DE544590C - Process for the preparation of inactive menthol - Google Patents

Process for the preparation of inactive menthol

Info

Publication number
DE544590C
DE544590C DER62190D DER0062190D DE544590C DE 544590 C DE544590 C DE 544590C DE R62190 D DER62190 D DE R62190D DE R0062190 D DER0062190 D DE R0062190D DE 544590 C DE544590 C DE 544590C
Authority
DE
Germany
Prior art keywords
menthol
inactive
preparation
mixture
inactive menthol
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
Application number
DER62190D
Other languages
German (de)
Inventor
Dr Karl Schoellkopf
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
RHEINISCHE KAMPFER FABRIK
Original Assignee
RHEINISCHE KAMPFER FABRIK
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by RHEINISCHE KAMPFER FABRIK filed Critical RHEINISCHE KAMPFER FABRIK
Priority to DER62190D priority Critical patent/DE544590C/en
Application granted granted Critical
Publication of DE544590C publication Critical patent/DE544590C/en
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C35/00—Compounds having at least one hydroxy or O-metal group bound to a carbon atom of a ring other than a six-membered aromatic ring
    • C07C35/02—Compounds having at least one hydroxy or O-metal group bound to a carbon atom of a ring other than a six-membered aromatic ring monocyclic
    • C07C35/08—Compounds having at least one hydroxy or O-metal group bound to a carbon atom of a ring other than a six-membered aromatic ring monocyclic containing a six-membered rings
    • C07C35/12—Menthol
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
    • E04B2/00—Walls, e.g. partitions, for buildings; Wall construction with regard to insulation; Connections specially adapted to walls
    • E04B2/84—Walls made by casting, pouring, or tamping in situ

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Fats And Perfumes (AREA)
  • Cosmetics (AREA)

Description

Verfahren zur Darstellung von inaktivem Menthol Das Hauptpatent stellt ein Verfahren zur Darstellung von inaktivem Menthol, dem Racemat des natürlichen Menthols, unter Schutz, bei dem aus dem durch Hydrierung des Thymols erhaltenen Gemisch von inaktivem Menthol und seinen Isomeren das erstere durch Ausfrieren abgetrennt wird, wonach das abfallende flüssige Gemisch der Mentholisomeren mit dehydrierenden Katalysatoren behandelt wird, die hierbei erhaltenen Ketone in Gegenwart von hydrierenden Katalysatoren erneut der Einwirkung von Wasserstoff unter Druck ausgesetzt werden und aus dem erhaltenen Mentholgemisch wiederum das inaktive Menthol durch Ausfrieren ausgeschieden wird. Es hat sich nun gezeigt, daß die Trennung des inaktiven Menthols (des Racemats des natürlichen Menthols) von dem flüssigen Gemisch der Mentholisomeren auch durch fraktionierte Destillation mit oder ohne Vakuum erreicht werden kann. Das ursprüngliche Hydrierungsprodukt des Thymols zeigt als Gemisch verschiedener Menthole ein Siedeintervall von 2r2 bis 2z8° C bei atmosphärischem Druck entsprechend 95 bis ioo° bei einem Vakuum von io mm. i kg eines solchen Hydrierungsprodukts kann bei der fraktionierten Destillation in folgende Fraktionen zerlegt werden I. Fraktion 340 g flüssiges isomeres Mentliolgemisch Il. - Zoo g isomeres Mentholgemisch (F. z5') 11i. - 150 g hochprozentiges Menthol F. 23,5° iV. - 80 g - - F. 27,5° V. - 200 g - - F. 32,5° VI. - 309 - - F. 33:50 Aus den mittleren Fraktionen läßt sich durch erneute fraktionierte Destillation ebenfalls höher schmelzendes kristallisiertes Menthol gewinnen. Bei einem kontinuierlichen Destillationsverfahren, bei dem die mittleren Fraktionsanteile mit dem ursprünglichen Hydrierungsprodukt zusammen erneuter Fraktionierung unterworfen werden, läßt sich so aus dem Thymolhydrierungsprodukt 5o bis 6o °/" an kristallisiertem - inaktiqen Menthol vom Schmelzpunkt 3o bis 34°'gewinnen.Process for the preparation of inactive menthol The main patent provides a process for the preparation of inactive menthol, the racemate of natural menthol, under protection, in which the mixture of inactive menthol and its isomers obtained by hydrogenation of the thymol is separated by freezing out the former the falling liquid mixture of menthol isomers is treated with dehydrogenating catalysts, the ketones obtained in this way are again exposed to the action of hydrogen under pressure in the presence of hydrogenating catalysts and the inactive menthol is again eliminated from the resulting menthol mixture by freezing. It has now been shown that the separation of the inactive menthol (the racemate of natural menthol) from the liquid mixture of the menthol isomers can also be achieved by fractional distillation with or without vacuum. The original hydrogenation product of thymol, as a mixture of different mentholes, has a boiling range of 2r2 to 2z8 ° C at atmospheric pressure, corresponding to 95 to 100 ° at a vacuum of 10 mm. 1 kg of such a hydrogenation product can be broken down into the following fractions in the fractional distillation I. Fraction 340 g of liquid isomeric Mentliol mixture Il. - Zoo g isomeric menthol mixture (F. z5 ') 11i. - 150 g high percentage menthol F. 23.5 ° iV. - 80 g - - F. 27.5 ° V. - 200 g - - F. 32.5 ° VI. - 309 - - Q.33: 5 0 Higher melting crystallized menthol can likewise be obtained from the middle fractions by renewed fractional distillation. In a continuous distillation process in which the average fractions are subjected to renewed fractionation together with the original hydrogenation product, from the thymol hydrogenation product 50 to 60 ° / "of crystallized - inactive menthol with a melting point of 30 to 34 °" can be obtained.

Das flfitssige Gemisch der Mentholisomeren wird nach dem Verfahren des Hauptpatents 489 8Ig durch Behandlung- mit dehydrierenden Katalysatoren und anschließender erneuter Hydrierung mit Katalysatoren unter Druck oder aber nach dem Verfahren des Zusatzpatents 493 268 durch Erhitzen mit Alkalimetallen bzw. Mentholalkalien an inaktivem Menthol angereichert und das angereicherte Produkt für sich oder zusammen mit dem ursprünglichen Hydrierungsprodukt einer erneuten Fraktionierung unterworfen, so daß eine restlose Überführung in inaktives Menthol erreicht wird.The liquid mixture of menthol isomers is enriched in inactive menthol according to the process of main patent 489 8Ig by treatment with dehydrating catalysts and subsequent renewed hydrogenation with catalysts under pressure or in accordance with the process of additional patent 493 268 by heating with alkali metals or menthol alkalis, and the enriched menthol The product alone or together with the original hydrogenation product is subjected to renewed fractionation, so that a complete conversion into inactive menthol is achieved.

Claims (1)

PATENTANSPRUCH: Verfahren zur Darstellung von inaktivem Menthol, dem Racemat des natürlichen Menthols, nach Patent ¢89 81g, dadurch gekennzeichnet, daß man die Abtrennung des inaktiven Menthols aus durch Hydrierung des Thymols erhaltenen Mentholgemischen durch fraktionierte Destillation an Stelle des Ausfrierens vornimmt. PATENT CLAIM: Process for the preparation of inactive menthol, the racemate of natural menthol, according to Patent [89] 81g, characterized in that the inactive menthol is separated from menthol mixtures obtained by hydrogenation of the thymol by fractional distillation instead of freezing.
DER62190D 1922-10-11 1922-10-11 Process for the preparation of inactive menthol Expired DE544590C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DER62190D DE544590C (en) 1922-10-11 1922-10-11 Process for the preparation of inactive menthol

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DER62190D DE544590C (en) 1922-10-11 1922-10-11 Process for the preparation of inactive menthol

Publications (1)

Publication Number Publication Date
DE544590C true DE544590C (en) 1932-02-19

Family

ID=7411851

Family Applications (1)

Application Number Title Priority Date Filing Date
DER62190D Expired DE544590C (en) 1922-10-11 1922-10-11 Process for the preparation of inactive menthol

Country Status (1)

Country Link
DE (1) DE544590C (en)

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