehyde is 82.8 percent.
From the experimental results, it can be seen that the acetal 1 content in the hydroxyaldehyde is too low, and the hydroxyaldehyde conversion and the 2-acetoxyacetaldehyde selectivity are reduced under the same conditions.
Claims (22)
1. A preparation method of VA intermediate pentacarbon aldehyde comprises the following steps:
(1) Reacting hydroxy acetaldehyde in the presence of an acylating agent to form 2-acyloxy acetaldehyde;
(2) Condensing 2-acyloxyacetaldehyde with propionaldehyde under alkaline conditions to generate 4-acyloxy-2-methyl-2-butenal;
wherein, impurities in the raw material hydroxy acetaldehyde are controlled
The content is 10-100ppm.
2. The production process according to claim 1, wherein impurities in the raw material hydroxyaldehyde are controlled
The content is 20-40ppm.
3. The process according to claim 1, wherein the acylating agent in step (1) is an acid anhydride or an acid chloride.
4. The method according to claim 3, wherein the acid anhydride is one or more of acetic anhydride, propionic anhydride and palmitic anhydride, and the acid chloride is one or more of acetyl chloride, propionyl chloride and palmitoyl chloride.
5. A process according to claim 3, wherein the acylating agent in step (1) is acetic anhydride or acetyl chloride.
6. The process according to any one of claims 1 to 5, wherein in step (1), the molar ratio of acylating agent to hydroxyaldehyde is (1 to 3): 1.
7. the process according to claim 6, wherein the molar ratio of the acylating agent to the hydroxyaldehyde in step (1) is 1.1 to 1.5.
8. The method according to any one of claims 1 to 5, wherein an auxiliary agent is added in step (1), and the auxiliary agent is one or more selected from the group consisting of aluminum trichloride, iron trichloride, magnesium dichloride, iron sulfate, aluminum sulfate, magnesium sulfate and iron acetate.
9. The preparation method according to claim 8, wherein the mass ratio of the auxiliary agent to the hydroxyaldehyde is (0.005-0.1): 1.
10. the preparation method according to claim 9, wherein the mass ratio of the auxiliary agent to the hydroxyaldehyde is (0.02-0.05): 1.
11. the process according to any one of claims 1 to 5, wherein step (1) is carried out in a solvent selected from one or more of tetrahydrofuran, methanol, ethanol, acetonitrile, n-hexane, toluene, dichloroethane and dimethylformamide.
12. The process according to claim 11, wherein the ratio of solvent to hydroxyacetaldehyde is (0.5 to 8) L:1kg.
13. The process according to any one of claims 1 to 5, wherein the reaction temperature in step (1) is 0 to 100 ℃; the reaction time is 1-6h.
14. The process according to claim 13, wherein the reaction temperature in step (1) is 20 to 50 ℃.
15. The process according to claim 1, wherein the molar ratio of propanal to 2-acyloxyacetaldehyde in step (2) is (1-4): 1.
16. the process according to claim 15, wherein the molar ratio of propanal to 2-acyloxyacetaldehyde in step (2) is (2-3): 1.
17. the process according to claim 1, wherein the base used in step (2) is one or more selected from the group consisting of pyridine, sodium hydroxide, potassium hydroxide and triethylamine.
18. The process according to claim 17, wherein the molar ratio of base to propanal is (1-3): 1.
19. the method according to claim 1, wherein the step (2) is carried out in a solvent selected from one or more of water, methanol, ethanol, acetonitrile and toluene.
20. The process according to claim 19, wherein the ratio of solvent to propionaldehyde is (2-10) L:1kg.
21. The process according to any one of claims 1, 15 to 20, wherein in step (2) the propanal, the base and the solvent are pre-reacted at a temperature of 10 to 100 ℃ for a time of 1 to 6 hours; the 2-acyloxyacetaldehyde was then slowly added to the pre-reacted propionaldehyde solution.
22. The process according to claim 21, wherein the 2-acyloxyacetaldehyde is added in step (2) at a temperature of 10 to 100 ℃ for a period of 2 to 10 hours.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3965157A (en) * | 1973-12-17 | 1976-06-22 | Lilly Industries, Ltd. | Preparation of α-acetoxy aldehydes and ketones |
| CN1238750A (en) * | 1996-12-23 | 1999-12-15 | 巴斯福股份公司 | Method for preparing carbonyl compounds |
| CN1690038A (en) * | 2004-04-19 | 2005-11-02 | 大赛璐化学工业株式会社 | Process for producing 2-benzoyloxyacetaldehyde derivative |
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- 2022-04-06 CN CN202210357875.1A patent/CN114853604B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3965157A (en) * | 1973-12-17 | 1976-06-22 | Lilly Industries, Ltd. | Preparation of α-acetoxy aldehydes and ketones |
| CN1238750A (en) * | 1996-12-23 | 1999-12-15 | 巴斯福股份公司 | Method for preparing carbonyl compounds |
| CN1690038A (en) * | 2004-04-19 | 2005-11-02 | 大赛璐化学工业株式会社 | Process for producing 2-benzoyloxyacetaldehyde derivative |
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