CN114751823A - Preparation method of n-caprylic acid hexyl ester - Google Patents
Preparation method of n-caprylic acid hexyl ester Download PDFInfo
- Publication number
- CN114751823A CN114751823A CN202210577824.XA CN202210577824A CN114751823A CN 114751823 A CN114751823 A CN 114751823A CN 202210577824 A CN202210577824 A CN 202210577824A CN 114751823 A CN114751823 A CN 114751823A
- Authority
- CN
- China
- Prior art keywords
- caprylic acid
- hexyl ester
- hexanol
- acid hexyl
- esterification reaction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
- B01J31/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
- B01J31/0272—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides containing elements other than those covered by B01J31/0201 - B01J31/0255
- B01J31/0275—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides containing elements other than those covered by B01J31/0201 - B01J31/0255 also containing elements or functional groups covered by B01J31/0201 - B01J31/0269
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
The invention relates to the technical field of organic synthesis, and provides a preparation method of n-caprylic acid hexyl ester, which comprises the following steps: and mixing n-caprylic acid, n-hexanol and tetrabutyl titanate, and then carrying out esterification reaction to obtain n-caprylic acid hexyl ester. The invention takes tetrabutyl titanate as a catalyst for reaction, improves the selectivity of the product of the n-caprylic acid hexyl ester, thereby improving the yield of the n-caprylic acid hexyl ester; meanwhile, the catalyst tetrabutyl titanate is almost non-corrosive, so that the corrosivity of the catalyst to equipment in the preparation process is reduced. The experimental result shows that the yield of the n-caprylic acid hexyl ester can reach more than 80 percent by utilizing the preparation method provided by the invention.
Description
Technical Field
The invention belongs to the technical field of organic synthesis, and particularly relates to a preparation method of n-caprylic acid hexyl ester.
Background
The n-caprylic hexyl ester naturally exists in fruits such as apples, strawberries, bananas, grapes and the like, is colorless or yellowish clear liquid in appearance, is extremely insoluble in water, is soluble in organic solvents such as ethanol, diethyl ether, oils and the like, is edible spice allowed by GB/T2760-2014 Chinese food additive standard, and is mainly used for blending edible essence and daily chemical essence.
The traditional synthetic method of n-caprylic acid hexyl ester comprises the following steps: the preparation method is characterized by taking n-caprylic acid and n-hexanol as raw materials and concentrated sulfuric acid and other protonic acids as catalysts. However, the yield of the n-caprylic acid hexyl ester prepared by the preparation method is relatively low and is generally lower than 60 percent; meanwhile, due to the use of protonic acid, the corrosion to equipment is high.
Therefore, it is desired to provide a method for preparing n-caprylic acid hexyl ester with high yield and low corrosion to equipment.
Disclosure of Invention
In view of this, the present invention provides a method for preparing n-caprylic acid hexyl ester. By utilizing the preparation method provided by the invention, the yield of the n-caprylic acid hexyl ester is up to more than 80%, and meanwhile, the catalyst used in the reaction has no corrosiveness, so that the corrosiveness of the preparation process to equipment is reduced.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides a preparation method of n-caprylic acid hexyl ester, which comprises the following steps:
and mixing n-caprylic acid, n-hexanol and tetrabutyl titanate, and then carrying out esterification reaction to obtain n-caprylic acid hexyl ester.
Preferably, the mass of the tetrabutyl titanate accounts for 0.01-0.5% of the total mass of the n-octanoic acid and the n-hexanol.
Preferably, the ratio of the amounts of substances of n-octanoic acid and n-hexanol is 1: (1.5-5).
Preferably, the esterification reaction is carried out in the absence of oxygen.
Preferably, the temperature of the esterification reaction is 110 ℃ to 200 ℃.
Preferably, after the esterification reaction is completed, the product of the esterification reaction is subjected to reduced pressure distillation, neutralization, steam stripping and decolorization in sequence to obtain n-caprylic acid hexyl ester.
Preferably, the temperature of the reduced pressure distillation is 150-200 ℃.
Preferably, the vacuum degree of the reduced pressure distillation is 0.1-0.6 MPa.
Preferably, the neutralizing agent is a lye.
Preferably, the agent for decolorization is activated carbon and/or activated clay.
The invention provides a preparation method of n-caprylic acid hexyl ester, which comprises the following steps: and mixing n-caprylic acid, n-hexanol and tetrabutyl titanate, and then carrying out esterification reaction to obtain n-caprylic acid hexyl ester. The invention takes tetrabutyl titanate as a catalyst for reaction, improves the selectivity of the product of the n-caprylic acid hexyl ester, thereby improving the yield of the n-caprylic acid hexyl ester; meanwhile, the catalyst tetrabutyl titanate is almost non-corrosive, so that the corrosivity of the catalyst on equipment in the preparation process is reduced. The experimental result shows that the yield of the n-caprylic acid hexyl ester can reach more than 80 percent by utilizing the preparation method provided by the invention.
Drawings
FIG. 1 shows the preparation of n-caprylic acid hexyl ester in example 1 of the present invention1H-NMR chart;
FIG. 2 is a graph showing the IR comparison of n-octanoate prepared in accordance with example 1 of the present invention (upper half of FIG. 2) with a standard sample of n-octanoate (lower half of FIG. 2);
FIG. 3 is a GC-MS graph of hexyl n-octanoate prepared in accordance with example 1 of the present invention;
FIG. 4 is a GC graph of hexyl n-octanoate prepared in accordance with example 1 of the present invention.
Detailed Description
The invention provides a preparation method of n-caprylic acid hexyl ester, which comprises the following steps:
and mixing n-caprylic acid, n-hexanol and tetrabutyl titanate, and then carrying out esterification reaction to obtain n-caprylic acid hexyl ester.
The invention preferably mixes and heats the n-caprylic acid and the n-hexanol, and then adds the tetrabutyl titanate to carry out esterification reaction to obtain the n-caprylic hexyl ester.
In the present invention, the ratio of the amounts of the substances of n-octanoic acid and n-hexanol is preferably 1: (1.5-5), more preferably 1: (2-3). The invention limits the use amount of n-hexanol to be more than that of n-octanoic acid, thus ensuring the reaction of n-octanoic acid to be complete; on the other hand, the product can be used as a water-carrying agent to carry out the water generated in the esterification reaction from the reaction system, thereby improving the conversion rate of the raw materials.
In the invention, the heating temperature is preferably 110-130 ℃, and more preferably 120 ℃. In the present invention, the temperature to which the heating is carried out is a temperature at which the esterification reaction starts to proceed. According to the invention, the n-caprylic acid and the n-hexanol are heated to the temperature, and then the catalyst is added, so that the inactivation of the catalyst before the temperature is raised can be avoided, the side reaction can be avoided, and the yield of the n-caprylic acid hexyl ester is improved.
In the present invention, the mass of the tetrabutyl titanate is preferably 0.01 to 0.5%, more preferably 0.03 to 0.1%, of the total mass of the n-octanoic acid and the n-hexanol. In the present invention, the tetrabutyl titanate is preferably added in the form of a solution of tetrabutyl orthotitanate in n-hexanol. The tetrabutyl orthotitanate is used as a catalyst for reaction, so the dosage is small. In order to facilitate the addition and avoid introducing other impurities, the raw material of n-hexanol is taken as a solvent and added into the reaction system in a solution form. In the invention, the mass concentration of the tetrabutyl orthotitanate n-hexanol solution is preferably 5-15%, and more preferably 10%. The dosage of the n-butyl titanate n-hexanol solution is not specially specified, so that the mass of the effective component n-butyl titanate in the added n-butyl titanate n-hexanol solution accounts for 0.01-0.5% of the total mass of the starting materials n-octanoic acid and n-hexanol.
In the present invention, the esterification reaction is preferably carried out under oxygen-free conditions. The oxygen-free conditions are not particularly specified in the invention, and the synthesis can be carried out by adopting the oxygen-free conditions known by the technical personnel in the field. The invention limits the reaction to be carried out under the condition of no oxygen, so as to avoid the adverse effect of oxygen on the reaction.
In the present invention, the temperature of the esterification reaction is 110 to 200 ℃, more preferably 160 to 180 ℃. In the invention, the esterification reaction can slowly occur at the temperature of more than 100 ℃; because the boiling point of the n-hexanol is 156-157 ℃, the esterification reaction temperature is finally kept in the range of 160-180 ℃, so that the full esterification reaction can be realized, the boiling of the n-hexanol can be utilized to take out the water generated by the esterification reaction from the system, and the yield of the n-caprylic acid hexyl ester is improved. The time of the esterification reaction is not specially specified, when no water drops are generated in the oil-water separator, a reaction system is sampled and analyzed for acidity value, when the acidity is less than 0.1%, the heating can be stopped, and the reaction is stopped; when the acidity is more than 0.1%, the reaction time is properly prolonged. In the present invention, the acidity value is preferably a mass ratio of the n-octanoic acid to the total material in the reaction system. The method for detecting the acidity value is not particularly specified in the invention, and a material ratio detection mode well known to those skilled in the art can be adopted, such as gas phase or liquid phase chromatographic analysis.
After the esterification reaction is finished, the invention preferably carries out reduced pressure distillation, neutralization, steam stripping and decoloration on the product of the esterification reaction in sequence to obtain the n-caprylic acid hexyl ester.
In the invention, the temperature of the reduced pressure distillation is preferably 150-200 ℃, and more preferably 160-180 ℃; the vacuum degree of the reduced pressure distillation is preferably 0.1-0.6 MPa, and more preferably 0.2-0.5 MPa. The temperature and the vacuum degree of the reduced pressure distillation are limited in the range, so that the n-hexanol in the reaction system can be sufficiently removed.
In the present invention, the neutralizing agent is preferably a lye. The alkali liquor is not specified in the invention, and the alkali liquor well known to the skilled person can be used. The invention removes n-octanoic acid which does not react in a reaction system by using alkali liquor. In the invention, in order to fully neutralize the unreacted n-caprylic acid in the reaction system, the neutralizing temperature is preferably 140-200 ℃, and more preferably 160-180 ℃; the neutralizing time is preferably 0.5-1.5 h, and more preferably 1 h.
The invention has no special regulation on the stripping mode, and adopts the stripping mode known by the technicians in the field to directly contact the reaction system with the water vapor, so that the impurities which are not removed in the reaction system are diffused into the gas phase according to a certain proportion, thereby achieving the purpose of purifying the product. According to the invention, a stripping mode is adopted to further remove a small amount of hexanol and n-octanoic acid which are not removed in a reaction system.
In the present invention, the decolorizing agent is activated carbon and/or activated clay, and more preferably activated carbon and activated clay. When the activated carbon and the activated clay are simultaneously selected as the decoloring agents, the proportion of the activated carbon to the activated clay is not specially specified, and the full decoloring of a reaction system can be realized. The dosage of the decolorizing agent is not specially specified, and the full decolorizing of the reaction system can be realized by adopting the dosage of the decolorizing agent well known by the technical personnel in the field. In the present invention, activated clay is a polar adsorbent and is commonly used for adsorbing polar impurities; the activated carbon is non-polar adsorption and is commonly used for adsorbing non-polar impurities, so the activated carbon and the activated carbon are matched for use, and the full decolorization of a reaction system is favorably realized.
The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. The described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
1. Synthesis reaction
1.1 feeding: adding 291.4g of n-octanoic acid and 417g of n-hexanol into a 5L 4-port glass reaction kettle; introducing nitrogen into the reaction materials for 1 minute, heating to 120 ℃, adding 4g of catalyst (10 mass percent of n-hexanol solution of tetrabutyl titanate), continuously heating to 180 ℃, keeping the temperature until no water beads are generated in the oil-water separator, sampling and analyzing the acidity value, stopping heating when the acidity is less than 0.1%, and stopping reaction. (the mass ratio of the n-caprylic acid to the n-hexanol is 1:2, and the mass of the tetrabutyl titanate accounts for 0.056 percent of the total weight of the starting materials of the n-caprylic acid and the n-hexanol)
2. Purification of
2.1 negative pressure dealcoholization
Carrying out negative pressure distillation on the crude product after the reaction is finished to remove unreacted n-hexanol, wherein the vacuum degree is controlled to be 0.2-0.5 MPa, and the temperature is controlled to be 160-180 ℃; dealcoholizing, namely removing vacuum when no n-hexanol flows into the oil-water separator, and finishing dealcoholizing.
2.2 neutralization deacidification
And adding 10g of sodium carbonate aqueous solution into the dealcoholized crude product, wherein the mass concentration of the sodium carbonate aqueous solution is 10%, heating to 160-180 ℃, and stirring for 1 hour under the condition of heat preservation.
2.3 stripping of pure Water
Adding 20 ml of pure water into the neutralized and deacidified crude product at intervals, and keeping the temperature between 160 and 180 ℃; and finishing steam stripping when no water drops flow into the oil-water separator.
2.4 adsorption decolorization
5 g of activated carbon and 5 g of activated clay were added to the crude product after the stripping of pure water, and the mixture was stirred for 1 hour.
2.5 filtration
And filtering the crude product subjected to adsorption decoloration by using a filter flask to obtain 382g of a finished product with the yield of about 84%.
Nuclear magnetic testing of hexyl n-octanoate prepared in example 11The H-NMR chart is shown in FIG. 1.
Nuclear magnetic characterization data:1H-NMR(350MHz，CDCl3)δ0.86-0.91(m，6H)，1.26-1.37(m，14H)，1.58-1.65(m，4H)，2.27-2.30(t，2H)，4.04-4.07(t，2H)。
IR contrast plots were obtained by infrared detection of the hexyl n-octanoate prepared in example 1 and a standard sample of hexyl n-octanoate, see FIG. 2. As can be seen from FIG. 2, the IR library search of the prepared sample and the standard has very high matching with the standard spectrum, which indicates that the compound prepared by the invention is n-caprylic acid hexyl ester.
The hexyl n-octanoate prepared in example 1 was subjected to a gas chromatography-mass spectrometry combination test, and the resulting GC-MS graph is shown in FIG. 3. As can be seen from FIG. 3, the molecular fragment ion peak contains 228.4, while the molecular weight of n-caprylic acid hexyl ester is 228.34, which indicates that the compound prepared by the present invention is n-caprylic acid hexyl ester.
The hexyl n-octanoate prepared in example 1 was subjected to gas chromatography and the resulting GC-chart was found to be shown in FIG. 4. As can be seen from FIG. 4, the purity of n-caprylic acid hexyl ester prepared by the present invention is more than 99.0%.
In conclusion, the compound prepared by the invention is characterized by H-NMR, IR and GC-MS, and the compound prepared by the invention is proved to be n-caprylic acid hexyl ester; the purity of the prepared n-caprylic acid hexyl ester is more than 99.0 percent according to GC analysis.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. A preparation method of n-caprylic acid hexyl ester comprises the following steps:
mixing n-caprylic acid, n-hexanol and tetrabutyl titanate for esterification reaction to obtain n-caprylic hexyl ester.
2. The production method according to claim 1, wherein the mass of tetrabutyl titanate is 0.01 to 0.5% of the total mass of n-octanoic acid and n-hexanol.
3. The method according to claim 1, wherein the ratio of the amounts of the substances of n-octanoic acid and n-hexanol is 1: (1.5-5).
4. The method of claim 1, wherein the esterification reaction is carried out in the absence of oxygen.
5. The method according to claim 1, wherein the temperature of the esterification reaction is 110 to 200 ℃.
6. The method according to claim 1, wherein after the esterification reaction is completed, the product of the esterification reaction is subjected to reduced pressure distillation, neutralization, stripping and decolorization in this order to obtain hexyl n-octanoate.
7. The method according to claim 6, wherein the temperature of the reduced pressure distillation is 150 to 200 ℃.
8. The method according to claim 6, wherein the vacuum degree of the reduced pressure distillation is 0.1 to 0.6 MPa.
9. The method of claim 6, wherein the neutralizing agent is a lye.
10. The process according to claim 6, wherein the decolorizing agent is activated carbon and/or activated clay.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210577824.XA CN114751823A (en) | 2022-05-25 | 2022-05-25 | Preparation method of n-caprylic acid hexyl ester |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210577824.XA CN114751823A (en) | 2022-05-25 | 2022-05-25 | Preparation method of n-caprylic acid hexyl ester |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114751823A true CN114751823A (en) | 2022-07-15 |
Family
ID=82334394
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210577824.XA Pending CN114751823A (en) | 2022-05-25 | 2022-05-25 | Preparation method of n-caprylic acid hexyl ester |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114751823A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113527094A (en) * | 2021-08-20 | 2021-10-22 | 孟永财 | Triethylene glycol n-isooctanoic acid diester and preparation method and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1539810A (en) * | 2003-10-28 | 2004-10-27 | 天津大学 | Method for synthesizing ester by using acid water as catalyzer |
| CN113527094A (en) * | 2021-08-20 | 2021-10-22 | 孟永财 | Triethylene glycol n-isooctanoic acid diester and preparation method and application thereof |
| CN113754536A (en) * | 2021-09-08 | 2021-12-07 | 孟永财 | Preparation method of triethylene glycol di-n-caprylate |
-
2022
- 2022-05-25 CN CN202210577824.XA patent/CN114751823A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1539810A (en) * | 2003-10-28 | 2004-10-27 | 天津大学 | Method for synthesizing ester by using acid water as catalyzer |
| CN113527094A (en) * | 2021-08-20 | 2021-10-22 | 孟永财 | Triethylene glycol n-isooctanoic acid diester and preparation method and application thereof |
| CN113754536A (en) * | 2021-09-08 | 2021-12-07 | 孟永财 | Preparation method of triethylene glycol di-n-caprylate |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113527094A (en) * | 2021-08-20 | 2021-10-22 | 孟永财 | Triethylene glycol n-isooctanoic acid diester and preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| HUE031328T2 (en) | Methods and systems for solvent purification | |
| CN114751823A (en) | Preparation method of n-caprylic acid hexyl ester | |
| DE2409731C2 (en) | Process for the esterification of trichlorosilane | |
| CN101289395B (en) | Method for preparing methyl ethyl carbonate | |
| CN102976897A (en) | Method for purifying tetrafluoro propanol | |
| CN109651128A (en) | A kind of continuous production method of milk lactone synthetic perfume | |
| CN105170046B (en) | A kind of DMP Neutralisation treatment methods | |
| CN109134247A (en) | A kind of preparation method and system of pentaerythritol ester | |
| JPH07228590A (en) | Production of sucrose fatty acid ester | |
| CN108383702B (en) | Method for extracting citronellal from litsea cubeba head oil | |
| CN108003096B (en) | Method for preparing ethoxyquinoline through WO3/AC/SO3H concerted catalysis | |
| Kobayashi et al. | Flavor of Black Tea: Part I. Volatile Organic Acids | |
| CN112225653B (en) | Green synthesis method of natural benzaldehyde | |
| RU2686071C1 (en) | Method of purifying a fraction of head ethyl alcohol | |
| UA62017C2 (en) | A method for producing glyoxylic acid esters or hydrates thereof | |
| Bi et al. | Chemical esterification of fusel oil alcohol for the production of flavor and fragrance esters | |
| CN109694324A (en) | A kind of preparation method of methyl benzoate | |
| CN105085209B (en) | A kind of preparation method of high-purity cocker aldehyde | |
| CN115417739B (en) | Synthetic method of natural equivalent terpinene | |
| EP3684747B1 (en) | Method of preparing glycol esters with low color and peroxide content | |
| Cambie et al. | 380. Chemistry of the higher fungi. Part XIV. Polyacetylenic metabolites of Poria sinuosa Fr. | |
| RU2565769C1 (en) | Method of obtaining 1,2-dibutoxybenzene | |
| CN113979836B (en) | Preparation method of 4-isopropenyl-1-methyl-2-cyclohexene-1-ol | |
| NO140344B (en) | PROCEDURE FOR PREPARATION OF NEW N2-DANSYL-L-ARGIN INDIVATIVES | |
| RU2510629C1 (en) | Method of obtaining pentaerythrite trichlorohydrin |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |