DE495334C - Process for the cleavage of A-ethylidene diacetate - Google Patents

Process for the cleavage of A-ethylidene diacetate

Info

Publication number
DE495334C
DE495334C DEV24275D DEV0024275D DE495334C DE 495334 C DE495334 C DE 495334C DE V24275 D DEV24275 D DE V24275D DE V0024275 D DEV0024275 D DE V0024275D DE 495334 C DE495334 C DE 495334C
Authority
DE
Germany
Prior art keywords
cleavage
ethylidene diacetate
acid
nitrobenzene
aldehyde
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
DEV24275D
Other languages
German (de)
Inventor
Dr Hans Walter
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.)
VER fur CHEMISCHE IND AKT GES
Original Assignee
VER fur CHEMISCHE IND AKT GES
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 VER fur CHEMISCHE IND AKT GES filed Critical VER fur CHEMISCHE IND AKT GES
Priority to DEV24275D priority Critical patent/DE495334C/en
Application granted granted Critical
Publication of DE495334C publication Critical patent/DE495334C/en
Expired legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/51—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition
    • C07C45/54—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition of compounds containing doubly bound oxygen atoms, e.g. esters
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/54—Preparation of carboxylic acid anhydrides
    • C07C51/56—Preparation of carboxylic acid anhydrides from organic acids, their salts, their esters or their halides, e.g. by carboxylation

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Description

Verfahren zur Spaltung von Äthylidendiacetat Es ist bereits bekannt, die Spaltung von 3thylidendiacetat in Aldehyd und Essigsäureanhydrid in Gegenwart indifferenter Verdünnungsmittel für die die Spaltung bewirkende Säure auszuführen, urn damit die Verharzung des Aldehyds hintanzuhalten. Die für diesen Zweck bisher vorgeschlagenen Verdünnungsmittel, wie z. B.. bestimmte Kohlenwasserstoffe, besitzen meist einen niedrigen. Siedepunkt und kommen meist nur als Lösungsmittel für einige wenige Säuren, wie z. B. Metaborsäure, in Betracht.Process for the cleavage of ethylidene diacetate It is already known the cleavage of 3-ethylidene diacetate into aldehyde and acetic anhydride in the presence to use an indifferent diluent for the acid causing the cleavage, In order to prevent the aldehyde from gumming up. The one for this purpose so far proposed diluents, such as. B. Certain hydrocarbons mostly a low one. Boiling point and mostly only come as a solvent for some a few acids, such as B. metaboric acid.

Es wurde gefunden, daß man die Spaltung ohne jede Verharzung in äußerst vorteilhafter Weise durchführen kann, wenn man als Verdünnungsmittel der katalytisch wirkenden Säure Nitrobenzol anwendet. Das Nitrflbenzol hat nicht- nur ein ausgezeichnetes Lösungsvermögen für sämtliche in Betracht kommenden starken Säuren, sondern besitzt auch einen hohen Siedepunkt, so daß man nach erfolgtem Abtrieb des Aldehyds auch das Anhydrid ohne weiteres herausdestillieren känn. Infolge des höheren Siedepunktes wird eine schädliche Konzentrationssteigerung der Säure vermieden, wobei die Verharzung bis zum Schluß der Reaktion verhütet und damit ein kontinuierliches Arbeiten erleichtert wird. Beispiel Eine Lösung von o,o5 g wasserfreier Schwefelsäure oder Benzolsulfonsäure in ioo g Nitrobenzol und 40 g Athylidendiacetat werden destilliert. Während ohne Zusatz von Nitrobenzol dieses Gemisch in kürzester Zeit völlig verharzen würde, bleibt im vorliegenden Fall das Reaktionsgemisch bis ans Ende der Reaktion völlig klar.It has been found that the cleavage can be carried out extremely without any resinification can be carried out advantageously if the catalytic diluent active acid nitrobenzene applies. Nitrflbenzene not only has an excellent one Solvent power for all possible strong acids, but has also has a high boiling point, so that after the aldehyde has been driven off, too the anhydride can easily distill out. As a result of the higher boiling point a harmful increase in the concentration of the acid is avoided, whereby the resinification Prevented until the end of the reaction and thus facilitates continuous work will. Example A solution of 0.05 g of anhydrous sulfuric acid or benzenesulfonic acid in 100 g of nitrobenzene and 40 g of ethylidene diacetate are distilled. While without The addition of nitrobenzene would completely resinify this mixture in a very short time, In the present case, the reaction mixture remains complete until the end of the reaction clear.

Man kann die Reaktion auch dadurch beschleunigen, daß man während der Destillation einen geeigneten Gasstrom hindurchleitet.The reaction can also be accelerated by during a suitable gas stream is passed through the distillation.

Man erhält im Destillat eine Menge von Acetaldehyd, die ungefähr 9o % der Theorie ausmacht. Als inerte Gase kommen in Betracht: Kohlensäure, Leuchtgas, Wasserstoff USW. An amount of acetaldehyde which makes up about 90% of theory is obtained in the distillate. The following inert gases can be considered: carbon dioxide, luminous gas, hydrogen, etc.

Der Grad der Beschleunigung hängt jedenfalls ganz von der Geschwindigkeit ab, mit der das inerte Gas durch die Spaltungsflüssigkeit durchgeleitet wird, da dasselbe lediglich nur den Zweck hat, das Spaltungsgleichgewicht zugunsten der Spaltung zu verschieben, indem es den gebildeten Aldehyd immer wieder wegführt.In any case, the degree of acceleration depends entirely on the speed from, with which the inert gas is passed through the fission liquid, there its only purpose is to balance the split in favor of split to move by repeatedly carrying away the aldehyde formed.

Claims (1)

PATENTANSPRUCfI: Verfahren zur Spaltung von Äthylidendiacetat in Acetaldehyd und Essigsäureanhydrid in .Gegenwart einer katalytisch wirkenden Säure, wie z. B. Schwefelsäure, und unter Anwendung eines indifferenten Verdünnungsmittels, dadurch gekennzeichnet, daß man Nitrobenzol als Verdünnungsmittel zur Anwendung bringt.PATENT CLAIM: Process for the cleavage of ethylidene diacetate into acetaldehyde and acetic anhydride in .Gegenwart a catalytically active acid, such as. B. Sulfuric acid, and using an inert diluent, thereby characterized in that nitrobenzene is used as a diluent.
DEV24275D 1928-08-23 1928-08-23 Process for the cleavage of A-ethylidene diacetate Expired DE495334C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DEV24275D DE495334C (en) 1928-08-23 1928-08-23 Process for the cleavage of A-ethylidene diacetate

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEV24275D DE495334C (en) 1928-08-23 1928-08-23 Process for the cleavage of A-ethylidene diacetate

Publications (1)

Publication Number Publication Date
DE495334C true DE495334C (en) 1930-04-15

Family

ID=7581080

Family Applications (1)

Application Number Title Priority Date Filing Date
DEV24275D Expired DE495334C (en) 1928-08-23 1928-08-23 Process for the cleavage of A-ethylidene diacetate

Country Status (1)

Country Link
DE (1) DE495334C (en)

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