CN106748696B - Preparation method of methyl ionone and intermediate thereof - Google Patents
Preparation method of methyl ionone and intermediate thereof Download PDFInfo
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- CN106748696B CN106748696B CN201611229304.0A CN201611229304A CN106748696B CN 106748696 B CN106748696 B CN 106748696B CN 201611229304 A CN201611229304 A CN 201611229304A CN 106748696 B CN106748696 B CN 106748696B
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- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/61—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups
- C07C45/67—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton
- C07C45/68—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms
- C07C45/72—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms by reaction of compounds containing >C = O groups with the same or other compounds containing >C = O groups
- C07C45/74—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms by reaction of compounds containing >C = O groups with the same or other compounds containing >C = O groups combined with dehydration
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- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/61—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups
- C07C45/67—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton
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Abstract
The invention discloses a preparation method of methyl ionone and an intermediate thereof. The existing preparation of methyl ionone usually needs to waste a large amount of alkali, and on the other hand, a large amount of three wastes are also caused. According to the invention, citral and butanone are used as raw materials, PEG is used as a solvent, and metal hydroxide is used as a condensing agent to carry out Aldol condensation reaction to synthesize pseudo-methyl ionone; the obtained pseudomethylionone is subjected to cyclization reaction under acid catalysis, and the methylionone is synthesized. PEG-M (OH) used in the inventionxThe catalytic condensation system not only improves the synthesis yield of the pseudo-methyl ionone, but also maintains the proportion of the pseudo-iso-methyl ionone at 68-79%; the phosphoric acid-normal hexane catalytic cyclization system adopted by the invention also greatly improves the cyclization yield; the condensation catalyst system adopted by the invention can be recycled for a plurality of times, thereby not only reducing the cost, but also lightening the environmental pollution.
Description
Technical Field
The invention belongs to the field of perfume chemistry and fine chemicals, and particularly relates to a preparation method of methyl ionone and an intermediate thereof.
Background
Methyl ionone is a precious synthetic perfume, has six isomers, cis-isomer, trans-isomer and optical isomer, and is present in a synthetic product as a mixture, wherein α -iso-methyl ionone (α -IMI) isomer with the most typical aroma characteristic usually accounts for more than 60% of the main components.
Methyl ionone is generally prepared by the condensation and cyclization of Citral (Citral) with butanone (MEK) in a manner similar to β -ionone, but much more complex than β -ionone due to the CH in the 1-position of butanone3And CH in position 32Can be used as nucleophilic site to attack aldehyde carbonyl group of citral, so that the condensation reaction can produce two isomeric forms of pseudon-methyl ionone (PNMI) and pseudoiso-methyl ionone (PIMI)As with the cyclization of pseudoionone to form α -ionone, β -ionone and γ -ionone, pseudon-methyl ionone and pseudoisomethyl ionone undergo cyclization reactions to form β 0-n-methyl ionone (β 1-NMI), β -n-methyl ionone (β -NMI), γ -n-methyl ionone (γ -NMI), β 2-isomethyl ionone (α -IMI), β -isomethyl ionone (β -IMI) and γ -isomethyl ionone (γ -IMI) as described above, α -isomethyl ionone (α -IMI) among these isomers is the most unique and developmentally valuable, so the focus of the methyl ionone synthesis process is on how to increase the yield of pseudoisomethyl ionone in the condensation step and how to increase the content of isomethyl ionone in the synthesis step of the pseudoisomethyl ionone α -cyclization reaction as follows:
chinese patent CN02134494.9 reports a method for synthesizing pseudoisomethylionone by catalytic synthesis of pseudoisomethylionone in methanol-KOH or other similar systems. After the reaction is finished, butanone and the solvent are recovered, and then the rest materials are neutralized. Although higher yields are mentioned in the literature, no indication is given as to the ratio of pseudoisomethylionone to pseudonormethylionone; and the process is complicated, a large amount of solvent needs to be recovered, a large amount of alkali catalyst needs to be treated, and more three wastes are generated.
US7141698 also reports a continuous synthesis of pseudomethylionone and methylionone, but it uses a large amount of base catalyst and also requires the use of acetic acid for neutralization, on the one hand, a large amount of base is wasted and on the other hand, a large amount of three wastes are also caused.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a method for preparing qualified methyl ionone and an intermediate thereof, which is suitable for industrial production, can recycle a catalytic system, and is environment-friendly.
Therefore, the invention adopts the following technical scheme: a preparation method of a methyl ionone intermediate takes citral and butanone as raw materials, PEG as a solvent and metal hydroxide as a condensing agent to carry out Aldol condensation reaction to synthesize pseudo methyl ionone.
The other technical scheme of the invention is as follows: a preparation method of methyl ionone comprises the step of carrying out cyclization reaction on pseudo methyl ionone under acid catalysis to synthesize the methyl ionone.
Further, the preparation method comprises the following specific steps: 1) taking citral and butanone as raw materials, PEG as a solvent, and metal hydroxide as a condensing agent, and carrying out Aldol condensation reaction at 0-60 deg.C (preferably 10-20 deg.C) for 0.5-4h (preferably 1-2 h); after the reaction is finished, extracting by adopting an organic solvent which is not compatible with PEG, standing for layering, recovering an alkali-containing PEG solution for reuse, and obtaining an extraction layer which is pseudo-methyl ionone reaction liquid;
2) the pseudomethylionone reaction solution obtained in the step 1) is subjected to cyclization reaction for 1-4h (preferably 1.5-2h) under acid catalysis at 40-80 ℃ (preferably 60-70 ℃), and after the reaction is finished, the methylionone is obtained by water washing, desolventizing and rectification.
The mechanism for preparing α -iso-methyl ionone by reacting butanone and citral is a typical Aldol condensation reaction under the catalysis of alkali, and the difficulty lies in the CH of butanone 13And CH in position 32Can be used as a nucleophilic site to attack aldehyde carbonyl of citral, and butanone has the structure shown as the following formula:
the product obtained by Aldol condensation on the No. 1 position of butanone is pseudo-n-methyl ionone, and the target product pseudo-iso-methyl ionone is obtained on the No. 3 position. However, in general, since the steric hindrance of the 1-position is small, and the H atom on the 1-position is more acidic, and is more likely to react with alkali to form carbanion than the 3-position, the selectivity of Aldol reaction on the 1-position of butanone is much higher than that on the 3-position, for example, in tetrahydrofuran or acetonitrile solvent, the selectivity of n-methyl ionone generated by reaction on the 1-position of butanone is as high as 90% or more.
The invention adopts PEG as the solvent directly, which remodels the microenvironment of butanone in the reaction solvent, so that the activity of the 3 rd site is enhanced because: (1) the PEG is used as a solvent to eliminate the polar interference of other small molecular solvents, (2) an ether chain of the PEG can wrap metal ions in a solution, so that the alkalinity of a metal hydroxide is enhanced, and the formation of carbanions at the 3 th position is facilitated, (3) a terminal hydroxyl group of the PEG can form a hydrogen bond with a ketone group of butanone, so that the steric hindrance of the reaction between the PEG and the 1 st position of citral is increased, and (4) the other beneficial effect of the PEG is realized that the PEG has larger polarity and is not mutually soluble with n-hexane, and the reaction can be completed by separating a product in a n-hexane extraction mode, and a reaction system can be used repeatedly.
The extraction layer (pseudomethylionone reaction liquid) in the step 1) can be directly used for cyclization reaction for preparing methylionone; the method can also be used for intermediate storage, and comprises the following specific steps: and washing the extraction layer with water, washing with saturated salt water, desolventizing and removing weight to obtain the pseudomethylionone with the purity of 99 percent.
Further, the molecular weight of the PEG is 200-600.
Further, the PEG is one or more of PEG200, PEG400 and PEG600, preferably PEG 400.
Further, the dosage of the PEG solvent is 5-15 times of the mass of the citral.
Further, the metal hydroxide is LiOH, NaOH, KOH, CsOH, Ba (OH)2Preferably KOH or CsOH; the feeding molar ratio of the metal hydroxide to the citral is 0.1-2: 1, preferably 0.5 to 1: 1, most preferably 0.8 to 1: 1.
further, the feeding molar ratio of the citral to the butanone is 1:2-20, preferably 1:2-10, and most preferably 1: 4-6.
Further, in the condensation reaction, citral is added in a dropwise manner, and the dropwise addition time is not more than half of the reaction time; in the cyclization reaction, the pseudo-methyl ionone reaction solution is added in a dropwise manner, and the dropwise adding time is not more than half of the reaction time.
Furthermore, the organic solvent insoluble in PEG is n-hexane, the amount of the n-hexane is 5-25 times, preferably 15-25 times of the mass of the citral, and the extraction can be carried out for multiple times.
Further, in the cyclization reaction, the acid is sulfuric acid, phosphoric acid, hydrochloric acid or nitric acid, preferably phosphoric acid, and the using amount of the acid is 0.1-0.5 times of the molar amount of the citral.
By adopting the technical scheme, compared with the prior art, the invention has the beneficial effects that:
(1) PEG-M (OH) used in the inventionxThe catalytic condensation system not only improves the synthesis yield of the pseudo-methyl ionone, which is 91-95%, but also maintains the proportion of the pseudo-iso-methyl ionone at 68-79%.
(2) The phosphoric acid-normal hexane catalytic cyclization system adopted by the invention also greatly improves the cyclization yield to 92-95%, wherein α -iso-methyl ionone is maintained at 60-80%.
(3) The condensation catalyst system adopted by the invention can be recycled for a plurality of times, thereby not only reducing the cost, but also lightening the environmental pollution.
Detailed Description
In order that the invention may be better understood, the following further description is provided by way of example. However, these examples are merely illustrative of the present invention and do not limit the scope of the present invention.
Example 1
Adding PEG-600200 g and potassium hydroxide 11g into a three-necked bottle with a stirring device, a thermometer and a dropping funnel, after the dissolution is finished, adding butanone 100g, dropwise adding a mixed solution of 50g of citral and 20g of butanone into a reaction system under stirring, keeping the temperature for 1 hour after the dropwise addition is finished, keeping the temperature for reaction for 1 hour after the dropwise addition is finished, separating liquid after the reaction is finished, continuously extracting the obtained PEG layer twice with n-hexane, combining the n-hexane layer, washing with water, washing with saturated salt water, distilling under reduced pressure after the solvent is removed by rotary evaporation, collecting the fraction at the temperature of 140Pa/115 and 118 ℃, obtaining a pseudomethylionone product with the purity of 99%, wherein the yield is 94%, and the pseudomethylionone proportion is 75%.
Example 2
Adding PEG-200200 g and potassium hydroxide 11g into a three-necked bottle with a stirring device, a thermometer and a dropping funnel, after the dissolution is finished, adding butanone 100g, dropwise adding a mixed solution of 50g of citral and 20g of butanone into a reaction system under stirring, keeping the temperature for 1 hour after the dropwise addition is finished, keeping the temperature for reaction for 1 hour after the dropwise addition is finished, separating liquid after the reaction is finished, continuously extracting the obtained PEG layer twice with n-hexane, combining the n-hexane layer, washing with water, washing with saturated salt water, distilling under reduced pressure after the solvent is removed by rotary evaporation, collecting the fraction at the temperature of 140Pa/115 and 118 ℃, obtaining a pseudomethylionone product with the purity of 99%, wherein the yield is 92%, and the pseudomethylionone proportion is 73%.
Example 3
Adding PEG-400200 g and potassium hydroxide 11g into a three-necked bottle with a stirring device, a thermometer and a dropping funnel, after the dissolution is finished, adding butanone 100g, dropwise adding a mixed solution of 50g of citral and 20g of butanone into a reaction system under stirring, keeping the temperature for 1 hour after the dropwise addition is finished, heating to 20 ℃, continuing to perform heat preservation reaction for 1 hour, separating liquid after the reaction is finished, continuously extracting the obtained PEG layer twice with n-hexane, combining the n-hexane layer, washing with water, washing with saturated salt water, performing rotary evaporation to remove a solvent, performing reduced pressure distillation, collecting fractions at the temperature of 140Pa/115 and 118 ℃, and obtaining a pseudomethylionone product with the purity of 99%, wherein the yield is 93%, and the ratio of the pseudomethylionone is 76%.
Example 4
Adding PEG-600200 g and cesium hydroxide 29g into a three-necked bottle with a stirring device, a thermometer and a dropping funnel, after the dissolution is finished, adding butanone 100g, dropwise adding a mixed solution of citral 50g and butanone 20g into a reaction system under stirring, keeping the dropwise adding time for 1 hour, keeping the dropwise adding reaction temperature at 10 ℃, after the dropwise adding is finished, heating to 20 ℃, continuing to perform heat preservation reaction for 1 hour, separating liquid after the reaction is finished, continuously extracting the obtained PEG layer twice with n-hexane, combining the n-hexane layer, washing with water, washing with saturated salt water, performing rotary evaporation to remove a solvent, performing reduced pressure distillation, collecting a fraction at the temperature of 140Pa/115 and 118 ℃, and obtaining a pseudomethylionone product with the purity of 99%, wherein the yield is 93%, and the pseudomethylionone proportion is 78%.
Examples 5 to 9
The PEG layer of example 1 was taken and the procedure of example 1 was repeated for 5 cycles, and the results are shown in the following table.
| Serial number | Isomer purity | Yield of | Pseudoisomethylionone |
| Example 5 | 99％ | 94％ | 75％ |
| Example 6 | 99％ | 93％ | 76％ |
| Example 7 | 99％ | 93％ | 75％ |
| Example 8 | 99％ | 92％ | 75％ |
| Example 9 | 99％ | 92％ | 74％ |
Example 10
Adding 28g of 85% phosphoric acid aqueous solution and 21g of n-hexane into a three-necked bottle with a stirring device, a thermometer and a dropping funnel, dropwise adding 50g of pseudoisomethylionone into a reaction system under stirring, dropwise adding for 1 hour, keeping the reaction temperature at 60 ℃, continuously reacting for 1 hour after dropwise adding, adding 250mL of n-hexane and 150mL of water after the reaction is finished, separating, continuously extracting the obtained water layer twice with the n-hexane, combining the n-hexane layer, washing with saturated sodium bicarbonate aqueous solution, washing with saturated salt water, evaporating to remove the solvent, carrying out reduced pressure rectification, collecting fractions at 110Pa/95-98 ℃, obtaining a methylionone product with the purity of 99%, wherein the yield is 96%, and the proportion of α -isomethylionone is 72%.
Example 11
Adding 40g of 60% phosphoric acid aqueous solution and 21g of n-hexane into a three-necked bottle with a stirring device, a thermometer and a dropping funnel, dropwise adding 50g of pseudoisomethylionone into a reaction system under stirring, dropwise adding for 1 hour, keeping the reaction temperature at 60 ℃, continuing to react for 1 hour after the dropwise adding is finished, adding 250mL of n-hexane and 150mL of water after the reaction is finished, separating, continuously extracting the obtained water layer twice with the n-hexane, combining the n-hexane layer, washing with saturated sodium bicarbonate aqueous solution, washing with saturated salt water, evaporating to remove the solvent, carrying out reduced pressure rectification, collecting fractions at 110Pa/95-98 ℃, obtaining a methylionone product with the purity of 99%, wherein the yield is 95%, and the proportion of α -isomethylionone is 68%.
Example 12
Adding PEG-400200 g and potassium hydroxide 11g into a three-necked bottle with a stirring device, a thermometer and a dropping funnel, after the dissolution is finished, adding butanone 100g, dropwise adding a mixed solution of 50g of citral and 20g of butanone into a reaction system under stirring, wherein the dropwise adding time is 1 hour, the dropwise adding reaction temperature is 10 ℃, after the dropwise adding is finished, heating to 20 ℃, continuing to perform heat preservation reaction for 1 hour, separating liquid after the reaction is finished, continuously extracting the obtained PEG layer twice with n-hexane, combining the n-hexane layer, dropwise adding a n-hexane solution containing pseudomethylionone into the three-necked bottle with the stirring device and the thermometer, adding 40g of a phosphoric acid aqueous solution with the concentration of 85% into the three-necked bottle in advance, wherein the dropwise adding time is 1 hour, the reaction temperature is 60 ℃, continuing to react for 1 hour after the dropwise adding is finished, adding 250mL and 150mL of water after the reaction is finished, separating liquid, continuously extracting the obtained water layer twice with the n-hexane, combining the layers, washing with a saturated sodium bicarbonate aqueous solution, washing with a saturated salt solution, performing rotary evaporation to remove a solvent, rectifying, and then collecting a methyl fraction with the purity of 3588% of the vanillin product, wherein the yield is 84-71 Pa.
Claims (8)
1. A preparation method of a methyl ionone intermediate is characterized in that citral and butanone are used as raw materials, PEG is used as a solvent, and metal hydroxide is used as a condensing agent to carry out Aldol condensation reaction to synthesize pseudo methyl ionone;
the PEG is one or more of PEG200, PEG400 and PEG 600; the dosage of the PEG solvent is 5-15 times of the mass of the citral.
2. A preparation method of methyl ionone is characterized in that citral and butanone are used as raw materials, PEG is used as a solvent, and metal hydroxide is used as a condensing agent to carry out Aldol condensation reaction to synthesize pseudo methyl ionone; the PEG is one or more of PEG200, PEG400 and PEG 600; the dosage of the PEG solvent is 5-15 times of the mass of the citral;
the obtained pseudomethylionone is subjected to cyclization reaction under acid catalysis, and the methylionone is synthesized.
3. The process for the preparation of methylionone according to claim 2, characterized in that it comprises the following specific steps:
1) taking citral and butanone as raw materials, PEG as a solvent, and metal hydroxide as a condensing agent, and carrying out Aldol condensation reaction at the temperature of 0-60 ℃ for 0.5-4 h; after the reaction is finished, extracting by adopting an organic solvent which is not compatible with PEG, standing for layering, recovering an alkali-containing PEG solution for reuse, and obtaining an extraction layer which is pseudo-methyl ionone reaction liquid;
2) cyclizing reaction liquid of the pseudomethylionone obtained in the step 1) at 40-80 ℃ for 1-4h under acid catalysis, and washing, desolventizing and rectifying after the reaction is finished to obtain the methylionone.
4. The method according to claim 1, 2 or 3, wherein the metal hydroxide is LiOH, NaOH, KOH, CsOH, Ba (OH)2In a feed molar ratio of metal hydroxide to citral of from 0.1 to 2: 1.
5. the method according to claim 1, 2 or 3, wherein the charging molar ratio of citral to butanone is 1: 2-20.
6. The process according to claim 1, 2 or 3, wherein in the condensation reaction, citral is added dropwise for a period of time not more than half the reaction time; in the cyclization reaction, the pseudo-methyl ionone reaction solution is added in a dropwise manner, and the dropwise adding time is not more than half of the reaction time.
7. The method according to claim 3, wherein the PEG-insoluble organic solvent is n-hexane used in an amount of 5 to 25 times the mass of citral.
8. The process according to claim 2 or 3, wherein the acid used in the cyclization is sulfuric acid, phosphoric acid, hydrochloric acid or nitric acid in an amount of 0.1 to 0.5 times the molar amount of citral.
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| CN108017525B (en) * | 2017-11-30 | 2020-12-01 | 山东新和成药业有限公司 | Synthesis method of alpha-iso-methyl ionone |
| CN108383701A (en) * | 2018-03-05 | 2018-08-10 | 常州大学 | A kind of synthesis technology of lilial intermediate |
| CN109665977B (en) * | 2018-12-21 | 2021-06-15 | 广州百花香料股份有限公司 | Efficient production method of ionone-alpha sodium hydroxysulfonate adduct |
| CN111848378A (en) * | 2020-08-04 | 2020-10-30 | 李金国 | Preparation method of perfume intermediate beta-ionone for cosmetics |
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| CN1394841A (en) * | 2002-08-02 | 2003-02-05 | 广州百花香料股份有限公司 | Method for synthesizing pseudoisomethyl ionone |
| CN1508113A (en) * | 2002-12-19 | 2004-06-30 | 上海应用技术学院 | Industrial method for preparing beta-ionone |
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| CN1394841A (en) * | 2002-08-02 | 2003-02-05 | 广州百花香料股份有限公司 | Method for synthesizing pseudoisomethyl ionone |
| CN1508113A (en) * | 2002-12-19 | 2004-06-30 | 上海应用技术学院 | Industrial method for preparing beta-ionone |
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