DE943705C - Process for the production of styrenes - Google Patents
Process for the production of styrenesInfo
- Publication number
- DE943705C DE943705C DEB23900A DEB0023900A DE943705C DE 943705 C DE943705 C DE 943705C DE B23900 A DEB23900 A DE B23900A DE B0023900 A DEB0023900 A DE B0023900A DE 943705 C DE943705 C DE 943705C
- Authority
- DE
- Germany
- Prior art keywords
- styrenes
- hydroperoxides
- production
- carbinols
- acidic medium
- 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
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C15/00—Cyclic hydrocarbons containing only six-membered aromatic rings as cyclic parts
- C07C15/40—Cyclic hydrocarbons containing only six-membered aromatic rings as cyclic parts substituted by unsaturated carbon radicals
- C07C15/42—Cyclic hydrocarbons containing only six-membered aromatic rings as cyclic parts substituted by unsaturated carbon radicals monocyclic
- C07C15/44—Cyclic hydrocarbons containing only six-membered aromatic rings as cyclic parts substituted by unsaturated carbon radicals monocyclic the hydrocarbon substituent containing a carbon-to-carbon double bond
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
Verfahren zur Herstellung von Styrolen Gegenstand der Erfindung ist ein Verfahren zur Herstellung von Styrolen aus alkylsubstituierten aromatischen Verbindungen von der Strukturformel in der Rt und R2 Alkylgruppen und Ar eine Aryl-oder substituierte Arylgruppe darstellen, das darin besteht, daß man zunächst, z. B. nach dem Verfahren der Patentanmeldung B I85I6 IVC/I20, deren Hydroperoxyde herstellt, diese zu den Carbinolen reduziert und anschließend oder gleichzeitig Wasser abspaltet. Die dem tertiären C-Atom benachbarten Benzol- oder Naphthalinringe, heterocyclischen oder hydroaromatischen Ringe üben dabei eine aktivierende Wirkung aus, so daß sich die - Hydroperoxyde leicht reduzieren lassen, z. B. mit naszierendem Wasserstoff, wie er ja im sauren Medium mit Metallen, z. B. Zink und Eisen, oder im alkalischen Medium mit Aluminium und Natrinmamalgam entsteht oder unter Einfluß des Wasserstoffes, der bei einer Elektrolyse auftritt.Process for the Production of Styrenes The invention relates to a process for the production of styrenes from alkyl-substituted aromatic compounds of the structural formula in which Rt and R2 represent alkyl groups and Ar represents an aryl or substituted aryl group, which consists in first, e.g. B. by the method of patent application B I85I6 IVC / I20, which produces hydroperoxides, reduces them to the carbinols and then or at the same time splits off water. The benzene or naphthalene rings, heterocyclic or hydroaromatic rings adjacent to the tertiary carbon atom exert an activating effect so that the - hydroperoxides can be easily reduced, e.g. B. with nascent hydrogen, as it does in an acidic medium with metals such. B. zinc and iron, or in an alkaline medium with aluminum and sodium mamalgam or under the influence of the hydrogen that occurs during electrolysis.
Aus den Hydroperoxyden entstehen dadurch Carbinole. Darüber hinaus spalten, wie gefunden wurde, Hydroperoxyde bei erhöhter Temperatur in saurem Medium bereits Sauerstoff ab und bilden dadurch ebenfalls Carbinole. Aus ihnen erhält man durch Wasserabspaltung die entsprechenden Styrole.This creates carbinols from the hydroperoxides. Furthermore It was found that hydroperoxides split into sour The medium already absorbs oxygen and thereby also forms carbinols. Receives from them the corresponding styrenes are obtained by splitting off water.
Die Wasserabspaltung kann man in einfacher Weise durch Erwärmen der Carbinole mit verdünnten Säuren erreichen. The elimination of water can be done in a simple manner by heating the Achieve carbinols with dilute acids.
Das neue Verfahren gestattet also, aus alkylierten aromatischen oder hydroaromatischen Verbindungen mit tertiären CH-Gruppen ohne nennenswerte Bildung von Nebenprodukten mit guten Ausbeuten bei milden Versuchsbedingungen die entsprechenden Styrole zu erhalten. The new process thus allows, from alkylated aromatic or hydroaromatic compounds with tertiary CH groups without significant formation of by-products with good yields under mild test conditions the corresponding To obtain styrenes.
Beispiele I. Isopropylbenzol wird mit Luftsauerstoff oder reinem Sauerstoff oder nach dem Verfahren der Patentanmeldung B I85I6 IVC/I20 in Cumolhydroperoxyd mit naszierendem Wasserstoff behandelt, indem z. B. die 50°/oigeLösung von Cumolhydroperoxyd mit Schwefelsäure angesäuert wird und Zink-Granalien zugegeben werden. Das Cumolhydroperoxyd wird auf diese Weise zu Dimethylphenylcarbinol reduziert. Durch Kochen des Dimethylphenylcarbinols mit Säure spaltet sich Wasser ab, und es bildet sich a-Methylstyrol. Examples I. Isopropylbenzene is made with atmospheric oxygen or pure Oxygen or in cumene hydroperoxide according to the method of patent application B18516 IVC / I20 treated with nascent hydrogen by e.g. B. the 50% solution of cumene hydroperoxide is acidified with sulfuric acid and zinc granules are added. The cumene hydroperoxide is reduced in this way to dimethylphenylcarbinol. By boiling the dimethylphenylcarbinol water is split off with acid and α-methylstyrene is formed.
2. Isopropylbenzol wird mit ozonisiertem Sauerstoff unter Druck in schwach saurem Medium bei PH kleiner als 7 behandelt. Dabei entsteht intermediär Isopropylbenzolhydroperoxyd, das in dem vorhandenen saurem Medium unter Abspaltung von Sauerstoff in das Carbinol übergeht. Letzteres wird, ohne es zu isolieren, mit 10 0/o Schwefelsäure bei IloO gekocht. Darauf wird zuerst Wasser und nicht umgesetztes Cumol abdestilliert. Der Rückstand, der das a-Methylstyrol enthält, wird unter Vakuum destilliert. 2. Isopropylbenzene is pressurized in with ozonated oxygen treated with weakly acidic medium at pH less than 7. This creates an intermediate Isopropylbenzene hydroperoxide, which splits off in the existing acidic medium of oxygen passes into the carbinol. The latter is done with without isolating it 10 0 / o sulfuric acid boiled at IloO. Then water is added first and unreacted Cumene distilled off. The residue, which contains the α-methylstyrene, is removed under vacuum distilled.
Die Ausbeuten an a-Methylstyrol betragen in den Beispielen I und 2 etwa go bis 95 O/o. The yields of α-methylstyrene are in Examples I and 2 to about 95%.
Man kann natürlich auch die Hydroperoxyde isolieren und dann die Peroxyde im Sinne des Verfahrens gemäR der Erfindung in die entsprechenden Styrole überführen. You can of course also isolate the hydroperoxides and then the Peroxides in the context of the process according to the invention into the corresponding styrenes convict.
PATENTANSPROCHE: I. Verfahren zur Herstellung von Styrolen aus alkylsubstituierten aromatischen Verbindungen von der Strukturformel in der Rt und R2 Alkylgruppen und Ar eine Aryl- oder substituierte Arylgruppe darstellen, dadurch gekennzeichnet, daß man zunächst, z. B. nach dem Verfahren der Patentanmeldung B I85I6 i6 IVc/ I2 O, deren Hydroperoxyde herstellt, diese zu den Carbinolen reduziert und anschließend oder gleichzeitig Wasser abspaltet.PATENT CLAIM: I. Process for the preparation of styrenes from alkyl-substituted aromatic compounds of the structural formula in which Rt and R2 represent alkyl groups and Ar an aryl or substituted aryl group, characterized in that first, for. B. by the method of patent application B I85I6 i6 IVc / I2 O, which produces hydroperoxides, reduces them to the carbinols and then or at the same time splits off water.
Claims (1)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEB23900A DE943705C (en) | 1953-01-23 | 1953-01-23 | Process for the production of styrenes |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEB23900A DE943705C (en) | 1953-01-23 | 1953-01-23 | Process for the production of styrenes |
Publications (1)
Publication Number | Publication Date |
---|---|
DE943705C true DE943705C (en) | 1956-06-01 |
Family
ID=6961317
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DEB23900A Expired DE943705C (en) | 1953-01-23 | 1953-01-23 | Process for the production of styrenes |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE943705C (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1025864B (en) * | 1954-07-13 | 1958-03-13 | Rhone Poulenc Sa | Process for the dehydration of dimethylphenylcarbinol |
DE1138758B (en) * | 1958-03-03 | 1962-10-31 | Inst Francais Du Petrol | Process for the preparation of conjugated diolefins |
DE1186047B (en) * | 1959-07-13 | 1965-01-28 | Phenolchemie Ges Mit Beschraen | Process for the preparation of alkyl-substituted styrenes |
-
1953
- 1953-01-23 DE DEB23900A patent/DE943705C/en not_active Expired
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1025864B (en) * | 1954-07-13 | 1958-03-13 | Rhone Poulenc Sa | Process for the dehydration of dimethylphenylcarbinol |
DE1138758B (en) * | 1958-03-03 | 1962-10-31 | Inst Francais Du Petrol | Process for the preparation of conjugated diolefins |
DE1186047B (en) * | 1959-07-13 | 1965-01-28 | Phenolchemie Ges Mit Beschraen | Process for the preparation of alkyl-substituted styrenes |
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