AT58733B - Process for the preparation of isoprene from as-dimethylallene. - Google Patents

Process for the preparation of isoprene from as-dimethylallene.

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Publication number
AT58733B
AT58733B AT58733DA AT58733B AT 58733 B AT58733 B AT 58733B AT 58733D A AT58733D A AT 58733DA AT 58733 B AT58733 B AT 58733B
Authority
AT
Austria
Prior art keywords
isoprene
dimethylallene
preparation
vacuum
alumina
Prior art date
Application number
Other languages
German (de)
Original Assignee
Basf 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 Basf Ag filed Critical Basf Ag
Application granted granted Critical
Publication of AT58733B publication Critical patent/AT58733B/en

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  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)

Description

  

   <Desc/Clms Page number 1> 
 



  Verfahren zur Darstellung von Isopren aus as-Dimethylallen. 



   Leitet man as-Dimethylallen bei höherer Temperatur und, um die Bildung polymerer Kohlenwasserstoffe zu vermeiden, zweckmässig im Vakuum über geeignete Kontaktsubstanzen, so tritt, wie gefunden wurde, eine Verschiebung der Doppelbindungen im Molekül ein und es lagert sich das Demithylallen in das isomere Isopren   nm.   Als für diese Umlagerung besonders geeignet haben sich Tonerde verschiedenster Herkunft und tonerdehaltige Materialien erwiesen. 



    Beispiel :   
Ein mit Tonerde in Stücken beschicktes, auf etwa 3000 C heizbares Rohr ist einer-   seits     mit piner Zutropfvorrichtung,   andererseits mit durch   Kohlensäureäther   kühlbaren Vorlagen und durch diese mit einer Vakuumpumpe verbunden. Nach dem Evakuieren und Erhitzen lässt man Dimethylallen (Siedepunkt 39 bis   410 C)   zutropfen, dass ein Vakuum von 20 bis 30   111m bestehen   bleibt. In den Vorlagen kondensiert sich fast reines Isopren vom Siedepunkt 32 bis   340 C.   



   Analog kann man verfahren, wenn man statt des Vakuums von   20   bis 30 mm nur teilweise verminderten oder gewöhnlichen Druck anwendet, doch ist dies weniger vorteilhaft, indem leicht Zersetzung eintritt, die beim Arbeiten Im Vakuum nicht oder kaum erfolgt. 

**WARNUNG** Ende DESC Feld kannt Anfang CLMS uberlappen**.



   <Desc / Clms Page number 1>
 



  Process for the preparation of isoprene from as-dimethylallene.



   If as-dimethylallene is passed at a higher temperature and, in order to avoid the formation of polymeric hydrocarbons, expediently in a vacuum via suitable contact substances, a shift in the double bonds in the molecule occurs, as has been found, and the demithylallene is deposited in the isomeric isoprene nm Alumina of various origins and alumina-containing materials have proven to be particularly suitable for this rearrangement.



    Example:
A tube filled with alumina in pieces and heatable to about 3000 C is connected on the one hand to a pin dropping device, on the other hand to templates that can be cooled by carbonic acid ether and through this to a vacuum pump. After evacuation and heating, dimethylallene (boiling point 39 to 410 C) is added dropwise so that a vacuum of 20 to 30 111m remains. Almost pure isoprene with a boiling point of 32 to 340 C. condenses in the templates.



   An analogous procedure can be used if, instead of the vacuum of 20 to 30 mm, only partially reduced or normal pressure is used, but this is less advantageous as decomposition easily occurs, which does not or hardly takes place when working in a vacuum.

** WARNING ** End of DESC field may overlap beginning of CLMS **.

 

Claims (1)

PATENT ANSPRUCH : Verfahren zur Darstellung von Isopren aus o-I) imethy) aHen, dadurch gekennzeichnet, dass man letzteres bei höherer Temperatur und zweckmässig im Vakuum über Tonerde oder tonerdehaltige Materialien leitet. **WARNUNG** Ende CLMS Feld Kannt Anfang DESC uberlappen**. PATENT CLAIM: Process for the preparation of isoprene from o-I) imethy) aHen, characterized in that the latter is passed over alumina or alumina-containing materials at a higher temperature and advantageously in a vacuum. ** WARNING ** End of CLMS field may overlap beginning of DESC **.
AT58733D 1911-05-12 1912-02-12 Process for the preparation of isoprene from as-dimethylallene. AT58733B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE58733X 1911-05-12

Publications (1)

Publication Number Publication Date
AT58733B true AT58733B (en) 1913-04-25

Family

ID=5629692

Family Applications (2)

Application Number Title Priority Date Filing Date
AT58733D AT58733B (en) 1911-05-12 1912-02-12 Process for the preparation of isoprene from as-dimethylallene.
AT62970D AT62970B (en) 1911-05-12 1913-01-13 Process for the preparation of isoprene.

Family Applications After (1)

Application Number Title Priority Date Filing Date
AT62970D AT62970B (en) 1911-05-12 1913-01-13 Process for the preparation of isoprene.

Country Status (1)

Country Link
AT (2) AT58733B (en)

Also Published As

Publication number Publication date
AT62970B (en) 1914-01-10

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