CA1053687A - Purification of coumarin and alkylated derivatives of it - Google Patents
Purification of coumarin and alkylated derivatives of itInfo
- Publication number
- CA1053687A CA1053687A CA218,341A CA218341A CA1053687A CA 1053687 A CA1053687 A CA 1053687A CA 218341 A CA218341 A CA 218341A CA 1053687 A CA1053687 A CA 1053687A
- Authority
- CA
- Canada
- Prior art keywords
- coumarin
- weight
- process according
- basic compound
- alkali metal
- 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.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D311/00—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only hetero atom, condensed with other rings
- C07D311/02—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only hetero atom, condensed with other rings ortho- or peri-condensed with carbocyclic rings or ring systems
- C07D311/04—Benzo[b]pyrans, not hydrogenated in the carbocyclic ring
- C07D311/06—Benzo[b]pyrans, not hydrogenated in the carbocyclic ring with oxygen or sulfur atoms directly attached in position 2
- C07D311/08—Benzo[b]pyrans, not hydrogenated in the carbocyclic ring with oxygen or sulfur atoms directly attached in position 2 not hydrogenated in the hetero ring
- C07D311/10—Benzo[b]pyrans, not hydrogenated in the carbocyclic ring with oxygen or sulfur atoms directly attached in position 2 not hydrogenated in the hetero ring unsubstituted
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Pyrane Compounds (AREA)
- Plural Heterocyclic Compounds (AREA)
- Cosmetics (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Fats And Perfumes (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Contaminated coumarin optionally alkylated, is purified by treatment with 0.001 to 1 mole equivalent of a solution of an inorganic base or a salt giving a similar basic reaction at a temperature of 20-150 °C, the coumarin containing layer so formed is washed with water at 20-150 °C and the purified coumarin is recovered. Coumarin so purified has an extremely high purity, generally below 100° Hazen and preferably below 70° Hazen, and is useful directly in the perfume and fragrance industry.
Contaminated coumarin optionally alkylated, is purified by treatment with 0.001 to 1 mole equivalent of a solution of an inorganic base or a salt giving a similar basic reaction at a temperature of 20-150 °C, the coumarin containing layer so formed is washed with water at 20-150 °C and the purified coumarin is recovered. Coumarin so purified has an extremely high purity, generally below 100° Hazen and preferably below 70° Hazen, and is useful directly in the perfume and fragrance industry.
Description
~ o 5 3 ~ 8 7 2662 This invention relates to a process for purifying contaminated coumarin or alkylated coumarin of the general formula ~1 3 ~ ~ R6 wherein each of the substituents R1 to R6 may be hydrogen or a C1-C5 alkyl group and the total number of carbon atoms of the substituents is not more than 10.
The preparation of such compounds is described and claimed in British Patent No. 1,368,941 and Canadian patent application 179.601 Such compounds are of particular importance in the fragrance industry, and thus have to be very pure. The main standard of purity generally required is that the colour of the coumarin should be less than 100, preferably less than 70 Hazen. Common impurities in coumarin include 3,4-dihydrocoumarin, ethyl phenol, dihydrocinnamic acid, and e~ter of ethyl phenol and dihydrocinnamic acid. Several methods of purifying coumarin are known e.g., distillation and recrystallization 16 (see for example Kirk-Ottmer, Encyclopedia of Chemical Technology, 2nd edition, volume 6). Such methods however yield a coumarin that is not sufficiently pure for use in the fragrance industry, and for instance the colour of the coumarin thus purified is between 125 and 250 Hazen.
According to another known method coumarin can be obtained in a purified state by successively separating the resinous components from the crude coumarin, dissolving the remaining coumarin in concentrated sulphuric acid, passing air through the resulting solution at high temperature, precipitating the coumarin by treating the solution with water, washing and neutralizing the precipitate and distilling it at reduced pressure. This process is complicated, and provides a product having a colour of about 200 Hazen, and furthermore a considerable part of the starting material gets lost.
In another process describcd in Berichte, Volume 70, 19~7, p. 237, coumarin is recovered from a roaction mixture obtained by dehydrogenation of dihydrocoumarin, the reaction mixture is distilled, and the distil]ate is dissolved in aqueous potassium hydroxide. The solution thus obtained is treated with an acid and subjected to an extraction with ether. This laborious process yields a coumarin also that is not sufficiently pure in practice, and mor~over the dissolving of the mixture in potassium hydroxide requires a very large amount of potassium hydroxide, viz. about 2.5 mole potassium hydroxide per 100 grams of reaction mixture.
The present invention provides a process for purifying a contaminated coumarin or alkylated coumarin of general formula Rl .
. R2 ~ ~ . ::
R3 ~ R6 wherein each of the substituents R1 to R6 is hydrogen or a C1-C5 alkyl group and the total number of carbon atoms of the substituents is not more than 10, comprising treating the contaminated coumarin with an aqueous solution of a -15 basic compound at a temperature between 20 and 150 C, separating the aqueous layer thus formed from the layer containing the coumarin, and ' wRshing the latter layer with water at a temperature between 20 and 150 CC~
! and recovering purified coumarin compound from the resulting washed layer.
~ The aqueous basic solution used may be for instance an aqueous solution i 20 o~ an alkali metal or alkaline-earth metal hydroxide, e.g., NaOH, KOH, LiOH, Mg(OH)2, Ca(OH)2, and Ba(OH)2. Other solutions which may be used according to the invention are solutions of sodium or potassium carbonate, sodium or I potassium acetate, and sodium or potassium benzoate. The amount of basic ¦ compound in the said solution is preferably between 0.001 and 1 mole 1 25 equivalent of basic compound per 100 grams of contaminated coumarin. The optimum amount is determined in part by the amount and the nature of the impurities. In most instances it is sufficient to use a solution containing between 0.005 to 0.1 mole equivalent of basic compound per 100 grams of contaminated coumarin.
. , .
: , . ' , ^
-`` 1053687 The conc~ntratic)n of the so]ution may also be within widc limits, e.g. containing betwecn 0 1 and 10 % by wcight of basic compound. The temperature at which the treatment of the contaminated coumarin and the washing with water is effected is preferably of a temperature of from 70 to 100 C. The pressure is not critical and the process may be effected at atmospheric pressure.
The purified coumarin compound may be recovered from the layer that has been washed with water in various ways, preferably by distillation.
Coumarins obtained in the process according to the invention are very pure and can be used as such in the fragrance industry, the colour of the product j 10 being below 70 Hazen. If it is desired to have extremely pure coumarin, this may be obtained by recrystallizing the coumarin product recovered by distillation, e,g. from ethanol.
The following examples of the invention are provided, , b Exam~le I
186 grams of impure coumarin and 186 grams of an aqueous sodium hydroxide solution (0.75 % by weight of NaOH) were introduced into a 500-ml ¦ flask provided with a stirrer and a reflux condenser.
¦ The impure coumarin contained 2 % by weight of 3.4-dihydrocoumarin, 0.2 % by weight of ethyl phenol, 0.3 % by weight of dihydrocinnamic acid and -ao 0,5 % by weight oi high-boiling impurities mainly the ester of ethyl phenol ` and dihydrocinnamic acid. -The mixture in the ilask was heated with stirring at 100 C for -1 hour under reflux. Subsequently the layer containing coumarin was separated ~rom the aqueous layer and the organic layer was washed twice with a total of . ~, . .
25 180 ml of water. 170 grams o~ coumarin were recovered from the washed product:~ ''~:, , ` . : -by di6tillation.
The purified coumarin product thus obtained Qontained . more than 99,9 % of coumarin, together wlth 0.01 % by weight of ethyl phenol, 0.03 % by weight of dihydrocinnamic acid, and 0.03 % by weight of high-boiling - 30 impurities.
.
.~
. .
i `- 1053687 The colour o:E the product was 65 llazen.
70 grams of the coumarin product were rccrystallized from 250 m] of 50 % cthanol. The coumarin was then filtered and washed twice with a total of 50 ml of 20 % ethanol. The product was dried and yielded 62 grams of highly purifiod coumarin of more than 99.95 % purity, together with less than 0.01 % by weight of dihydrocinnamic acid and 0.01 % by weight of high-boiling impurities.
The colour of the product was 60 Hazen.
~ .
Example II
40 grams of impurc coumarin and 40 grams of a solution of sodium carbonate in water (0.9 % by weight of Na2C03) were introduced into a 100-ml flask provided with a stirrer and a reflux condenser.
' The impure coumarin contained 97 % by weight of coumarin, together with 2 % by weight of 3,4-dihydrocoumarin,0.2 % by weight of ethyl phenol, 0.3 % by weight of dihydrocinnamic acid and 0.5 % by weight of high-boiling impurities. The mixture in the flask was heated with stirring at 100 C for 1 hour under reflux. Subsequently the layer containing coumarin was separated irom the layer containing the basic compound and washed twice with a total I of 40 ml of water. The organic layer was distilled and 36 grams of purified 1, 20 coumarin were obtained of more than 99.9 % by weight of coumarin, together with 0.01 % by weight of ethyl phenol, less than 0.01 % by weight of dihydrooinnamic acid and 0,02 % by weight of high-boiling impurities.
¦ The colour of the product was 68 Hazen.
Comparative Experiment 100 grams of impure coumarin having the same composition as the impure coumarin used in Example I and 100 grams of sulphuric acid (80 % by ¦ weight of H2S04) were introduced into a 250-ml flask provided with a stirrer, a reflux cooler and a gas-inlet tube. The mixture in the flask was heated at 110 C for 2 hours with stirring and 135 litres/hour of air passed through the contents, -5 _ .
The reaction mixture was then poured into 200 ml of water whoreby a precipitate of coumarin was formod. The precipitate was filtered off, washed with water and distilled at reduced pressure.
The coulnarin product obtained containcd 99.5 % by weight of coumarin together with 0.1 % by weight of ethyl phenol, 0.2 % by weight of 3.4-dihydro-coumarin, 0,02 % by weight of dihydrocinnamic acid and 0.18 % by weight of high-boiling impurities.
The colour of ~he product was 20 ~ hazen.
' ~
'~ ' ' .
~ - 6 ., .
The preparation of such compounds is described and claimed in British Patent No. 1,368,941 and Canadian patent application 179.601 Such compounds are of particular importance in the fragrance industry, and thus have to be very pure. The main standard of purity generally required is that the colour of the coumarin should be less than 100, preferably less than 70 Hazen. Common impurities in coumarin include 3,4-dihydrocoumarin, ethyl phenol, dihydrocinnamic acid, and e~ter of ethyl phenol and dihydrocinnamic acid. Several methods of purifying coumarin are known e.g., distillation and recrystallization 16 (see for example Kirk-Ottmer, Encyclopedia of Chemical Technology, 2nd edition, volume 6). Such methods however yield a coumarin that is not sufficiently pure for use in the fragrance industry, and for instance the colour of the coumarin thus purified is between 125 and 250 Hazen.
According to another known method coumarin can be obtained in a purified state by successively separating the resinous components from the crude coumarin, dissolving the remaining coumarin in concentrated sulphuric acid, passing air through the resulting solution at high temperature, precipitating the coumarin by treating the solution with water, washing and neutralizing the precipitate and distilling it at reduced pressure. This process is complicated, and provides a product having a colour of about 200 Hazen, and furthermore a considerable part of the starting material gets lost.
In another process describcd in Berichte, Volume 70, 19~7, p. 237, coumarin is recovered from a roaction mixture obtained by dehydrogenation of dihydrocoumarin, the reaction mixture is distilled, and the distil]ate is dissolved in aqueous potassium hydroxide. The solution thus obtained is treated with an acid and subjected to an extraction with ether. This laborious process yields a coumarin also that is not sufficiently pure in practice, and mor~over the dissolving of the mixture in potassium hydroxide requires a very large amount of potassium hydroxide, viz. about 2.5 mole potassium hydroxide per 100 grams of reaction mixture.
The present invention provides a process for purifying a contaminated coumarin or alkylated coumarin of general formula Rl .
. R2 ~ ~ . ::
R3 ~ R6 wherein each of the substituents R1 to R6 is hydrogen or a C1-C5 alkyl group and the total number of carbon atoms of the substituents is not more than 10, comprising treating the contaminated coumarin with an aqueous solution of a -15 basic compound at a temperature between 20 and 150 C, separating the aqueous layer thus formed from the layer containing the coumarin, and ' wRshing the latter layer with water at a temperature between 20 and 150 CC~
! and recovering purified coumarin compound from the resulting washed layer.
~ The aqueous basic solution used may be for instance an aqueous solution i 20 o~ an alkali metal or alkaline-earth metal hydroxide, e.g., NaOH, KOH, LiOH, Mg(OH)2, Ca(OH)2, and Ba(OH)2. Other solutions which may be used according to the invention are solutions of sodium or potassium carbonate, sodium or I potassium acetate, and sodium or potassium benzoate. The amount of basic ¦ compound in the said solution is preferably between 0.001 and 1 mole 1 25 equivalent of basic compound per 100 grams of contaminated coumarin. The optimum amount is determined in part by the amount and the nature of the impurities. In most instances it is sufficient to use a solution containing between 0.005 to 0.1 mole equivalent of basic compound per 100 grams of contaminated coumarin.
. , .
: , . ' , ^
-`` 1053687 The conc~ntratic)n of the so]ution may also be within widc limits, e.g. containing betwecn 0 1 and 10 % by wcight of basic compound. The temperature at which the treatment of the contaminated coumarin and the washing with water is effected is preferably of a temperature of from 70 to 100 C. The pressure is not critical and the process may be effected at atmospheric pressure.
The purified coumarin compound may be recovered from the layer that has been washed with water in various ways, preferably by distillation.
Coumarins obtained in the process according to the invention are very pure and can be used as such in the fragrance industry, the colour of the product j 10 being below 70 Hazen. If it is desired to have extremely pure coumarin, this may be obtained by recrystallizing the coumarin product recovered by distillation, e,g. from ethanol.
The following examples of the invention are provided, , b Exam~le I
186 grams of impure coumarin and 186 grams of an aqueous sodium hydroxide solution (0.75 % by weight of NaOH) were introduced into a 500-ml ¦ flask provided with a stirrer and a reflux condenser.
¦ The impure coumarin contained 2 % by weight of 3.4-dihydrocoumarin, 0.2 % by weight of ethyl phenol, 0.3 % by weight of dihydrocinnamic acid and -ao 0,5 % by weight oi high-boiling impurities mainly the ester of ethyl phenol ` and dihydrocinnamic acid. -The mixture in the ilask was heated with stirring at 100 C for -1 hour under reflux. Subsequently the layer containing coumarin was separated ~rom the aqueous layer and the organic layer was washed twice with a total of . ~, . .
25 180 ml of water. 170 grams o~ coumarin were recovered from the washed product:~ ''~:, , ` . : -by di6tillation.
The purified coumarin product thus obtained Qontained . more than 99,9 % of coumarin, together wlth 0.01 % by weight of ethyl phenol, 0.03 % by weight of dihydrocinnamic acid, and 0.03 % by weight of high-boiling - 30 impurities.
.
.~
. .
i `- 1053687 The colour o:E the product was 65 llazen.
70 grams of the coumarin product were rccrystallized from 250 m] of 50 % cthanol. The coumarin was then filtered and washed twice with a total of 50 ml of 20 % ethanol. The product was dried and yielded 62 grams of highly purifiod coumarin of more than 99.95 % purity, together with less than 0.01 % by weight of dihydrocinnamic acid and 0.01 % by weight of high-boiling impurities.
The colour of the product was 60 Hazen.
~ .
Example II
40 grams of impurc coumarin and 40 grams of a solution of sodium carbonate in water (0.9 % by weight of Na2C03) were introduced into a 100-ml flask provided with a stirrer and a reflux condenser.
' The impure coumarin contained 97 % by weight of coumarin, together with 2 % by weight of 3,4-dihydrocoumarin,0.2 % by weight of ethyl phenol, 0.3 % by weight of dihydrocinnamic acid and 0.5 % by weight of high-boiling impurities. The mixture in the flask was heated with stirring at 100 C for 1 hour under reflux. Subsequently the layer containing coumarin was separated irom the layer containing the basic compound and washed twice with a total I of 40 ml of water. The organic layer was distilled and 36 grams of purified 1, 20 coumarin were obtained of more than 99.9 % by weight of coumarin, together with 0.01 % by weight of ethyl phenol, less than 0.01 % by weight of dihydrooinnamic acid and 0,02 % by weight of high-boiling impurities.
¦ The colour of the product was 68 Hazen.
Comparative Experiment 100 grams of impure coumarin having the same composition as the impure coumarin used in Example I and 100 grams of sulphuric acid (80 % by ¦ weight of H2S04) were introduced into a 250-ml flask provided with a stirrer, a reflux cooler and a gas-inlet tube. The mixture in the flask was heated at 110 C for 2 hours with stirring and 135 litres/hour of air passed through the contents, -5 _ .
The reaction mixture was then poured into 200 ml of water whoreby a precipitate of coumarin was formod. The precipitate was filtered off, washed with water and distilled at reduced pressure.
The coulnarin product obtained containcd 99.5 % by weight of coumarin together with 0.1 % by weight of ethyl phenol, 0.2 % by weight of 3.4-dihydro-coumarin, 0,02 % by weight of dihydrocinnamic acid and 0.18 % by weight of high-boiling impurities.
The colour of ~he product was 20 ~ hazen.
' ~
'~ ' ' .
~ - 6 ., .
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for purifying a contaminated coumarin or alkylated coumarin of general formula wherein each of the substituents R1 to R6 is hydrogen or a C1-C5 alkyl group and the total number of carbon atoms of the substituents is not more than 10, comprising treating the con-taminated coumarin with an aqueous solution of a basic compound at a temperature between 20° and 150°C, separating the aqueous layer thus formed from the layer containing the coumarin, and washing the latter layer with water at a temperature between 20° and 150°C, and recovering purified coumarin compound from the resulting washed layer.
2. A process according to claim 1, wherein the said solution of the basic compound contains from 0.001 to 1 mole equivalent of basic compound per 100 grams of contaminated coumarin.
3. A process according to claim 1, or claim 2, wherein the said basic compound is an alkali metal hydroxide or alkali metal carbonate.
4. A process according to claim 1, wherein after the washing step, the coumarin compound is recovered by distillation.
5. A process according to claim 4, wherein the coumarin compound obtained by the said distillation is recrystallized.
6. A process according to claim 4, or claim 5, wherein the said basic compound is an alkali metal hydroxide or alkali metal carbonate.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL7401012A NL7401012A (en) | 1974-01-25 | 1974-01-25 | PURIFICATION OF CUMARIN AND ITS ALKYLATED DERIVATIVES. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1053687A true CA1053687A (en) | 1979-05-01 |
Family
ID=19820611
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA218,341A Expired CA1053687A (en) | 1974-01-25 | 1975-01-21 | Purification of coumarin and alkylated derivatives of it |
Country Status (11)
| Country | Link |
|---|---|
| JP (1) | JPS606950B2 (en) |
| BE (1) | BE824780A (en) |
| CA (1) | CA1053687A (en) |
| CH (1) | CH593276A5 (en) |
| DE (1) | DE2502690C2 (en) |
| ES (1) | ES434112A1 (en) |
| FR (1) | FR2259101B1 (en) |
| GB (1) | GB1443406A (en) |
| IT (1) | IT1026457B (en) |
| NL (1) | NL7401012A (en) |
| SE (1) | SE417609B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3191333B2 (en) * | 1990-12-19 | 2001-07-23 | 住友化学工業株式会社 | Method for producing 3,4-dihydrocoumarin |
| JP6496705B2 (en) | 2016-12-16 | 2019-04-03 | 株式会社ダイセル | Papermaking sheet and method for producing papermaking sheet |
-
1974
- 1974-01-25 NL NL7401012A patent/NL7401012A/en not_active Application Discontinuation
-
1975
- 1975-01-20 GB GB236975A patent/GB1443406A/en not_active Expired
- 1975-01-21 CA CA218,341A patent/CA1053687A/en not_active Expired
- 1975-01-22 CH CH73975A patent/CH593276A5/xx not_active IP Right Cessation
- 1975-01-23 DE DE2502690A patent/DE2502690C2/en not_active Expired
- 1975-01-23 JP JP50010123A patent/JPS606950B2/en not_active Expired
- 1975-01-24 FR FR7502247A patent/FR2259101B1/fr not_active Expired
- 1975-01-24 IT IT47831/75A patent/IT1026457B/en active
- 1975-01-24 BE BE152713A patent/BE824780A/en unknown
- 1975-01-24 ES ES434112A patent/ES434112A1/en not_active Expired
- 1975-01-24 SE SE7500786A patent/SE417609B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| NL7401012A (en) | 1975-07-29 |
| BE824780A (en) | 1975-07-24 |
| JPS50106967A (en) | 1975-08-22 |
| DE2502690C2 (en) | 1984-05-10 |
| JPS606950B2 (en) | 1985-02-21 |
| GB1443406A (en) | 1976-07-21 |
| CH593276A5 (en) | 1977-11-30 |
| SE7500786L (en) | 1975-07-28 |
| ES434112A1 (en) | 1976-12-16 |
| FR2259101B1 (en) | 1978-02-24 |
| DE2502690A1 (en) | 1975-07-31 |
| IT1026457B (en) | 1978-09-20 |
| SE417609B (en) | 1981-03-30 |
| FR2259101A1 (en) | 1975-08-22 |
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