DE858564C - Process for the production of dihydropyran - Google Patents

Process for the production of dihydropyran

Info

Publication number
DE858564C
DE858564C DEC2463D DEC0002463D DE858564C DE 858564 C DE858564 C DE 858564C DE C2463 D DEC2463 D DE C2463D DE C0002463 D DEC0002463 D DE C0002463D DE 858564 C DE858564 C DE 858564C
Authority
DE
Germany
Prior art keywords
dihydropyran
production
yield
contact
french patent
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
DEC2463D
Other languages
German (de)
Inventor
Ernst Dr Korten
Heinrich Dr Ritter
Werner Dr Zerweck
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.)
Cassella Farbwerke Mainkur AG
Original Assignee
Cassella Farbwerke Mainkur AG
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 Cassella Farbwerke Mainkur AG filed Critical Cassella Farbwerke Mainkur AG
Priority to DEC2463D priority Critical patent/DE858564C/en
Application granted granted Critical
Publication of DE858564C publication Critical patent/DE858564C/en
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D309/00—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only ring hetero atom, not condensed with other rings
    • C07D309/16—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only ring hetero atom, not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member
    • C07D309/18—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only ring hetero atom, not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member containing only hydrogen and carbon atoms in addition to the ring hetero atom

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Catalysts (AREA)

Description

Verfahren zur Herstellung von Dihydropyran R. Paul gibt im »Bull. Soc. Chim. de France«, Jahrg. 1933, 4. Reihe, Bd. 53, S. 1489 ff., an, daß er bei der katalytischen Dehydratisierung von Tetrahydrofurfuralkohol in Gegenwart von handelsüblichen Aluminiumverbindungen bei Temperaturen von 38o° unter starker, von Zersetzungsprodukten herrührender Gasentwicklung Dihydropyran in einer Ausbeute von im besten Fall 44 "/, der Theorie erhalten hat.Process for the production of dihydropyran R. Paul gives in »Bull. Soc. Chim. de France ', year 1933, 4th series, vol. 53, p. 1489 ff the catalytic dehydration of tetrahydrofurfural alcohol in the presence of commercial aluminum compounds at temperatures of 38o ° under strong, of Dihydropyran gas evolution resulting from decomposition products in one yield of 44 "/ at best, the theory has received.

Es wurde nun gefunden, daß man bei diesem Verfahren die Ausbeute an reinem Dihydropyran mehr als verdoppeln kann, wenn man die Dehydratisierung des Tetrahydrofurfuralkohols in Gegenwart einer kolloidalen Form von Aluminiumhydroxyd vornimmt, die gemäß Verfahren der französischen Patentschrift 775 821 durch Umsetzung von Aluminiumsalzen inetwa stöchiometrischemVerhältnis mit die Hydroxydbildung herbeiführenden Mitteln in der Weise erhalten wird, daß das erhaltene Hydroxyd von den bei der Zersetzung entstandenen Salzen befreit und einer Behandlung mit Peptisationsmitteln unterworfen wird.It has now been found that in this process, the yield of pure dihydropyran can more than double if you dehydrate the Tetrahydrofurfural alcohol in the presence of a colloidal form of aluminum hydroxide undertakes, according to the method of French patent 775 821 by implementation of aluminum salts in an approximately stoichiometric ratio with the hydroxide formation Means is obtained in such a way that the hydroxide obtained from the decomposition liberated salts formed and subjected to a treatment with peptizers will.

Es ist dann möglich, die Reaktion schon bei Temperaturen von 28o bis 3oo° durchzuführen, was an sich schon einen Vorteil bedeutet. Die Gasentwicklung wird unter diesen Reaktionsbedingungen vollkommen vermieden.It is then possible to start the reaction at temperatures from 28o to To carry out 3oo °, which in itself means an advantage. The gas evolution is completely avoided under these reaction conditions.

Da das Dihydropyran ein wichtiger Ausgangskörper zur Herstellung von Lösungs- und Weichmachungsmitteln u. dgl. ist, stellt das vorliegende verbesserte Darstellungsverfahren eine wertvolle Bereicherung der Technik dar.Since the dihydropyran is an important starting material for the production of Solvents, plasticizers, and the like, the present provides improved Representation process a valuable addition to technology.

Beispiel Durch einen Kontaktofen, der mit einem nach dem Verfahren der französischen Patentschrift 775 82r_ erhaltenen Aktiv-Tonerde-Kontakt beschickt ist, leitet man Tetrahydrofurfuralkohol in einer Menge von stündlich 0,5 kg je Liter Kontaktraum bei einer Temperatur von 28o bis 300°.Example Tetrahydrofurfural alcohol is passed in an hourly rate of 0.5 kg per liter of contact space at a temperature of 28o to 300 ° through a contact furnace charged with an active alumina contact obtained by the process of French patent 775 82r.

Das aus dem Kontaktofen austretende Reaktionsprodukt bildet nach dem Abkühlen zwei Schichten. Die obere, das Dihydropyran enthaltende Schicht wird abgehoben und. durch Wasserdampfdestillation und anschließende azeotropische Destillation aufgearbeitet. Man erhält hierbei Dihydropyran in einer Ausbeute von mindestens 85 The reaction product emerging from the contact furnace forms two layers after cooling. The upper layer containing the dihydropyran is lifted off and. worked up by steam distillation and subsequent azeotropic distillation. This gives dihydropyran in a yield of at least 85

Claims (1)

PATENTANSPRUCH: Verfahren zur Herstellung von Dihydropyran durch katalytische Dehydratisierung von Tetrahydrofurfuralkohol, dadurch gekennzeichnet, daß als Katalysator eine kolloidale Form von Aluminiumoxyd verwendet wird, wie sie gemäß dem Verfahren der französischen Patentschrift 775 821 erhalten wird.PATENT CLAIM: Process for the production of dihydropyran by catalytic Dehydration of tetrahydrofurfur alcohol, characterized in that as a catalyst a colloidal form of alumina is used as described in the procedure French patent 775,821 is obtained.
DEC2463D 1941-11-05 1941-11-05 Process for the production of dihydropyran Expired DE858564C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DEC2463D DE858564C (en) 1941-11-05 1941-11-05 Process for the production of dihydropyran

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEC2463D DE858564C (en) 1941-11-05 1941-11-05 Process for the production of dihydropyran

Publications (1)

Publication Number Publication Date
DE858564C true DE858564C (en) 1952-12-08

Family

ID=7012936

Family Applications (1)

Application Number Title Priority Date Filing Date
DEC2463D Expired DE858564C (en) 1941-11-05 1941-11-05 Process for the production of dihydropyran

Country Status (1)

Country Link
DE (1) DE858564C (en)

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