CN101381297B - Method for separating caprylic acid from mixture of caprylic acid and capric acid - Google Patents
Method for separating caprylic acid from mixture of caprylic acid and capric acid Download PDFInfo
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- CN101381297B CN101381297B CN2008101215096A CN200810121509A CN101381297B CN 101381297 B CN101381297 B CN 101381297B CN 2008101215096 A CN2008101215096 A CN 2008101215096A CN 200810121509 A CN200810121509 A CN 200810121509A CN 101381297 B CN101381297 B CN 101381297B
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- sad
- separation method
- capric acid
- substituted pyridines
- water layer
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Abstract
The invention discloses a method for separating octanoic acid from a mixture of octanoic acid and decanoic acid. The separating method is as follows: in a resolution solvent, substitute pyridine fully reacts with the mixture of the octanoic acid and the decanoic acid at reflux temperature, and a compound crystal is separated out after cooling; after being recrystallized, the compound crystal crude product obtained after filtration is hydrolyzed by diluted hydrochloric acid the concentration of which is 2 percent to 10 percent, and is separated to obtain an aqueous layer A and an organic layer A which is washed and dried to obtain the monomer octanoic acid. Compared with the prior art, the method has the advantage of higher resolution efficiency. Due to the high selectivity of molecular recognition, the yield of the monomer octanoic acid can be between 80 and 95 percent and the purity can be between 95 percent and 99 percent only by crystallizing once. Besides, the method has simple operation, good repeatability and low implementation cost, and is advantageous to industrial expansion.
Description
(1) technical field
The present invention relates to a kind of sad method of from hot capric acid mixture, separating.
(2) background technology
As a kind of important industrial raw material, the production of lipid acid and separating technology have longer history.The technology of separation of fatty acids is confined to fairly simple separation mostly always for many years: be about to saturated fatty acid and separate with unsaturated fatty acids, the solid acid and the liquid acid of separating the back gained remain a kind of mixture, the range of application that this has just limited lipid acid has largely reduced its using value widely.If can be with suitable method, further with above-mentioned separated product list from becoming highly purified fatty acid monomer, then can improve the use value of lipid acid greatly, and the prospect of exploitation is very good.
Sad and the capric acid of monomer acids is very important industrial raw material in the manufacturing processed of sanitas, sterilant, spices, dyestuff, softening agent, lubricating oil.At present separate sad the mixing acid and the main basis of capric acid various lipid acid under certain pressure have this characteristic of different boiling points and separate from the hot last of the ten Heavenly stems.Because the boiling point of hot capric acid is all more than 200 ℃, thereby it is higher to separate required cost.
Molecular recognition is one, and it all has extremely important meaning in numerous chemical fields at present very early by the phenomenon that people were familiar with, and wherein just comprises separation science.By the molecular recognition effect, host molecule is optionally discerned guest molecule and is assembled into supramolecular system, and final preferential crystallization comes out owing to can form accumulation closely, thereby realizes the separation of guest molecule.Because the generation of compound crystal only relates to hydrogen bond, Van der Waals force with dissociating, so treating processes less energy-consumption, environmental friendliness.
How the molecular recognition technology being applied to single sour separation in the hot capric acid mixture, is the problem of a very worth research.
(3) summary of the invention
The technical problem to be solved in the present invention is to provide a kind of molecular recognition principle of utilizing simply, efficiently to separate sad method from hot capric acid mixture.
Research thinking of the present invention is: because the length difference of carbochain between lipid acid, and may be because the existence of side chain thereby exist different recognition capability between distinctive main body guest molecule.Develop separation method efficiently by this molecular recognition phenomenon.
For solving the technology of the present invention problem, the present invention adopts following technical scheme: a kind ofly separate sad method from hot capric acid mixture: in resolution solvent, fully react down at 50-80 ℃ suc as formula substituted pyridines shown in (I) and hot capric acid mixture, after 0-30 ℃ of cooling, separate out compound crystal, filtration obtains compound crystal crude product and filtrate, use the hydrochloric acid hydrolysis of concentration 2%-10% behind the gained compound crystal crude product elder generation recrystallization, obtain layering solution, separate obtaining water layer A and organic layer A, organic layer A is sad through washing, be drying to obtain monomer; It is one of following that described resolution solvent is selected from: methyl alcohol, ethanol, acetone, ethyl acetate; Described recrystallization solvent is one of following: methyl alcohol, ethanol, acetone, ethyl acetate.
In the formula (I), R
1Represent OH or NH
2, R
2Represent Cl, Br or H.
Further, separate the water layer A that obtains and obtain substituted pyridines (I) through reclaiming, concrete recovery method is as follows: water layer is adjusted to the pH value with alkali lye〉7, use dichloromethane extraction then, separate the organic layer that obtains and concentrate, substituted pyridines (I) is reclaimed in cooling after the crystallization.
Further, in the substantial sepn process, for fully reclaiming substituted pyridines, the filtrate that can obtain with by filtering separation molecular crystal crude product the time is earlier with the dilute hydrochloric acid hydrolysis of concentration 2%-10%, obtain layering solution, separate to obtain water layer B and organic layer B, water layer A and water layer B are merged to reclaim obtain substituted pyridines (I).
Substituted pyridines of the present invention and hot capric acid mixture following reaction times of condition of 50-80 ℃ of temperature generally at 1-2 hour, separate out compound crystal after the cooling, the crystallization time is generally at 1-2 days.
In the hot capric acid mixture of the present invention, the total content of general acid〉90%, sad content is 40%-60%, more than is mass content.
Amount of substance sad in described substituted pyridines (I) and the hot capric acid mixture compares 2-5:1.
The consumption of described resolution solvent is counted 5-40ml/g with the quality of hot capric acid mixture.
The alkali lye that is used for regulating water layer pH value can be selected saturated sodium bicarbonate solution, saturated sodium carbonate solution, saturated sodium hydroxide solution etc. for use.
The structural formula of the substituted pyridines that uses among the present invention is suc as formula shown in (I), concrete, described substituted pyridines can be selected from following a kind of: 2-aminopyridine, 2 hydroxy pyrimidine, 2-amino-5 chloropyridine, 2-amino-5-bromopyridine, 2-hydroxyl-5-chloropyridine, 2-hydroxyl-5 bromopyridine.
The described separation method of concrete recommendation carries out according to following steps:
(1) in reaction vessel, add substituted pyridines (I), hot capric acid mixture and resolution solvent respectively, under agitation heat 1-2h, be cooled to room temperature, leave standstill to separating out compound crystal, the recrystallization after-filtration obtains solid, keeps filtrate; The compound crystal that obtains is dissolved in the 1N hydrochloric acid, obtains layering solution, separate organic layer A and water layer A, organic layer A is with after the saturated common salt water washing, anhydrous Na
2SO
4Drying, it is sad promptly to get monomer; The content of acid in the described hot capric acid mixture〉90%, sad content is 40%-60%; Mol ratio sad in described substituted pyridines (I) and the hot capric acid mixture is 2-5:1, and it is one of following that described resolution solvent is selected from: methyl alcohol, ethanol, acetone, ethyl acetate, and the consumption of described resolution solvent is counted 5-40ml/g with the quality of hot capric acid mixture; It is one of following that recrystallization solvent is selected from: methyl alcohol, ethanol, acetone, ethyl acetate;
(2) filtrate that step (1) is obtained is dissolved in the hydrochloric acid of 1N, obtains layering solution, separate organic layer B and water layer B;
(3) combining water layer A and water layer B are with saturated NaHCO
3Be adjusted to pH〉7, with the ethylene dichloride extraction, separation obtains organic layer and concentrates again, and the crystal of separating out after the cooling washs with less water, gets substituted pyridines (I).
Compared with prior art, present method is utilized being complementary on the topology between host molecule and the guest molecule based on the ultimate principle of supramolecule assembling, make substituted pyridines optionally with the stable molecular crystal of sad formation, thereby realize centrifugation efficiently and rapidly, its advantage mainly is:
A) efficiency ratio of Chai Fening is higher.Because the high selectivity of molecular recognition only needs primary crystallization, the yield that monomer is sad can be between 80%-95%, and its purity is between 93%-99%.
B) simple to operate, good reproducibility, implementation cost is low, is beneficial to industry and amplifies.
(4) embodiment
Further specify technical scheme of the present invention with specific embodiment below, but protection scope of the present invention is not limited thereto.
Embodiment 1
Be equipped with in the 250ml round-bottomed flask of condensing reflux pipe one, add 10.12g (0.078mol) 2-amino-5-chloropyridine, commercially available hot last of the ten Heavenly stems mixing acid (caprylic/capric=52.8/47.3) 10.03g and 200ml methyl alcohol respectively, under agitation reflux 1h is cooled to room temperature.Obtain white crystals after 2 days, filter (filtrate reservations), the recrystallizing methanol after-filtration obtains white crystal, and usefulness methanol wash 3 times (3 * 50ml), seasoning in the air.
13CNMR(125MHz，CDCl3，TMS):δ＝179.53，159.52，152.63，123.55，111.34，38.23，31.52，29.12，28.89，24.84，22.81，14.12。m.p.＝37℃。
Above-mentioned white crystal is dissolved in the 50ml1N hydrochloric acid.Obtain stratified liquid, organic layer is sad (water keeps, and reclaims 2-amino-5-chloropyridine).After the water washing of 20ml saturated common salt, anhydrous Na
2SO
4Drying obtains the sad 4.92g of liquid, yield 92.8%, and liquid chromatogram measuring purity is 98.3%.
13CNMR(125MHz，CDCl3，TMS):δ＝179.59，34.38，31.66，29.09，28.95，24.88，22.61，14.08。
Filtrate is dissolved in the hydrochloric acid of 100ml1N.Obtain layering solution and keep water.
Merge above-mentioned water, with saturated NaHCO
3Be neutralized to alkalescence (pH〉7), concentrate with dichloromethane extraction, the crystal that cooling is separated out washs with less water, 2-amino-5-chloropyridine 9.05g, the rate of recovery is 89.4%, and is reusable.
Embodiment 2
Be equipped with in the 500ml round-bottomed flask of condensing reflux pipe one, add 10.5g (0.11mol) 2-aminopyridine, commercially available suffering mixing acid (52.8/47.3) 10.1g in the last of the ten Heavenly stems and 100ml ethanol respectively, under agitation reflux 1h is cooled to room temperature.Obtain white crystals after 1 day, filter (filtrate reservations), the recrystallizing methanol after-filtration obtains white crystal, and usefulness methanol wash 3 times (3 * 50ml), seasoning in the air.Above-mentioned white crystal is dissolved in the 50ml1N hydrochloric acid, obtains layering solution, organic layer is sad (water keeps, and reclaims the 2-aminopyridine).After the water washing of 200ml saturated common salt, anhydrous Na
2SO
4Drying obtains sad 4.7g, yield 88.1%, and its purity of liquid chromatogram measuring is 96.5%.
13CNMR(125MHz，CDCl3，TMS):δ＝179.47，34.26，31.31，29.07，28.88，24.87，22.45，14.12。
Filtrate is dissolved in the hydrochloric acid of 150ml1N.Obtain layering solution and keep water.
Merge above-mentioned water, with saturated Na
2CO
3Be adjusted to alkalescence (pH〉7), concentrate with dichloromethane extraction, the crystal of separating out after the cooling washs with less water, 2-aminopyridine 9.0g, the rate of recovery is 86%, and is reusable.
Embodiment 3
Be equipped with in the 1000ml round-bottomed flask of condensing reflux pipe one, add 42.7g (0.45mol) 2 hydroxy pyrimidine, commercially available suffering mixing acid (52.8/47.3) 50.0g in the last of the ten Heavenly stems and 500ml methyl alcohol respectively, under agitation reflux 1h is cooled to room temperature.Obtain white crystals after 2 days, filter (filtrate reservations), the recrystallizing methanol after-filtration obtains white crystal, and usefulness methanol wash 3 times (3 * 50ml), seasoning in the air.Above-mentioned white crystal is dissolved in the 500ml1N hydrochloric acid.Obtain layering solution, organic layer is sad, (water keeps, and reclaims 2 hydroxy pyrimidine).After the water washing of 100ml saturated common salt, anhydrous Na
2SO
4Drying obtains the sad 24.7g of liquid, yield 94.2%, and it is 95.3% that liquid chromatography gets its purity.
13CNMR(125MHz，CDCl3，TMS):δ＝179.59，34.38，31.66，29.09，28.95，24.88，22.61，14.08。
Filtrate is dissolved in the hydrochloric acid of 500ml1N.Obtain layering solution, the water intaking layer.
Merge above-mentioned water, with saturated NaHCO
3Be adjusted to pH〉7, concentrate with dichloromethane extraction, get 2 hydroxy pyrimidine 38.8g, the rate of recovery is 90.9%, and is reusable.
Embodiment 4
Be equipped with in the 500ml round-bottomed flask of condensing reflux pipe one, add 36.5g (0.15mol) 2-hydroxyl-5-chloropyridine, suffering mixing acid (40.7/59.3) 15.0g in the last of the ten Heavenly stems and 300ml methyl alcohol respectively, under agitation reflux 1h is cooled to room temperature.Obtain white crystals after 2 days, filter (filtrate reservations), the recrystallizing methanol after-filtration obtains white crystal, and usefulness methanol wash 3 times (3 * 50ml), seasoning in the air.
Above-mentioned white crystal is dissolved in the 75ml1N hydrochloric acid.Obtain layering solution, organic layer is sad, (water keeps, and reclaims 2-hydroxyl-5-chloro-pyridine).After the water washing of 50ml saturated common salt, anhydrous Na
2SO
4Drying obtains the sad 4.8g of liquid, yield 84.5%, and its purity of liquid chromatogram measuring is 97.5%.
13CNMR(125MHz，CDCl3，TMS):δ＝180.25，35.38，23.64，30.04，29.93，25.87，23.59，15.04。
Filtrate is dissolved in the hydrochloric acid of 200ml1N.Obtain layering solution, the water intaking layer merges above-mentioned water, with saturated NaHCO
3Be adjusted to pH〉7, concentrate with dichloromethane extraction, get 2-hydroxyl-5-chloropyridine 21.7g, the rate of recovery is 94.9%, and is reusable.
Embodiment 5
Be equipped with in the 1000ml round-bottomed flask of condensing reflux pipe one, add 71.2g (0.41mol) 2-amino-5-bromopyridine, suffering mixing acid (59.5/40.5) 20.1g in the last of the ten Heavenly stems and 400ml ethyl acetate respectively, under agitation reflux 1h is cooled to room temperature.Obtain white crystals after 2 days, filter (filtrate reservations), the ethyl alcohol recrystallization after-filtration obtains white crystal, and usefulness washing with alcohol 3 times (3 * 50ml), seasoning in the air.Above-mentioned white crystal is dissolved in the 120ml1N hydrochloric acid.Obtain layering solution, organic layer is sad (water keeps, and reclaims 2-amino-5-bromo-pyridine).After the water washing of 100ml saturated common salt, anhydrous Na
2SO
4Drying obtains the sad 9.6g of liquid, yield 80.8%, and its purity of liquid chromatogram measuring is 95.1%.
13CNMR(125MHz，CDCl3，TMS):δ＝177.39，32.25，29.66，37.09，26.95，24.86，22.59，14.05。
Filtrate is dissolved in the hydrochloric acid of 400ml1N.Obtain layering solution, the water intaking layer.
Merge above-mentioned water, with saturated NaHCO
3Be adjusted to pH〉7, concentrate with dichloromethane extraction, get 2-amino-5-bromopyridine 61.6g, the rate of recovery is 86.7%, and is reusable.
Embodiment 6
Be equipped with in the 1000ml round-bottomed flask of condensing reflux pipe one, add 142.0g (0.82mol) 2-hydroxyl-5-bromopyridine, suffering mixing acid (59.5/40.5) 40.0g in the last of the ten Heavenly stems and 400ml acetone respectively, under agitation reflux 1h is cooled to room temperature.Obtain white crystals after 2 days, filter (filtrate reservations), the acetone recrystallization after-filtration obtains white crystal, and usefulness washing with acetone 3 times (3 * 50ml), seasoning in the air.Above-mentioned white crystal is dissolved in the 200ml1N hydrochloric acid.Obtain layering solution, organic layer is sad (water keeps, and reclaims 2-amino-5-bromo-pyridine).After the water washing of 100ml saturated common salt, anhydrous Na
2SO
4Drying obtains the sad 19.2g of liquid, yield 80.6%, and its purity of liquid chromatogram measuring is 96.1%.
13CNMR(125MHz，CDCl3，TMS):δ＝177.41，32.32，29.45，37.12，26.96，24.56，22.48，14.04。
Filtrate is dissolved in the hydrochloric acid of 400ml1N.Obtain layering solution, the water intaking layer.
Merge above-mentioned water, with saturated NaHCO
3Be adjusted to pH〉7, concentrate with dichloromethane extraction, get 2-amino-5-bromopyridine 112.3g, the rate of recovery is 79.1%, and is reusable.
Claims (10)
1. one kind is separated sad method from hot capric acid mixture, described separation method is: in resolution solvent, fully react down at 50-80 ℃ suc as formula substituted pyridines shown in (I) and hot capric acid mixture, leave standstill at 0-30 ℃ and to separate out compound crystal, filtration obtains compound crystal crude product and filtrate, described compound crystal crude product is used the dilute hydrochloric acid hydrolysis of concentration 2%-10% behind recrystallization, obtain layering solution, separate obtaining water layer A and organic layer A, organic layer A is sad through washing, be drying to obtain monomer; It is one of following that described resolution solvent is selected from: methyl alcohol, ethanol, acetone, ethyl acetate;
In the formula (I), R
1Represent OH or NH
2, R
2Represent Cl, Br or H.
2. separation method as claimed in claim 1, it is characterized in that described water layer A reclaims obtains substituted pyridines (I), described recovery method is: water layer is adjusted to pH value＞7 with alkali lye, then with dichloromethane extraction, concentrate, obtain substituted pyridines (I) after the cooling, crystallization.
3. separation method as claimed in claim 2, the filtrate that obtains when it is characterized in that by filtering separation compound crystal crude product is used the dilute hydrochloric acid hydrolysis of concentration 2%-10% earlier, obtain layering solution, separate obtaining water layer B and organic layer B, water layer A and water layer B merging are reclaimed substituted pyridines (I).
4. as the described separation method of one of claim 1～3, it is characterized in that total mass content＞90% of acid in the described hot capric acid mixture, sad mass content is 40%-60%.
5. as the described separation method of one of claim 1～3, it is characterized in that amount of substance sad in described substituted pyridines (I) and the hot capric acid mixture is than being 2-5:1.
6. as the described separation method of one of claim 1～3, it is characterized in that the consumption of described resolution solvent is counted 5-40ml/g with the quality of hot capric acid mixture.
7. separation method as claimed in claim 1, it is one of following to it is characterized in that recrystallization solvent is selected from: methyl alcohol, ethanol, acetone, ethyl acetate.
8. separation method as claimed in claim 2 is characterized in that described alkali lye is saturated sodium bicarbonate solution, saturated sodium carbonate solution, saturated sodium hydroxide solution.
9. separation method as claimed in claim 1 is characterized in that described substituted pyridines is one of following: 2-aminopyridine, 2 hydroxy pyrimidine, 2-amino-5-chloropyridine, 2-amino-5-bromopyridine.
10. separation method as claimed in claim 1 is characterized in that described separation method carries out according to following steps:
(1) in reaction vessel, add substituted pyridines (I), hot capric acid mixture and resolution solvent respectively, under agitation be heated to 50-80 ℃ of insulation reaction 1-2h, obtain clear soln, be cooled to room temperature, leave standstill to separating out compound crystal in 0-30 ℃, filter and obtain the compound crystal crude product, keep filtrate; Obtain layering solution in the 1N hydrochloric acid with being dissolved in behind the compound crystal crude product recrystallization that obtains, separate organic layer A and water layer A, organic layer A is with after the saturated common salt water washing, again through anhydrous Na
2SO
4It is sad to be drying to obtain monomer; The content of acid in the described hot capric acid mixture〉90%, sad content is 40%-60%; Amount of substance sad in described substituted pyridines (I) and the hot capric acid mixture is than 2-5:1, and it is one of following that described resolution solvent is selected from: methyl alcohol, ethanol, acetone, ethyl acetate, and the consumption of described resolution solvent is counted 5-40ml/g with the quality of hot capric acid mixture; It is one of following that recrystallization solvent is selected from: methyl alcohol, ethanol, acetone, ethyl acetate;
(2) filtrate that step (1) is obtained is dissolved in the hydrochloric acid of 1N, obtains layering solution, separates to obtain organic layer B and water layer B;
(3) combining water layer A and water layer B are with saturated NaHCO
3Be adjusted to pH〉7, use dichloromethane extraction again, concentrate, the crystal of separating out after the cooling washs with less water, gets substituted pyridines.
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|---|---|---|---|
| CN2008101215096A CN101381297B (en) | 2008-10-09 | 2008-10-09 | Method for separating caprylic acid from mixture of caprylic acid and capric acid |
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| CN102898258B (en) * | 2012-10-11 | 2013-10-16 | 中国工程物理研究院化工材料研究所 | Method for designing and controlling microstructure of explosive based on supramolecular assembly and disassembly |
| US10526624B2 (en) | 2016-05-26 | 2020-01-07 | Cornell University | Methods for producing caprylic acid and/or caprylate |
| CN108218691B (en) * | 2016-12-22 | 2021-06-15 | 丰益(上海)生物技术研发中心有限公司 | Method for separating fatty acid and fatty acid methyl ester |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2073112A1 (en) * | 1991-07-12 | 1993-01-13 | Gregor Deckers | Process for separating off aliphatic straight-chain compounds having terminal functional groups |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2073112A1 (en) * | 1991-07-12 | 1993-01-13 | Gregor Deckers | Process for separating off aliphatic straight-chain compounds having terminal functional groups |
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