CH152607A - Process for the preparation of racemic menthol. - Google Patents
Process for the preparation of racemic menthol.Info
- Publication number
- CH152607A CH152607A CH152607DA CH152607A CH 152607 A CH152607 A CH 152607A CH 152607D A CH152607D A CH 152607DA CH 152607 A CH152607 A CH 152607A
- Authority
- CH
- Switzerland
- Prior art keywords
- preparation
- racemic menthol
- menthol
- thymol
- racemic
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims description 4
- 238000002360 preparation method Methods 0.000 title claims description 3
- NOOLISFMXDJSKH-KXUCPTDWSA-N (-)-Menthol Chemical compound CC(C)[C@@H]1CC[C@@H](C)C[C@H]1O NOOLISFMXDJSKH-KXUCPTDWSA-N 0.000 title claims 2
- MGSRCZKZVOBKFT-UHFFFAOYSA-N thymol Chemical class CC(C)C1=CC=C(C)C=C1O MGSRCZKZVOBKFT-UHFFFAOYSA-N 0.000 claims description 8
- 239000005844 Thymol Substances 0.000 claims description 4
- 229960000790 thymol Drugs 0.000 claims description 4
- 238000009903 catalytic hydrogenation reaction Methods 0.000 claims description 3
- 229910052783 alkali metal Inorganic materials 0.000 claims description 2
- -1 alkali metal salts Chemical class 0.000 claims description 2
- NOOLISFMXDJSKH-UTLUCORTSA-N (+)-Neomenthol Chemical compound CC(C)[C@@H]1CC[C@@H](C)C[C@@H]1O NOOLISFMXDJSKH-UTLUCORTSA-N 0.000 description 4
- NOOLISFMXDJSKH-UHFFFAOYSA-N DL-menthol Natural products CC(C)C1CCC(C)CC1O NOOLISFMXDJSKH-UHFFFAOYSA-N 0.000 description 4
- 229940041616 menthol Drugs 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 238000005984 hydrogenation reaction Methods 0.000 description 2
- 150000002989 phenols Chemical class 0.000 description 2
- 230000001476 alcoholic effect Effects 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 150000001447 alkali salts Chemical class 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000004508 fractional distillation Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
Verfahren zur Darstellung von racemischem Henthol. Bekanntlich werden ein- oder mehrfach substituierte Phenole durch katalytische Hy drierung in ein Gemenge cistransisomerer hydroaromatischer Alkohole übergeführt.
Es wurde gefunden, dass man vorwiegend die transisomeren Verbindungen erhält, wenn man statt der freien Phenole ihre Alkali salze in wässeriger oder alkoholischer Lö sung der Reduktion mit Hydriei@zngskataly- satoren unterwirft.
Das ist von grosser technischer Bedeu tung für die Darstellung des. Menthols, da das Menthol ein Trans.derivat ist. Man erhält gemäss d-em Verfahren der vorliegenden Er findung somit durch katalytisches Hydrieren von Lösungen der Alkalisalze des Thymols das Racemat des natürlichen Menthols.
<I>Beispiel:</I> Eine etwa 30%ige Lösung von Thymol in überschüssiger Natronlauge wird mit etwa 5 % des Thymolgewichtes eines Hydrierungs- katalysators bei<B>190</B> bis 210' der Einwir- kung von Wasserstoff unterworfen. Nach Aufnahme der für 6 Atome Wasserstoff berechneten Wasserstoffmenge bleibt die Re aktion stehen. Nach Abkühlung wird die auf der alkalischen Lösung schwimmende Schicht abgetrennt. Beim Aufarbeiten durch fraktionierte Destillation erhält man neben geringen.
Mengen Mentlion, die im nächsten Arbeitsgang mit verarbeitet werden können, hauptsächlich das Ilacemat, des na türlichen Menthols.
Process for the preparation of racemic henthol. It is known that mono- or polysubstituted phenols are converted into a mixture of cistransisomeric hydroaromatic alcohols by catalytic hydrogenation.
It has been found that predominantly the trans isomeric compounds are obtained if, instead of the free phenols, their alkali salts are subjected to reduction with hydrogenation catalysts in aqueous or alcoholic solution.
This is of great technical importance for the presentation of menthol, since menthol is a trans derivative. According to the method of the present invention, the racemate of natural menthol is thus obtained by catalytic hydrogenation of solutions of the alkali metal salts of thymol.
<I> Example: </I> An approximately 30% solution of thymol in excess sodium hydroxide solution is subjected to the action of hydrogen with approximately 5% of the thymol weight of a hydrogenation catalyst at <B> 190 </B> to 210 ' . After taking up the amount of hydrogen calculated for 6 atoms of hydrogen, the reaction stops. After cooling, the layer floating on the alkaline solution is separated. When working up by fractional distillation, in addition to low levels, are obtained.
Amounts of mentlion that can be processed in the next step, mainly the ilacemate, the natural menthol.
Claims (1)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE152607X | 1930-01-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CH152607A true CH152607A (en) | 1932-02-15 |
Family
ID=5675156
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CH152607D CH152607A (en) | 1930-01-25 | 1930-12-22 | Process for the preparation of racemic menthol. |
Country Status (1)
| Country | Link |
|---|---|
| CH (1) | CH152607A (en) |
-
1930
- 1930-12-22 CH CH152607D patent/CH152607A/en unknown
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