EP0072914B1 - Process for the production of alkyl-substituted benzaldehydes - Google Patents

Process for the production of alkyl-substituted benzaldehydes Download PDF

Info

Publication number
EP0072914B1
EP0072914B1 EP82106344A EP82106344A EP0072914B1 EP 0072914 B1 EP0072914 B1 EP 0072914B1 EP 82106344 A EP82106344 A EP 82106344A EP 82106344 A EP82106344 A EP 82106344A EP 0072914 B1 EP0072914 B1 EP 0072914B1
Authority
EP
European Patent Office
Prior art keywords
alkyl
oxide
hydrogen
substituted benzaldehydes
production
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
EP82106344A
Other languages
German (de)
French (fr)
Other versions
EP0072914A1 (en
Inventor
Dieter Dr. Degner
Hans Dr. Roos
Heinz Hannebaum
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.)
BASF SE
Original Assignee
BASF SE
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 SE filed Critical BASF SE
Publication of EP0072914A1 publication Critical patent/EP0072914A1/en
Application granted granted Critical
Publication of EP0072914B1 publication Critical patent/EP0072914B1/en
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B3/00—Electrolytic production of organic compounds
    • C25B3/20—Processes
    • C25B3/23—Oxidation

Definitions

  • the present invention relates to a process for the electrochemical production of alkyl-substituted benzaldehydes.
  • DE-OS 2 855 508 describes a process in which the electrooxidation of the alkylbenzenes in water and alkanoic acids is carried out.
  • the alkyl-substituted benzaldehydes are obtained in good yields.
  • the disadvantage of this method is the decrease in the current yields at very high conversions.
  • the graphite anodes show a graphite removal in the long-term test.
  • the object was therefore to find a process which makes it possible to obtain the benzaldehydes in the electrooxidation of alkylbenzenes for the preparation of the corresponding benzaldehydes, even at high conversions, in good current yields and with improved electrode stability.
  • graphite anodes which are treated with metal oxides such as ruthenium oxide, titanium dioxide, iron oxide, chromium oxide, cobalt oxide, manganese dioxide, nickel oxide or with carbides such as Tungsten carbide, are coated.
  • metal oxides such as ruthenium oxide, titanium dioxide, iron oxide, chromium oxide, cobalt oxide, manganese dioxide, nickel oxide or with carbides such as Tungsten carbide.
  • Mixtures of the coating materials mentioned can also be used, such as a mixture of iron oxide and cobalt oxide.
  • alkyl radicals R 'and R 2 in the starting materials of formula II are, for. B. those with 1 to 6, preferably 1 to 4 carbon atoms.
  • Phenyl radicals which can be substituted by alkyl, halogen, alkoxy and / or acyloxy groups may be mentioned as aryl radicals R.
  • Starting materials of formula II are thus methylbenzenes, benzyl alcohols or the alkanoic acid esters of benzyl alcohols which are not substituted or contain the radical R 'mentioned, such as toluene, p-xylene, p-tert-butyltoluene, p-phenyltoluene, benzyl alcohol, p-methylbenzyl alcohol , p-tert-butylbenzyl alcohol, benzyl acetate, p-methylbenzyl acetate and p-tert-butylbenzyl acetate.
  • R 'mentioned such as toluene, p-xylene, p-tert-butyltoluene, p-phenyltoluene, benzyl alcohol, p-methylbenzyl alcohol , p-tert-butylbenzyl alcohol, benzyl acetate, p-methylbenz
  • Formic acid acetic acid and propionic acid are preferred as alkanoic acids.
  • a mixture of the benzene derivative of the formula II, water and the alkanoic acid is used as the electrolyte, which may additionally contain a conductive salt to improve the conductivity.
  • the usual salts in organic electrochemistry can be used as the conductive salts, which are soluble in the solution to be electrolyzed and largely stable under the test conditions.
  • Examples of conductive salts are tetrafluorobarates, fluorides, hexafluorophosphates, sulfates or sulfonates. The method is preferably carried out in undivided cells.
  • the alkylbenzene compound of the formula II is preferably converted to over 80%.
  • the current density in the method is, for. B. between 1 and 15 A / dm 2.
  • the electrolysis can be carried out batchwise as well as be carried out continuously.
  • the electrolysis discharges are preferably worked up by distillation.
  • the electrolyte from water-alkanoic acid conducting salt is expediently returned to the electrolysis.
  • the graphite anodes to be used according to the invention may e.g. B. by coating the electrode base with the help of thermal spraying or by thermal decomposition of suitable compounds.
  • the oxides or carbides are fed directly in powder form to a spraying system, preferably a plasma spraying system, and are applied to the graphite body with the aid thereof.
  • the compound is applied to the graphite body in dissolved form and the active layer is produced by baking at elevated temperature.
  • So z. B. a titanium oxide layer by spraying or brushing the electrode with butyl titanate in butanol and then heating to 500 to 600 ° C.
  • the coated anodes mentioned surprisingly result in an improvement in the selectivity and an increase in the current yields even at high conversions. This considerably simplifies the processing of the electrolysis discharges. Furthermore, the coated graphite electrodes allow longer running times due to the lower removal.
  • the process according to the invention is intended to be based on the electrosynthesis of 4-tert. Butylbenzaldehyde are explained in more detail.
  • the electrolyte is pumped through a heat exchanger during the electrolysis. After the electrolysis has ended, water and acetic acid are distilled off at atmospheric pressure, NaBF 4 is filtered off and the crude 4-tert. Butylbenzaldehyde (TBA) pure distilled at 2 to 20 torr and 40 to 125 ° C.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Electrodes For Compound Or Non-Metal Manufacture (AREA)

Description

Die vorliegende Erfindung betrifft ein Verfahren zur elektrochemischen Herstellung von alkylsubstituierten Benzaldehyden.The present invention relates to a process for the electrochemical production of alkyl-substituted benzaldehydes.

Die Elektrosynthese von alkylsubstituierten Benzaldehyden durch anodische Oxidation der entsprechenden Alkylbenzole ist aus Helv. Chem. Acta 9,1097 (1926) bekannt. Bei diesem Verfahren, bei dem die Elektrooxidation in schwefelsaurer Lösung durchgeführt wird, werden die Aldehyde nur in sehr geringer Selektivität gebildet. In der US-PS 4148 696 wird ein Verfahren beschrieben, bei dem man die Elektrooxidation mit einem Elektrolyten durchführt, der neben dem Alkylbenzol Wasser, Methylenchlorid, Propionsäure und Natriumpropionat sowie als Phasentransferreagentien quartäre Ammoniumsalze enthält. Auch bei diesem Verfahren entstehen die Aldehyde nur in geringen Ausbeuten. Die Aufarbeitung der Elektrolyseausträge und die Rückführung des Elektrolyten sind so aufwendig, daß sie einer Durchführung dieser Synthese in der Technik im Wege stehen. In der DE-OS 2 855 508 wird ein Verfahren beschrieben, bei dem man die Elektrooxidation der Alkylbenzole in Wasser und Alkansäuren vornimmt. Hierbei werden die alkylsubstituierten Benzaldehyde in guten Ausbeuten erhalten. Nachteilig bei diesem Verfahren ist jedoch die Abnahme der Stromausbeuten bei sehr hohen Umsätzen. Weiterhin weisen die Graphitanoden im Langzeitversuch einen Graphitabtrag auf.The electrosynthesis of alkyl-substituted benzaldehydes by anodic oxidation of the corresponding alkylbenzenes is known from Helv. Chem. Acta 9, 1097 (1926). In this process, in which the electrooxidation is carried out in sulfuric acid solution, the aldehydes are formed with very little selectivity. US Pat. No. 4,148,696 describes a process in which the electrooxidation is carried out using an electrolyte which, in addition to the alkylbenzene, contains water, methylene chloride, propionic acid and sodium propionate and also quaternary ammonium salts as phase transfer reagents. In this process, too, the aldehydes are formed only in low yields. The processing of the electrolysis discharges and the recycling of the electrolyte are so complex that they stand in the way of carrying out this synthesis in technology. DE-OS 2 855 508 describes a process in which the electrooxidation of the alkylbenzenes in water and alkanoic acids is carried out. The alkyl-substituted benzaldehydes are obtained in good yields. However, the disadvantage of this method is the decrease in the current yields at very high conversions. Furthermore, the graphite anodes show a graphite removal in the long-term test.

Es bestand daher die Aufgabe, ein Verfahren zu finden, das es gestattet, bei der Elektrooxidation von Alkylbenzolen zur Herstellung der entsprechenden Benzaldehyde die Benzaldehyde auch bei hohen Umsätzen in guten Stromausbeuten und bei einer verbesserten Elektrodenstabilität zu erhalten.The object was therefore to find a process which makes it possible to obtain the benzaldehydes in the electrooxidation of alkylbenzenes for the preparation of the corresponding benzaldehydes, even at high conversions, in good current yields and with improved electrode stability.

Es wurde nun gefunden, daß man bei der Herstellung von alkylsubstituierten Benzaldehyden der allgemeinen Formel

Figure imgb0001
in der Rl ein Wasserstoffatom, einen Alkylrest oder Arylrest bedeutet, durch Elektrooxidation von Alkylbenzolderivaten der allgemeinen Formel
Figure imgb0002
in der X für ein Wasserstoffatom, eine Hydroxylgruppe oder eine R2COO-Gruppe steht und R2 ein Wasserstoffatom oder eine Alkylgruppe bedeutet, in Wasser oder einer Alkansäure die gewünschten Ergebnisse erhält, wenn man Graphitanoden verwendet, die mit Metalloxiden oder Carbiden beschichtet sind.It has now been found that in the preparation of alkyl-substituted benzaldehydes of the general formula
Figure imgb0001
 in which R 1 represents a hydrogen atom, an alkyl radical or an aryl radical, by electrooxidation of alkylbenzene derivatives of the general formula
Figure imgb0002
 in which X represents a hydrogen atom, a hydroxyl group or an R 2 COO group and R 2 represents a hydrogen atom or an alkyl group, in water or an alkanoic acid the desired results are obtained if graphite anodes are coated which are coated with metal oxides or carbides.

Nach dem neuen Verfahren, bei dem man die Benzaldehyde der Formel bei hohen Umsätzen in hohen Material- und Stromausbeuten erhält, verwendet man Graphitanoden, die mit Metalloxiden, wie Rutheniumoxid, Titandioxid, Eisenoxid, Chromoxid, Kobaltoxid, Mangandioxid, Nickeloxid oder mit Carbiden, wie Wolframcarbid, beschichtet sind. Man kann auch Mischungen der genannten Beschichtungsmaterialien verwenden, wie ein Gemisch aus Eisenoxid und Kobaltoxid.According to the new process, in which the benzaldehydes of the formula are obtained at high conversions in high material and current yields, graphite anodes are used which are treated with metal oxides such as ruthenium oxide, titanium dioxide, iron oxide, chromium oxide, cobalt oxide, manganese dioxide, nickel oxide or with carbides such as Tungsten carbide, are coated. Mixtures of the coating materials mentioned can also be used, such as a mixture of iron oxide and cobalt oxide.

Die Alkylreste R' und R2 in den Ausgangsstoffen der Formel II sind z. B. solche mit 1 bis 6, vorzugsweise 1 bis 4 C-Atomen. Als Arylreste R seien Phenylreste, die durch Alkyl-, Halogen-, Alkoxy- und/oder Acyloxygruppen substituiert sein können, genannt. Ausgangsstoffe der Formel II sind somit Methylbenzole, Benzylalkohole oder die Alkansäureester der Benzylalkohole, die nicht substituiert sind oder den genannten Rest R' enthalten, wie Toluol, p-Xylol, p-tert.-Butyltoluol, p-Phenyltoluol, Benzylalkohol, p-Methylbenzylalkohol, p-tert.-Butylbenzylalkohol, Benzylacetat, p-Methylbenzylacetat und p-tert.-Butylbenzylacetat. Von diesen Ausgangsstoffen sind p-Xylol, p-tert.-Butyltoluol, p-Methylbenzylalkohol, p-tert.-Butylbenzylalkohol, p-Methylbenzylacetat und p-tert.-Butylbenzylacetat von besonderem technischem Interesse.The alkyl radicals R 'and R 2 in the starting materials of formula II are, for. B. those with 1 to 6, preferably 1 to 4 carbon atoms. Phenyl radicals which can be substituted by alkyl, halogen, alkoxy and / or acyloxy groups may be mentioned as aryl radicals R. Starting materials of formula II are thus methylbenzenes, benzyl alcohols or the alkanoic acid esters of benzyl alcohols which are not substituted or contain the radical R 'mentioned, such as toluene, p-xylene, p-tert-butyltoluene, p-phenyltoluene, benzyl alcohol, p-methylbenzyl alcohol , p-tert-butylbenzyl alcohol, benzyl acetate, p-methylbenzyl acetate and p-tert-butylbenzyl acetate. Of these starting materials, p-xylene, p-tert-butyltoluene, p-methylbenzyl alcohol, p-tert-butylbenzyl alcohol, p-methylbenzyl acetate and p-tert.-butylbenzyl acetate are of particular technical interest.

Als Alkansäuren sind Ameisensäure, Essigsäure und Propionsäure bevorzugt.Formic acid, acetic acid and propionic acid are preferred as alkanoic acids.

Als Elektrolyt wird ein Gemisch aus dem Benzolderivat der Formel II, Wasser und der Alkansäure verwendet, das zur Verbesserung der Leitfähigkeit zusätzlich ein Leitsalz enthalten kann. Als Leitsalze können dabei die in der organischen Elektrochemie üblichen Salze eingesetzt werden, die in der zu elektrolysierenden Lösung löslich und unter den Versuchsbedingungen weitgehend stabil sind. Beispiele für Leitsalze sind Tetrafluorobarate, Fluoride, Hexafluorophosphate, Sulfate oder Sulfonate. Das Verfahren wird bevorzugt in ungeteilten Zellen durchgeführt.A mixture of the benzene derivative of the formula II, water and the alkanoic acid is used as the electrolyte, which may additionally contain a conductive salt to improve the conductivity. The usual salts in organic electrochemistry can be used as the conductive salts, which are soluble in the solution to be electrolyzed and largely stable under the test conditions. Examples of conductive salts are tetrafluorobarates, fluorides, hexafluorophosphates, sulfates or sulfonates. The method is preferably carried out in undivided cells.

Als Kathoden werden beispielsweise Graphit-, Eisen-, Stahl-, Blei- oder Edelmetallelektroden eingesetzt. Die Alkylbenzolverbindung der Formel II wird bevorzugt zu über 80 %umgesetzt. Die Stromdichte beträgt bei dem Verfahren z. B. zwischen 1 und 15 A/dm2. Die Elektrolyse kann sowohl diskontinuierlich als auch kontinuierlich durchgeführt werden. DieAufarbeitung der Elektrolyseausträge erfolgt vorzugsweise destillativ. Der Elektrolyt aus Wasser-Alkansäure-Leitsalz wird zweckmäßigerweise zur Elektrolyse zurückgeführt.For example, graphite, iron, steel, lead or precious metal electrodes are used as cathodes. The alkylbenzene compound of the formula II is preferably converted to over 80%. The current density in the method is, for. B. between 1 and 15 A / dm 2. The electrolysis can be carried out batchwise as well as be carried out continuously. The electrolysis discharges are preferably worked up by distillation. The electrolyte from water-alkanoic acid conducting salt is expediently returned to the electrolysis.

Die erfindungsgemäß zu verwendenden Graphitanoden können z. B. durch Beschichtung der Elektrodengrundkörper mit Hilfe der thermischen Spritztechnik oder auch durch thermische Zersetzung geeigneter Verbindungen angefertigt werden. Im ersten Fall werden die Oxide oder Carbide direkt in Pulverform einer Spritzanlage, bevorzugt einer Plasmaspritzanlage, zugeführt und mit deren Hilfe auf den Graphitkörper aufgebracht. Im zweiten Fall wird die Verbindung in gelöster Form auf den Graphitkörper aufgebracht und durch Einbrennen bei erhöhter Temperatur die Aktivschicht erzeugt. So wird z. B. eine Titanoxid-Schicht durch Besprühen oder Einpinseln der Elektrode mit Butyltitanat in Butanol und anschließendes Erhitzen auf 500 bis 600°C erzeugt.The graphite anodes to be used according to the invention may e.g. B. by coating the electrode base with the help of thermal spraying or by thermal decomposition of suitable compounds. In the first case, the oxides or carbides are fed directly in powder form to a spraying system, preferably a plasma spraying system, and are applied to the graphite body with the aid thereof. In the second case, the compound is applied to the graphite body in dissolved form and the active layer is produced by baking at elevated temperature. So z. B. a titanium oxide layer by spraying or brushing the electrode with butyl titanate in butanol and then heating to 500 to 600 ° C.

Die genannten beschichteten Anoden ergeben beim Verfahren der Erfindung überraschenderweise eine Verbesserung der Selektivität sowie eine Erhöhung der Stromausbeuten auch bei hohen Umsätzen. Hierdurch vereinfacht sich die Aufarbeitung der Elektrolyseausträge wesentlich. Weiterhin lassen sich mit den beschichteten Graphitelektroden längere Laufzeiten infolge des geringeren Abtrags erreichen.In the process of the invention, the coated anodes mentioned surprisingly result in an improvement in the selectivity and an increase in the current yields even at high conversions. This considerably simplifies the processing of the electrolysis discharges. Furthermore, the coated graphite electrodes allow longer running times due to the lower removal.

Das erfindungsgemäße Verfahren soll im folgenden an der Elektrosynthese von 4-tert. Butylbenzaldehyd näher erläutert werden.The process according to the invention is intended to be based on the electrosynthesis of 4-tert. Butylbenzaldehyde are explained in more detail.

Reaktionsverlauf:Reaction process:

Figure imgb0003
Figure imgb0003
Figure imgb0004
Figure imgb0004

Der Elektrolyt wird während der Elektrolyse über einen Wärmetauscher gepumpt. Nach Beendigung der Elektrolyse wird Wasser und Essigsäure bei Normaldruck abdestilliert, NaBF4 abfiltriert und der rohe 4-tert. Butylbenzaldehyd (TBA) bei 2 bis 20 Torr und 40 bis 125°C reindestilliert.The electrolyte is pumped through a heat exchanger during the electrolysis. After the electrolysis has ended, water and acetic acid are distilled off at atmospheric pressure, NaBF 4 is filtered off and the crude 4-tert. Butylbenzaldehyde (TBA) pure distilled at 2 to 20 torr and 40 to 125 ° C.

Die Versuchsergebnisse sind in nachfolgender Tabelle zusammengestellt:

Figure imgb0005
Figure imgb0006
 The test results are summarized in the following table:
Figure imgb0005
Figure imgb0006

Claims (2)

1. A process for the preparation of alkyl-substituted benzaldehydes of the general formula
Figure imgb0009
where R1 is hydrogen, alkyl or aryl, by electrooxidation of alkylbenzene derivatives of the general formula
Figure imgb0010
where X is hydrogen, hydroxyl or R2COO-, R2 being hydrogen or alkyl, in water or an alkanoic acid, wherein graphite anodes coated with metal oxides or with carbides are used.
2. A process as claimed in claim 1, wherein graphite anodes coated with ruthenium oxide, titanium dioxide, iron oxide, chromium oxide, cobalt oxide, manganese dioxide, nickel oxide or tungsten carbide are used.
EP82106344A 1981-08-19 1982-07-15 Process for the production of alkyl-substituted benzaldehydes Expired EP0072914B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3132726 1981-08-19
DE19813132726 DE3132726A1 (en) 1981-08-19 1981-08-19 PROCESS FOR PRODUCING ALKYL-SUBSTITUTED BENZALDEHYDES

Publications (2)

Publication Number Publication Date
EP0072914A1 EP0072914A1 (en) 1983-03-02
EP0072914B1 true EP0072914B1 (en) 1984-10-31

Family

ID=6139614

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82106344A Expired EP0072914B1 (en) 1981-08-19 1982-07-15 Process for the production of alkyl-substituted benzaldehydes

Country Status (4)

Country Link
US (1) US4411746A (en)
EP (1) EP0072914B1 (en)
JP (1) JPS5845387A (en)
DE (2) DE3132726A1 (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58502027A (en) * 1981-11-23 1983-11-24 バロ−ス・コ−ポレ−ション Peripherals adapted to monitor low data rate serial input/output interfaces
US4643807A (en) * 1985-12-13 1987-02-17 The Dow Chemical Company Process for electrochemically forming an aromatic compound containing one or more alpha-acyloxylated aliphatic substitutent(s)
AU6672286A (en) * 1986-01-06 1987-07-09 Dow Chemical Company, The Electrocatalytic method for producing quinone methides and dihydroxybenzophenones
US4808494A (en) * 1986-03-12 1989-02-28 Combustion Engineering, Inc. Thermally actuated hydrogen secondary battery
NL8601826A (en) * 1986-07-12 1988-02-01 Stamicarbon METHOD FOR THE ELECTROCHEMICAL OXIDATION OF ORGANIC PRODUCTS.
US4871430A (en) * 1987-02-19 1989-10-03 The Dow Chemical Company Novel multifunctional compounds and electrolytic oxidative coupling process
IT1221775B (en) * 1988-01-08 1990-07-12 Giuseppe Bianchi SYNTHESIS PROCESS OF ORGANIC SUBSTANCES BY INDIRECT ELECTROCHEMISTRY WITH SOLID STATE REDOX SYSTEM
DE3913166A1 (en) * 1989-04-21 1990-10-25 Basf Ag METHOD FOR PRODUCING BENZALDEHYDDIALKYLACETALS AND NEW BENZALDEHYDDIALKYLACETALS AND BENZYL ESTERS
ATE113582T1 (en) * 1991-09-19 1994-11-15 Hoechst Ag PROCESS FOR THE OXIDATION OF HYDROXYMETHYLPYRIDINE DERIVATIVES TO PYRIDINECARBONIC ACID DERIVATIVES.
US10156842B2 (en) 2015-12-31 2018-12-18 General Electric Company Device enrollment in a cloud service using an authenticated application

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3775284A (en) * 1970-03-23 1973-11-27 J Bennett Non-passivating barrier layer electrodes
BE819674A (en) * 1973-09-13 1975-03-10 ANODES FOR ELECTROLYTIC PROCESSES
DE2600631A1 (en) * 1976-01-09 1977-07-14 Bitzer Diethelm Wear resistant coatings of carbide and/or nitride - obtd. by thermal decomposition of soln. contg. polyacrylamide and metal salt
US4148696A (en) * 1978-03-20 1979-04-10 Uop Inc. Electrochemical oxidation of activated alkyl aromatic compounds
WO1979000840A1 (en) * 1978-03-28 1979-10-18 Diamond Shamrock Techn Electrodes for electrolytic processes,especially metal electrowinning
DE2855508A1 (en) * 1978-12-22 1980-07-10 Basf Ag METHOD FOR PRODUCING BENZALDEHYDES

Also Published As

Publication number Publication date
EP0072914A1 (en) 1983-03-02
DE3261133D1 (en) 1984-12-06
US4411746A (en) 1983-10-25
JPS5845387A (en) 1983-03-16
DE3132726A1 (en) 1983-03-03

Similar Documents

Publication Publication Date Title
EP0011712B1 (en) Preparation of benzaldehyde dialkyl acetals substituted in the 4-position
DE2343054B1 (en) Process for the electrochemical production of pinacols
EP0072914B1 (en) Process for the production of alkyl-substituted benzaldehydes
EP0012942B1 (en) Electrolytic process for producing benzaldehydes
EP0129795B1 (en) Process for manufacturing benzaldehyde dialkylacetals
EP0902846B1 (en) Process for preparing phthalides
EP0638665B1 (en) Process for the preparation of benzaldehyde dialkyl acetals
EP0029995B1 (en) Process for the preparation of 4-tert.-butylbenzaldehyde
EP0179289B1 (en) Method for producing aromatic carboxylic esters
EP0502372B1 (en) 4-tert-Alkyl-2-Methylbenzaldehydedialkylacetals
EP0393668B1 (en) Method of preparation of benzaldehyde dialkyl acetals and new benzaldehyde dialkyl acetals
EP0152801B1 (en) Process for manufacturing benzaldehyde dialkylacetals
EP0347690B1 (en) Process for manufacturing benzene derivatives, and benzene derivatives
EP0030588B1 (en) Process for the preparation of p-tert.-butylbenzaldehyde
EP0237769B1 (en) Benzaldehyde-dialkyl acetals
EP0167097B1 (en) Process for preparing chloroolefins
DE3028757A1 (en) METHOD FOR PRODUCING P-TERT.-BUTYLBENZALDEHYDE
EP0554564A1 (en) Process for preparing benzaldehyde acetals
EP0179377B1 (en) Process for the preparation of 1-alkoxyisochromanes, and 1-alkoxy alkylisochromanes
DE10207238B4 (en) Process for electro-organic synthesis on carbon electrodes
DE2409117A1 (en) METHOD FOR THE PRODUCTION OF PROPIOLIC ACID
EP0384315B1 (en) Process for manufacturing lactones
DE2345461C3 (en) Process for the production of pinacol by the electrolytic hydrodimerization of acetone
CH651285A5 (en) CYCLOHEXADIENE DERIVATIVES AND METHOD FOR THE PRODUCTION THEREOF.
DE4116147A1 (en) METHOD FOR PRODUCING 1-ALKOXYISOCHROMANS

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19821211

AK Designated contracting states

Designated state(s): BE CH DE FR GB IT LI NL

ITF It: translation for a ep patent filed

Owner name: ING. C. GREGORJ S.P.A.

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): BE CH DE FR GB IT LI NL

REF Corresponds to:

Ref document number: 3261133

Country of ref document: DE

Date of ref document: 19841206

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19990618

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19990629

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19990630

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19990701

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19990716

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19990722

Year of fee payment: 18

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF THE APPLICANT RENOUNCES

Effective date: 20000714

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000715

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000731

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000731

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000731

BERE Be: lapsed

Owner name: BASF A.G.

Effective date: 20000731

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20010201

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20000715

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20010330

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20010201

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST