EP0902846A1 - Process for preparing phthalides - Google Patents

Process for preparing phthalides

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Publication number
EP0902846A1
EP0902846A1 EP97921810A EP97921810A EP0902846A1 EP 0902846 A1 EP0902846 A1 EP 0902846A1 EP 97921810 A EP97921810 A EP 97921810A EP 97921810 A EP97921810 A EP 97921810A EP 0902846 A1 EP0902846 A1 EP 0902846A1
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EP
European Patent Office
Prior art keywords
phthalic acid
alkyl
phthalides
hydrogen
anodic
Prior art date
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Granted
Application number
EP97921810A
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German (de)
French (fr)
Other versions
EP0902846B1 (en
Inventor
Hermann Pütter
Heinz Hannebaum
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BASF SE
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BASF SE
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    • 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
    • C25B3/25—Reduction

Definitions

  • a disadvantage of the described methods is the expenditure on equipment associated with the use of divided electrolysis cells, since in this case 2 cell circles are required.
  • working with 2 cell circles is associated with the following further disadvantages:
  • the cell circles must be separated by a membrane or a diaphragm; this means a loss of energy through ohmic heat.
  • at least one chamber is usually charged with an aqueous (> 80% H 2 O) conductive salt solution.
  • an aqueous (> 80% H 2 O) conductive salt solution In the case of cathodic reductions, this is the anolyte.
  • the compulsion to do so severely limits the scope for using the anode reaction. Normally only hydrogen is produced as the anode product. Furthermore, there is a risk with the known methods that anode corrosion and poisoning of the cathodes occur.
  • the technical problem underlying the invention was therefore to provide a technically simpler process for the production of phthalides in high purity and good yields, which does not have the disadvantages of the prior art and in particular the possibility of using the Anode reaction opened to produce products other than hydrogen.
  • R 1 , R 2 , R 3 and R 4 independently of one another hydrogen, C ⁇ ⁇ bis
  • R 5 and R 6 a) independently of one another -COOH or COOX, where X is Ci to C 4 alkyl,
  • R 5 and R 6 together -CO-O-CO-.
  • Particularly preferred are the derivatives of phthalic acid in which R 1, R 2, R 3 and R 4 are hydrogen and in particular the phthalic acid di (Ci to C 3 alkyl) esters, especially the dimethyl phthalate. 5
  • Electrodes made of graphite or carbon are particularly suitable as electrode materials (both cathode and anode).
  • the electrolyte is usually a 2 to 15 40% strength by weight solution of phthalic acid or a phthalic acid derivative in an organic solvent which preferably contains less than 25, particularly preferably less than 5% by weight of water.
  • Suitable organic solvents are, in particular, 0 aliphatic C ⁇ to Ca alcohols, in particular methanol or ethanol, or a mixture of such alcohols with a carboxamide such as dimethylformamide or t-butylformamide.
  • the electrolytes generally contain alkyl sulfates, for example methyl sulfate, or quaternary ammonium salts, in particular tetra (Ci to C 4 alkyl) ammonium halogens or tetrafluoroborates, usually in amounts of 0.4 to 10 wt. -% based on the electrolyte.
  • alkyl sulfates for example methyl sulfate
  • quaternary ammonium salts in particular tetra (Ci to C 4 alkyl) ammonium halogens or tetrafluoroborates, usually in amounts of 0.4 to 10 wt. -% based on the electrolyte.
  • anodic coupling process it is advisable to use conventional organic compounds as anodic depolarizer, the suitability of which is generally known to the person skilled in the art for the electrochemical oxidation.
  • Some of the anodic coupling processes are preferably carried out in the presence of a mediator. Possible 5 anodic coupling processes and their mediatization are described, for example, in D. Kyriakou, Modern Electroorganic Chemistry, Springer, Berlin 1994, in Chapter 4.2.
  • Halogen compounds especially bromides or iodides, are particularly suitable as mediators.
  • the other process parameters such as temperature and current density are concerned, these are not critical as long as they are within the normal range for electrochemical conversion of organic compounds. They are specified, for example, in DE-A-2 510 920.
  • an electrolysis cell consisting of ten bipolar switched ring disks made of graphite, area per side: 147 dm 2 , with an electrode spacing of 0.7 mm, a solution of 500 g dimethyl phthalate (2.56 mol), 1600 g t. -Butylformamide and 375 g of methanol with 25 g of tetrabutylammonium tetrafluoroborate at a current of 2.5 A for 11.5 h at 60 ° C electrolyzed.

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  • 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)
  • Furan Compounds (AREA)
  • Polysaccharides And Polysaccharide Derivatives (AREA)

Abstract

A process is disclosed for preparing phthalides by cathodic reduction of phthalic acid or phthalic acid derivatives, in which the carboxylic acid units may be substituted by units which can be derived by a condensation reaction from carboxylic acid units and in which one or several hydrogen atoms of the o-phenylene unit of the phthalic acid may be substituted by inert radicals. This process is characterised in that the reduction is carried out in an organic solvent which contains less than 50 wt % water and in a non-divided electrolytic cell.

Description

Verfahren zur Herstellung von PhthalidenProcess for the production of phthalides
Beschreibungdescription
Die vorliegende Erfindung betrifft ein neues Verfahren zur Her¬ stellung von Phthaliden durch kathodische Reduktion von Phthal- säurederivaten.The present invention relates to a new process for the production of phthalides by cathodic reduction of phthalic acid derivatives.
Phthalide werden insbesondere als Zwischenprodukte für die Her¬ stellung von Pflanzenschutzmitteln benötigt.Phthalides are required in particular as intermediates for the production of crop protection agents.
Ein elektrochemisches Verfahren zur Herstellung der Phthalide ist aus der DE-A-2 144 419 bekannt. Hierbei wird Ammoniumphthalamat in wässeriger Lösung mit einem Anteil organischer Lösungsmittel bis 50% bei Temperaturen bis 65°C an Metallen mit einer Wasser- stoffüberspannung größer als Cu, z.B. Blei, kathodisch reduziert. Unter diesen Bedingungen gelingt die Herstellung von Phthaliden in befriedigenden Ausbeuten, wenn man die Reduktion in geteilten Elektrolysezellen vornimmt.An electrochemical process for producing the phthalides is known from DE-A-2 144 419. Here, ammonium phthalamate in aqueous solution with a proportion of organic solvents up to 50% at temperatures up to 65 ° C of metals with a hydrogen overvoltage greater than Cu, e.g. Lead, reduced cathodically. Under these conditions, phthalides can be produced in satisfactory yields if the reduction is carried out in divided electrolysis cells.
Die Herstellung von besonders reinen Phthaliden ist in der DE-A-2 510 920 beschrieben. Nach dieser Lehre reduziert man ammoniakalische wässerige Lösungen von Phthalsäure oder Phthal- säureanhydrid kathodisch bei Temperaturen von bis zu 100°C an Metallen mit einer Wasserstoffüberspannung größer als Cu. Das Verfahren erfordert ebenfalls die Anwendung geteilter Elektro¬ lysezellen. Zur Abtrennung des Phthalids aus dem Elektrolyse- gemisch wird es gegebenenfalls nach Abtrennung von überschüssigem Ammoniak bei einer Temperatur von 35 bis 100°C angesäuert und das ausgefallene Phthalid abgetrennt.The production of particularly pure phthalides is described in DE-A-2 510 920. According to this teaching, ammoniacal aqueous solutions of phthalic acid or phthalic anhydride are reduced cathodically at temperatures of up to 100 ° C. on metals with a hydrogen overvoltage greater than Cu. The method also requires the use of divided electrolytic cells. To separate the phthalide from the electrolysis mixture, it is acidified, if appropriate after removal of excess ammonia, at a temperature of 35 to 100 ° C. and the precipitated phthalide is separated off.
Nachteilig an den beschriebenen Verfahren ist jedoch der mit der Verwendung von geteilten Elektrolysezellen verbundene apparative Aufwand, da in diesem Fall 2 Zellkreise erforderlich sind. Zudem ist das Arbeiten mit 2 Zellkreisen mit folgenden weiteren Nach¬ teilen verbunden:A disadvantage of the described methods, however, is the expenditure on equipment associated with the use of divided electrolysis cells, since in this case 2 cell circles are required. In addition, working with 2 cell circles is associated with the following further disadvantages:
Die Zellkreise müssen durch eine Membran oder ein Diaphragma ge- trennt werden; dies bedeutet einen Verlust an Energie durch ohm- sche Wärme. Um diesen Verlust zu minimieren, wird meist wenig¬ stens eine Kammer mit einer wäßrigen (> 80 % H2O) Leitsalzlösung beschickt. Bei kathodischen Reduktionen ist dies der Anolyt. Der Zwang zu diesem Vorgehen engt die Freiräume zur Nutzung der Ano- denreaktion stark ein. Normalerweise wird als Anodenprodukt le¬ diglich Wasserstoff erzeugt. Weiterhin besteht bei den vorbekannten Verfahren die Gefahr, daß eine Anodenkorrosion sowie eine Vergiftung der Kathoden auftritt.The cell circles must be separated by a membrane or a diaphragm; this means a loss of energy through ohmic heat. In order to minimize this loss, at least one chamber is usually charged with an aqueous (> 80% H 2 O) conductive salt solution. In the case of cathodic reductions, this is the anolyte. The compulsion to do so severely limits the scope for using the anode reaction. Normally only hydrogen is produced as the anode product. Furthermore, there is a risk with the known methods that anode corrosion and poisoning of the cathodes occur.
Die der Erfindung zugrunde liegende technische Aufgabe bestand deshalb darin, ein technisch einfacheres Verfahren zur Her¬ stellung von Phthaliden in hoher Reinheit und guten Ausbeuten zur Verfügung zu stellen, das die Nachteile des Standes der Technik nicht aufweist und insbesondere die Möglichkeit der Nut¬ zung der Anodenreaktion zur Herstellung von anderen Produkten als Wasserstoff eröffnet.The technical problem underlying the invention was therefore to provide a technically simpler process for the production of phthalides in high purity and good yields, which does not have the disadvantages of the prior art and in particular the possibility of using the Anode reaction opened to produce products other than hydrogen.
Demgemäß wurde ein Verfahren zur Herstellung von Phthaliden durch kathodische Reduktion von Phthalsäure oder Phthalsäurederivaten, bei denen die Carboxygruppen durch Einheiten ersetzt sein können, die von Carboxygruppen in einer Kondensationsreaktion ableitbar sind und eines oder mehrere der Wasserstoffatome der o-Phenylen- Einheit der Phthalsäure durch inerte Reste substituiert sein kön¬ nen, gefunden, wobei man die Reduktion in einem organischen Lösungsmittel, das weniger als 50 Gew.-% Wasser enthält und einer ungeteilten Elektrolysezelle vornimmt.Accordingly, a process for the preparation of phthalides by cathodic reduction of phthalic acid or phthalic acid derivatives, in which the carboxy groups can be replaced by units which can be derived from carboxy groups in a condensation reaction and one or more of the hydrogen atoms of the o-phenylene unit of phthalic acid by inert Residues can be substituted, the reduction being carried out in an organic solvent which contains less than 50% by weight of water and an undivided electrolysis cell.
Als Ausgangsverbindungen für die Herstellung der Phthalide sind insbesondere solche der allgemeinen Formel IStarting compounds for the preparation of the phthalides are, in particular, those of the general formula I.
R«R «
eingesetzt, in der die Substituenten die folgende Bedeutung haben: used in which the substituents have the following meaning:
R1, R2, R3 und R4: unabhängig voneinander Wasserstoff, Cι~ bisR 1 , R 2 , R 3 and R 4 : independently of one another hydrogen, Cι ~ bis
C4-Alkyl oder HalogenC 4 alkyl or halogen
R5 und R6: a) unabhängig voneinander -COOH oder COOX, wobei X für Ci- bis C4-Alkyl steht,R 5 and R 6 : a) independently of one another -COOH or COOX, where X is Ci to C 4 alkyl,
b) einer der Substituenten R5 oder R6 -COONY4 und der andere Substituent CONH2, wobei Y für Ci- bis C4-Alkyl oder Wasserstoff steht,b) one of the substituents R 5 or R 6 -COONY 4 and the other substituent CONH 2 , where Y is C 1 -C 4 -alkyl or hydrogen,
c) R5 und R6 zusammen -CO-O-CO-. Besonders bevorzugt sind die Derivate der Phthalsäure, bei denen Ri» R2» R 3 und R 4 Wasserstoff bedeutet und darunter insbesondere die Pththalsäuredi (Ci- bis C3-alkyl)-ester, vor allem der Phthal- säuredimethylester. 5c) R 5 and R 6 together -CO-O-CO-. Particularly preferred are the derivatives of phthalic acid in which R 1, R 2, R 3 and R 4 are hydrogen and in particular the phthalic acid di (Ci to C 3 alkyl) esters, especially the dimethyl phthalate. 5
Bei den Verbindungen der Formel I, bei denen R5 und R6 die unter b) aufgeführte Bedeutung haben, sind die Ammoniumsalze und ins¬ besondere das Ammoniumsalz der Phthalamidsäure besonders bevor¬ zugt. 10In the case of the compounds of the formula I in which R 5 and R 6 have the meaning given under b), the ammonium salts and in particular the ammonium salt of phthalamic acid are particularly preferred. 10
Als Elektrodenmaterialien (sowohl Kathode als auch Anode) eignen sich vor allem handelsübliche Elektroden aus Graphit oder Kohle.Commercial electrodes made of graphite or carbon are particularly suitable as electrode materials (both cathode and anode).
Bei dem Elektrolyten handelt es sich üblicherweise um eine 2 bis 15 40 gew.-%ige Lösung der Phthalsäure oder eines Phthalsäurederi- vates in einem organischen Lösungsmittel, das bevorzugt weniger als 25, besonders bevorzugt weniger als 5 Gew.-% Wasser enthält.The electrolyte is usually a 2 to 15 40% strength by weight solution of phthalic acid or a phthalic acid derivative in an organic solvent which preferably contains less than 25, particularly preferably less than 5% by weight of water.
Als organische Lösungsmittel eignen sich insbesondere 0 aliphatische Cι~ bis Ca-Alkohole, insbesondere Methanol oder Ethanol oder eine Mischungen derartiger Alkohole mit einem Carbonsäureamid wie Dimethylformamid oder t-Butylformamid.Suitable organic solvents are, in particular, 0 aliphatic C ~ to Ca alcohols, in particular methanol or ethanol, or a mixture of such alcohols with a carboxamide such as dimethylformamide or t-butylformamide.
Als Leitsalze enthalten die Elektrolyte im allgemeinen Alkyl- 5 sulfate, z.B. Methylsulfat, oder quartemäre Ammoniumsalze, ins¬ besondere Tetra(Ci- bis C4-alkyl)ammoniumhalogene oder -tetra- fluoroborate, üblicherweise in Mengen von 0,4 bis 10 Gew.-% bezogen auf den Elektrolyt.The electrolytes generally contain alkyl sulfates, for example methyl sulfate, or quaternary ammonium salts, in particular tetra (Ci to C 4 alkyl) ammonium halogens or tetrafluoroborates, usually in amounts of 0.4 to 10 wt. -% based on the electrolyte.
0 Für den anodischen Koppelprozeß empfiehlt es sich, als anodischen Depolarisator übliche organische Verbindungen einzusetzen, deren Eignung für die elektrochemische Oxidation dem Fachmann allgemein bekannt ist. Einige der anodischen Koppelprozessen werden bevor¬ zugt in Anwesenheit eines Mediators durchgeführt. Mögliche 5 anodische Koppelprozesse und deren Mediatisierung werden beispielsweise in D. Kyriakou, Modern Electroorganic Chemistry, Springer, Berlin 1994, in Kapitel 4.2 beschrieben.For the anodic coupling process, it is advisable to use conventional organic compounds as anodic depolarizer, the suitability of which is generally known to the person skilled in the art for the electrochemical oxidation. Some of the anodic coupling processes are preferably carried out in the presence of a mediator. Possible 5 anodic coupling processes and their mediatization are described, for example, in D. Kyriakou, Modern Electroorganic Chemistry, Springer, Berlin 1994, in Chapter 4.2.
Als anodische Koppelprozesse eignen sich insbesondere die 0 Oxidationen von C-O- oder C-N-Einfach- oder Doppelbindungen, z.B. die Oxidation von Carbonsäuren, Arylmethanen, Aldehyden, Carbon- säureamiden, Alkoholen sowie Heterocyclen, oder die oxidative C-Particularly suitable anodic coupling processes are the oxidations of C-O or C-N single or double bonds, e.g. the oxidation of carboxylic acids, arylmethanes, aldehydes, carboxamides, alcohols and heterocycles, or the oxidative C-
C-Verknüpfung insbesondere von Naphthalinen oder aktivierten CH-C-linkage, especially of naphthalenes or activated CH-
Gruppen. 5Groups. 5
Als Mediatoren eignen sich insbesondere Halogenverbindungen, vor allem Bromide oder lodide. Was die sonstigen Verfahrensparameter wie Temperatur und Strom¬ dichte betrifft, so sind diese unkritisch, solange sie sich im für elektrochemische Umsetzung organischer Verbindungen üblichen Rahmen bewegen. Sie sind beispielsweise in der DE-A-2 510 920 näher spezifiziert.Halogen compounds, especially bromides or iodides, are particularly suitable as mediators. As far as the other process parameters such as temperature and current density are concerned, these are not critical as long as they are within the normal range for electrochemical conversion of organic compounds. They are specified, for example, in DE-A-2 510 920.
Die Art Aufarbeitung des Elektrolytgemisches richtet sich ins¬ besondere nach der Art des anodischen Koppelproduktes und kann nach allgemein bekannten Trennmethoden wie Destillation, Fällung oder Umkristallisation erfolgen. Besonders einfach lassen sich die meisten Phthalide von vielen in basisch-wässerigem Milieu unlöslichen organischen Nebenprodukten abtrennen, indem man die Phthalide in ammoniakalischen wässerigen Lösungen löst, die wässerige Phase abtrennt und das Phthalid durch Ansäuern aus der wässerigen Phase wieder ausfällt (s. hierzu ebenfalls DE-A-2 510 920) .The way in which the electrolyte mixture is worked up depends in particular on the type of anodic coupling product and can be carried out by generally known separation methods such as distillation, precipitation or recrystallization. Most phthalides can be separated off particularly easily from many organic by-products which are insoluble in a basic aqueous medium by dissolving the phthalides in ammoniacal aqueous solutions, separating the aqueous phase and precipitating the phthalide from the aqueous phase by acidification (see also DE -A-2 510 920).
Nach dem erfindungsgemäßen Verfahren erhält man Phthalide auf technisch einfache Weise in hoher Ausbeute und Reinheit. Gleich- zeitig ist es möglich, durch Kopplung mit anodischen Oxidations- reaktionen verschiedenartige Wertprodukte herzustellen, ohne daß die Strom- und Materialausbeute an der Kathode sinken würde.The process according to the invention gives phthalides in a technically simple manner in high yield and purity. At the same time, it is possible to produce different types of valuable products by coupling with anodic oxidation reactions without the current and material yield at the cathode being reduced.
Beispiel 1example 1
Ausschließliche Produktion von Phthalid als WertproduktExclusive production of phthalide as a valuable product
In einer Elektrolysezelle, bestehend aus zehn bipolar geschalte¬ ten Ringscheiben aus Graphit, Fläche pro Seite: 147 dm2, mit einem Elektrodenabstand von 0,7 mm, wird eine Lösung aus 500 g Phthal- säuredimethylester (2,56 Mol), 1600 g t. -Butylformamid und 375 g Methanol mit 25 g Tetrabutylammoniumtetrafluoroborat bei einer Stromstärke von 2,5 A 11,5 h lang bei 60°C elektrolysiert.In an electrolysis cell, consisting of ten bipolar switched ring disks made of graphite, area per side: 147 dm 2 , with an electrode spacing of 0.7 mm, a solution of 500 g dimethyl phthalate (2.56 mol), 1600 g t. -Butylformamide and 375 g of methanol with 25 g of tetrabutylammonium tetrafluoroborate at a current of 2.5 A for 11.5 h at 60 ° C electrolyzed.
Nach Abdestillation des Lösemittelgemisches konnten in einer Vakuumdestillation bei 10 mbar 2,18 Mol Phthalid entsprechend 85 % gewonnen werden.After distilling off the solvent mixture, 2.18 mol of phthalide corresponding to 85% could be obtained in a vacuum distillation at 10 mbar.
Das Lösemittel t-Butylformamid wird unzersetzt zurückgewonnen, der Anodenprozeß ist die Methanoloxidation mit dem Hauptprodukt Methylformiat. Beispiel 2The solvent t-butylformamide is recovered without decomposition, the anode process is the methanol oxidation with the main product methyl formate. Example 2
Koppelproduktion von Phthalid und N-Methoxymethyl-N-Methyl- formamidCo-production of phthalide and N-methoxymethyl-N-methylformamide
In einer Elektrolysezelle gemäß Beispiel 1 wurden 2,56 Mol Phthalsauredimethylester, 750 g Methanol, 1225 g Dimethylformamid (DMF) und 25 g Triethylmethylammoniummethosulfat bei 5 A für 6,9 h bei 50°C elektrolysiert. Es entstanden 4,1 Mol (Strom- ausbeute: 64 %)2.56 mol of dimethyl phthalate, 750 g of methanol, 1225 g of dimethylformamide (DMF) and 25 g of triethylmethylammonium methosulfate at 5 A for 6.9 h at 50 ° C. were electrolyzed in an electrolysis cell according to Example 1. 4.1 moles were produced (current yield: 64%)
N-Methoxymethyl-N-Methylformamid neben 2,1 Mol Phthalid (Materialausbeute: 82 %) .N-methoxymethyl-N-methylformamide in addition to 2.1 moles of phthalide (material yield: 82%).
Beispiele 3 bis 9Examples 3 to 9
Analog zu Beispiel 2 wurde mit den jeweils in Tabelle 1 ange¬ gebenen Ausgangsstoffen Phthalid und unterschiedliche anodische Koppelprodukte hergestellt. Analogously to Example 2, phthalide and different anodic coupling products were produced with the starting materials given in Table 1.
Tabelle 1Table 1
-1' Gew. -%, bezogen auf das Methanol - 1 % by weight, based on the methanol

Claims

Patentansprüche claims
1. Verfahren zur Herstellung von Phthaliden durch kathodische Reduktion von Phthalsäure oder PhthalSäurederivaten, bei denen die Carboxygruppen durch Einheiten ersetzt sein können, die von Carboxygruppen in einer Kondensationsreaktion ableit¬ bar sind und eines oder mehrere der Wasserstoffatome der o- Phenylen-Einheit der Phthalsäure durch inerte Reste substi- tuiert sein können, dadurch gekennzeichnet, daß man die Re¬ duktion in einem organischen Lösungsmittel, das weniger als 50 Gew.-% Wasser enthält und einer ungeteilten Elektrolyse¬ zelle vornimmt.1. Process for the preparation of phthalides by cathodic reduction of phthalic acid or phthalic acid derivatives, in which the carboxy groups can be replaced by units which can be derived from carboxy groups in a condensation reaction and one or more of the hydrogen atoms of the o-phenylene unit of phthalic acid Inert radicals can be substituted, characterized in that the reduction is carried out in an organic solvent which contains less than 50% by weight of water and an undivided electrolysis cell.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß man2. The method according to claim 1, characterized in that one
Phthalsäure oder Phthalsäurederivate der allgemeinen Formel IPhthalic acid or phthalic acid derivatives of the general formula I
einsetzt, in der die Substituenten die folgende Bedeutung haben: in which the substituents have the following meaning:
R1, R2, R3 und R4: unabhängig voneinander Wasserstoff,R 1 , R 2 , R 3 and R 4 : independently of one another hydrogen,
Ci- bis C4~Alkyl oder HalogenCi to C4 ~ alkyl or halogen
R5, R6: a) unabhängig voneinander -C0OH oderR 5 , R 6 : a) independently of one another -C0OH or
COOX, wobei X für Ci- bis C4-Alkyl steht,COOX, where X is Ci to C 4 alkyl,
b) einer der Substituenten R5 oder R6 b) one of the substituents R 5 or R 6
-COONY4 und der andere Substituent CONH2, wobei Y für Ci- bis C4-Alkyl oder Wasserstoff steht,-COONY 4 and the other substituent CONH 2 , where Y is C 1 -C 4 -alkyl or hydrogen,
c) R5 und R6 zusammen -CO-O-CO-.c) R 5 and R 6 together -CO-O-CO-.
3. Verfahren nach Anspruch 1 oder 2, wobei man als Phthalsäure¬ derivate Phthalsäuredi (Ci- bis C3-alkyl) -ester einsetzt. 3. The method according to claim 1 or 2, wherein phthalic acid di (Ci to C 3 alkyl) ester is used as the phthalic acid derivative.
4. Verfahren nach den Ansprüchen 1 bis 3, wobei man Graphit¬ oder Kohleelektroden einsetzt.4. The method according to claims 1 to 3, wherein graphite or carbon electrodes are used.
5. Verfahren nach den Ansprüchen 1 bis 4, wobei man als organi- sches Lösungsmittel einen aliphatischen C±- bis C4-Alkohol oder eine Mischung eines derartigen Alkohols mit einem Carbonsäureamid einsetzt.5. The method according to claims 1 to 4, wherein the organic solvent used is an aliphatic C ± to C 4 alcohol or a mixture of such an alcohol with a carboxamide.
6. Verfahren nach den Ansprüchen 1 bis 5, wobei man als Leitsalz ein quarternäres Ammoniumsalz einsetzt.6. The method according to claims 1 to 5, wherein a quaternary ammonium salt is used as the conductive salt.
7. Verfahren nach den Ansprüchen 1 bis 6, wobei man für den anodischen Koppelprozeß als anodischen Depolarisator eine übliche organische Verbindung einsetzt, die sich für die elektrochemische Oxidation eignet.7. The method according to claims 1 to 6, wherein a conventional organic compound is used for the anodic coupling process as an anodic depolarizer, which is suitable for electrochemical oxidation.
8. Verfahren nach den Ansprüchen 1 bis 7, wobei man als Mediator für den anodischen Koppelprozeß eine Halogenverbindung ein¬ setzt.8. The method according to claims 1 to 7, wherein a halogen compound is used as mediator for the anodic coupling process.
Verfahren nach Anspruch 8, wobei man als Mediator Bromid oder Iodid einsetzt. A method according to claim 8, wherein the mediator is bromide or iodide.
EP97921810A 1996-05-10 1997-04-28 Process for preparing phthalides Expired - Lifetime EP0902846B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19618854 1996-05-10
DE19618854A DE19618854A1 (en) 1996-05-10 1996-05-10 Process for the production of phthalides
PCT/EP1997/002185 WO1997043464A1 (en) 1996-05-10 1997-04-28 Process for preparing phthalides

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EP0902846A1 true EP0902846A1 (en) 1999-03-24
EP0902846B1 EP0902846B1 (en) 2000-07-26

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US (1) US6063256A (en)
EP (1) EP0902846B1 (en)
JP (1) JP3946260B2 (en)
CN (1) CN1058302C (en)
CA (1) CA2254788C (en)
DE (2) DE19618854A1 (en)
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DE19741423A1 (en) * 1997-09-19 1999-03-25 Basf Ag Pure phthalide or derivative preparation in high yield
DE19808296A1 (en) * 1998-02-27 1999-09-02 Basf Ag Process for the selective hydrolysis of acetals or ketals in the presence of phthalides
DE19944990A1 (en) 1999-09-20 2001-03-22 Basf Ag Process for the electrolytic conversion of organic compounds
DE19944989A1 (en) 1999-09-20 2001-03-22 Basf Ag Process for the electrolytic conversion of furan derivatives
CN1182127C (en) * 2000-06-28 2004-12-29 中国医学科学院药物研究所 Novel substituted 2-benzo[c]furanone compounds, processes for their preparation and pharmaceutical compositions containing them
DE10057888A1 (en) 2000-11-22 2002-05-23 Basf Ag Production of butanetetracarboxylic acid derivatives useful as intermediates for e.g. plant protectants, dyes, complexing agents, polymers by cathodic reduction of maleate or fumarate esters and producing co-product at anode
DE10058304A1 (en) * 2000-11-24 2002-05-29 Basf Ag Process for the preparation of alkoxylated carbonyl compounds by an anodic oxidation process using the cathodic coupling reaction for organic synthesis
KR20150023709A (en) * 2012-06-15 2015-03-05 바스프 에스이 Anodic oxidation of organic substrates in the presence of nucleophiles

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DE2510920A1 (en) * 1975-03-13 1976-09-30 Basf Ag Electrochemical prepn of phthalide - from phthalic acid or anhydride, with final acidificn at controlled temp
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CA2254788C (en) 2005-03-01
DE19618854A1 (en) 1997-11-13
EP0902846B1 (en) 2000-07-26
CA2254788A1 (en) 1997-11-20
CN1210564A (en) 1999-03-10
WO1997043464A1 (en) 1997-11-20
CN1058302C (en) 2000-11-08
JP3946260B2 (en) 2007-07-18
US6063256A (en) 2000-05-16
DE59702087D1 (en) 2000-08-31
JP2000511592A (en) 2000-09-05

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