EP0711851A1 - Process for manufacturing p-hydroxybenzaldehyde - Google Patents
Process for manufacturing p-hydroxybenzaldehyde Download PDFInfo
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- EP0711851A1 EP0711851A1 EP95117495A EP95117495A EP0711851A1 EP 0711851 A1 EP0711851 A1 EP 0711851A1 EP 95117495 A EP95117495 A EP 95117495A EP 95117495 A EP95117495 A EP 95117495A EP 0711851 A1 EP0711851 A1 EP 0711851A1
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- butyl
- tert
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- process according
- hydroxybenzaldehyde
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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
- C25B3/23—Oxidation
Definitions
- the present invention relates to an improved process for the preparation of p-hydroxybenzaldehydes of the general formula I. in which the aromatic ring can carry 2 to 4 inert substituents X, by electrochemical oxidation of a phenol of the general formula II in the presence of an alkanol R1-OH, the radical R1 being a C1-C6 alkyl radical.
- the aldehydes I serve as intermediates for the production of pharmaceuticals, light and crop protection agents, stabilizers, antioxidants, colorants and fragrances.
- the object of the invention was to make the aldehydes I selectively accessible from phenols II in higher yields.
- the starting compounds I can carry inert substituents such as alkyl, alkoxy, alkoxycarbonyl, cyano or halogen radicals.
- substituents such as alkyl, alkoxy, alkoxycarbonyl, cyano or halogen radicals.
- those compounds of the general formula III are preferred among the starting compounds in which the radicals R2 and R3 independently of one another for C1-C18-alkyl radicals such as methyl, ethyl, n-propyl, iso-propyl, n-butyl , Iso-butyl and tert-butyl, but also for C1-C18 alkoxy radicals such as methoxy or ethoxy.
- the compounds of the formula II or III are commercially available or can be prepared by methods known per se.
- the electrochemical oxidation is carried out in the presence of an alkanol R1-OH, the radical R1 being a C1-C6 alkyl radical.
- Methanol is preferred.
- the electrolyte can contain a solvent which is inert under the electrolysis conditions, such as acetonitrile; however, the electrolysis is preferably carried out without such a solvent.
- concentration of the alkanol in the electrolyte is usually 50 to 98% by weight.
- the electrolyte also contains an organic or inorganic base.
- This base must be able to convert the phenol II or III into the corresponding phenol ion.
- amines for example tertiary amines such as triethylamine, are preferred, but alkali metal hydroxides such as NaOH and KOH and alkali metal alcoholates such as sodium methoxide and ethanolate are preferred.
- the bases are used in substoichiometric amounts, based on the phenol II or III. 0.01 to 0.9 are preferred. particularly preferably 0.25 to 0.7 equivalents of base are used per equivalent of phenol II or III.
- a further auxiliary electrolyte such as weakly basic or neutral salts is generally not necessary, so that work is preferably carried out without such auxiliary electrolytes.
- the process according to the invention is generally carried out at current densities of 0.1 to 20 A / dm2, preferably at 2 to 8 A / dm2.
- the amount of charge is usually 4 to 6 F / mol of starting compound.
- the temperature can be varied within wide limits. It can be -20 to 180 ° C, preferably 50 to 70 ° C. There is reduced pressure, normal pressure or overpressure, but preferably normal pressure or overpressure up to 3 bar.
- Precious metals such as platinum or oxides such as chromium and ruthenium oxide and mixed oxides such as Ti / RuO x can be considered as anode materials.
- Graphite and platinum electrodes are preferred.
- the electrolysis can be carried out batchwise or continuously.
- a partial stream of the reaction solution can be separated off and worked up, which generally makes up less than 5% by weight of the total stream.
- new starting solution is added to the reaction solution.
- the reaction solution is advantageously worked up by distilling off the alkanol R 1 OH.
- the residue is worked up hydrolytically, preferably in neutral or acid.
- Mineral acids such as sulfuric acid or organic acids such as acetic acid can be used for acidification. These acids are generally added to the reaction mixture in amounts of 1 to 10% by weight, based on the reaction mixture.
- the product is then either separated off as a solid or, after extraction with an organic solvent such as methyl tert-butyl ether or toluene, obtained by distillation.
- the alkanol R1-OH and optionally Recovered starting material II or III can be used in further batches.
- the process according to the invention allows selective production of the aldehydes I in high yield.
- Electrolyte composition :
- Electrolyte composition :
- Electrolyte composition :
- Electrolyte composition :
- Electrolyte composition :
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- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
Die vorliegende Erfindung betrifft ein verbessertes Verfahren zur Herstellung von p-Hydroxybenzaldehyden der allgemeinen Formel I
in der der aromatische Ring 2 bis 4 inerte Substituenten X tragen kann, durch elektrochemische Oxidation eines Phenols der allgemeinen Formel II
in Gegenwart eines Alkanols R¹-OH, wobei der Rest R¹ für einen C₁-C₆-Alkylrest steht.The present invention relates to an improved process for the preparation of p-hydroxybenzaldehydes of the general formula I.
in which the aromatic ring can carry 2 to 4 inert substituents X, by electrochemical oxidation of a phenol of the general formula II
in the presence of an alkanol R¹-OH, the radical R¹ being a C₁-C₆ alkyl radical.
Die Aldehyde I dienen als Zwischenprodukte für die Herstellung von Pharmazeutika, Licht- und Pflanzenschutzmitteln, Stabilisatoren, Antioxidantien, Farb- und Riechstoffen.The aldehydes I serve as intermediates for the production of pharmaceuticals, light and crop protection agents, stabilizers, antioxidants, colorants and fragrances.
Die elektrochemische Oxidation von 2,6-Di-tert.-butyl-4-methylphenol zu 3,5-Di-tert.-butyl-4-hydroxybenzaldehyd beschreiben H. Ohmori et al. in Chem. Pharm. Bull. 33 (1985) 4007. Die Reaktion wird in einem Gemisch von Methanol und Diethylether in Gegenwart stöchiometrischer Mengen Natirummethanolat und eines weiteren Hilfselektrolyten bei konstantem Potential durchgeführt. Die erzielte Ausbeute von 68 % läßt jedoch für eine wirtschaftliche technische Umsetzung des Verfahrens Wünsche offen.The electrochemical oxidation of 2,6-di-tert-butyl-4-methylphenol to 3,5-di-tert-butyl-4-hydroxybenzaldehyde is described by H. Ohmori et al. in Chem. Pharm. Bull. 33 (1985) 4007. The reaction is carried out in a mixture of methanol and diethyl ether in the presence of stoichiometric amounts of sodium methoxide and another auxiliary electrolyte at constant potential. The yield of 68%, however, leaves something to be desired for an economical technical implementation of the process.
Der Erfindung lag die Aufgabe zugrunde, die Aldehyde I aus Phenolen II in höheren Ausbeuten selektiv zugänglich zu machen.The object of the invention was to make the aldehydes I selectively accessible from phenols II in higher yields.
Demgemäß wurde eine Verbesserung des eingangs definierten Verfahrens gefunden, welche dadurch gekennzeichnet ist, daß man die Reaktion in Gegenwart von weniger als stöchiometrischen Mengen einer organischen oder anorganischen Base, die ein Phenol II in das entsprechende Phenolation überführen kann, durchführt, das Reaktionsgemisch hydrolytisch aufarbeitet und den Aldehyd I isoliert.Accordingly, an improvement of the process defined at the outset was found, which is characterized in that the reaction in the presence of less than stoichiometric amounts of an organic or inorganic base which is a phenol II in the corresponding phenol ion can be converted, carried out, the reaction mixture worked up hydrolytically and the aldehyde I isolated.
Die Ausgangsverbindungen I können inerte Substituenten wie Alkyl-, Alkoxy-, Alkoxycarbonyl-, Cyano- oder Halogenreste tragen. Im Hinblick auf ihre Verwendung als Zwischenprodukte sind unter den Ausgangsverbindungen solche Verbindungen der allgemeinen Formel III bevorzugt, in der die Reste R² und R³ unabhängig voneinander für C₁-C₁₈-Alkylreste wie Methyl, Ethyl, n-Propyl, iso-Propyl, n-Butyl, iso-Butyl und tert.-Butyl, aber auch für C₁-C₁₈-Alkoxyreste wie Methoxy oder Ethoxy stehen. Die Verbindungen der Formel II bzw. III sind im Handel erhältlich oder nach an sich bekannten Methoden herstellbar.
Besonders bevorzugt ist die Herstellung folgender Verbindungen:
3-Methyl-5-tert.-Butyl-4-hydroxybenzaldehyd, 3,5-Di-tert.-butyl-4-hydroxybenzaldehyd, 3,5-Di-n-butyl-4-hydroxybenzaldehyd, 3,5-Di-isopropyl-4-hydroxybenzaldehyd, 3,5-Diethyl-4-hydroxybenzaldehyd, 3,5-Dimethyl-4-hydroxybenzaldehyd, 3-tert.-Butyl-5-methyl-4-hydroxybenzaldehyd.The starting compounds I can carry inert substituents such as alkyl, alkoxy, alkoxycarbonyl, cyano or halogen radicals. With regard to their use as intermediates, those compounds of the general formula III are preferred among the starting compounds in which the radicals R² and R³ independently of one another for C₁-C₁₈-alkyl radicals such as methyl, ethyl, n-propyl, iso-propyl, n-butyl , Iso-butyl and tert-butyl, but also for C₁-C₁₈ alkoxy radicals such as methoxy or ethoxy. The compounds of the formula II or III are commercially available or can be prepared by methods known per se.
The preparation of the following compounds is particularly preferred:
3-methyl-5-tert-butyl-4-hydroxybenzaldehyde, 3,5-di-tert-butyl-4-hydroxybenzaldehyde, 3,5-di-n-butyl-4-hydroxybenzaldehyde, 3,5-di- isopropyl-4-hydroxybenzaldehyde, 3,5-diethyl-4-hydroxybenzaldehyde, 3,5-dimethyl-4-hydroxybenzaldehyde, 3-tert-butyl-5-methyl-4-hydroxybenzaldehyde.
Die elektrochemische Oxidation wird in Gegenwart eines Alkanols R¹-OH vorgenommen, wobei der Rest R¹ für einen C₁-C₆-Alkylrest steht. Bevorzugt ist Methanol. Der Elektrolyt kann ein unter den Elektrolysebedingungen inertes Lösungsmittel wie Acetonnitril enthalten; vorzugsweise führt man die Elektrolyse aber ohne ein solches Lösungsmittel aus. Die Konzentration des Alkanols im Elektrolyten beträgt in der Regel 50 bis 98 Gew.-%.The electrochemical oxidation is carried out in the presence of an alkanol R¹-OH, the radical R¹ being a C₁-C₆ alkyl radical. Methanol is preferred. The electrolyte can contain a solvent which is inert under the electrolysis conditions, such as acetonitrile; however, the electrolysis is preferably carried out without such a solvent. The concentration of the alkanol in the electrolyte is usually 50 to 98% by weight.
Weiterhin enthält der Elektrolyt eine organische oder anorganische Base. Diese Base muß in der Lage sein, das Phenol II bzw. III in das entsprechende Phenolation zu überführen. Im einzelnen kommen Amine, z.B. tertiäre Amine wie Triethylamin in Betracht, bevorzugt aber Alkalimetallhydroxide wie NaOH und KOH und Alkalimetallalkoholate wie Natriummethanolat und -ethanolat. Die Basen werden in unterstöchiometrischen Mengen, bezogen auf das Phenol II bzw. III, eingesetzt. Bevorzugt werden 0,01 bis 0,9, besonders bevorzugt 0,25 bis 0,7 Äquivalente Base pro Äquivalent Phenol II bzw. III verwendet.The electrolyte also contains an organic or inorganic base. This base must be able to convert the phenol II or III into the corresponding phenol ion. In particular, amines, for example tertiary amines such as triethylamine, are preferred, but alkali metal hydroxides such as NaOH and KOH and alkali metal alcoholates such as sodium methoxide and ethanolate are preferred. The bases are used in substoichiometric amounts, based on the phenol II or III. 0.01 to 0.9 are preferred. particularly preferably 0.25 to 0.7 equivalents of base are used per equivalent of phenol II or III.
Ein weiterer Hilfselektrolyt wie schwach basische oder neutrale Salze ist in der Regel nicht erforderlich, so daß bevorzugt ohne solche Hilfselktrolyten gearbeitet wird.A further auxiliary electrolyte such as weakly basic or neutral salts is generally not necessary, so that work is preferably carried out without such auxiliary electrolytes.
Das erfindungsgemäße Verfahren wird im allgemeinen bei Stromdichten von 0,1 bis 20 A/dm², bevorzugt bei 2 bis 8 A/dm² durchgeführt. Die Ladungsmenge beträgt in der Regel 4 bis 6 F/mol Ausgangsverbindung.The process according to the invention is generally carried out at current densities of 0.1 to 20 A / dm², preferably at 2 to 8 A / dm². The amount of charge is usually 4 to 6 F / mol of starting compound.
Die Temperatur kann in weiten Grenzen variiert werden. Sie kann -20 bis 180°C betragen, bevorzugt sind 50 bis 70°C. Dabei herrscht verminderter Druck, Normaldruck oder Überdruck, bevorzugt aber Normaldruck oder ein Überdruck bis 3 bar.The temperature can be varied within wide limits. It can be -20 to 180 ° C, preferably 50 to 70 ° C. There is reduced pressure, normal pressure or overpressure, but preferably normal pressure or overpressure up to 3 bar.
Als Reaktoren kommen geteilte oder ungeteilte Zellen in Betracht, von denen die letzteren bevorzugt sind.Divided or undivided cells are considered as reactors, the latter being preferred.
Als Anodenmaterialien kommen Edelmetalle wie Platin oder Oxide wie Chrom- und Rutheniumoxid sowie Mischoxide wie Ti/RuOx in Betracht. Bevorzugt sind Graphit- und Platinelektroden.Precious metals such as platinum or oxides such as chromium and ruthenium oxide and mixed oxides such as Ti / RuO x can be considered as anode materials. Graphite and platinum electrodes are preferred.
Als Kathodenmaterialien eignen sich allgemein Stahl, Eisen, Kupfer, Nickel, Zink und Kohle sowie Edelmetalle wie Platin; bevorzugt wird Graphit und Platin.Steel, iron, copper, nickel, zinc and coal as well as noble metals such as platinum are generally suitable as cathode materials; graphite and platinum are preferred.
Die Elektrolyse kann diskontinuierlich oder kontinuierlich ausgeführt werden. In einer kontinuierlichen Variante kann ein Teilstrom der Reaktionslösung abgetrennt und aufgearbeitet werden, der im allgemeinen weniger als 5 Gew.-% des Gesamtstroms ausmacht. In dem Maß wie Elektrolyt entnommen wird, wird der Reaktionslösung neue Ausgangslösung zugesetzt.The electrolysis can be carried out batchwise or continuously. In a continuous variant, a partial stream of the reaction solution can be separated off and worked up, which generally makes up less than 5% by weight of the total stream. As the electrolyte is removed, new starting solution is added to the reaction solution.
Die Aufarbeitung der Reaktionslösung geschieht vorteilhaft durch Abdestillieren des Alkanols R¹-OH. Der Rückstand wird hydrolytisch, vorzugsweise im Neutralen oder Sauren, aufgearbeitet. Zum Ansäuren können beispielsweise Mineralsäuren wie Schwefelsäure oder organische Säuren wie Essigsäure dienen. Diese Säuren werden dem Reaktionsgemisch in der Regel in Mengen von 1 bis 10 Gew.-%, bezogen auf das Reaktionsgemisch, zugesetzt. Das Produkt wird dann entweder als Feststoff abgetrennt oder nach Extraktion mit einem organischen Lösungsmittel wie Methyl-tert.-Butylether oder Toluol destillativ gewonnen. Das Alkanol R¹-OH und gegebenenfalls zurückgewonnes Ausgangsmaterial II bzw. III können in weiteren Ansätzen eingesetzt werden.The reaction solution is advantageously worked up by distilling off the alkanol R 1 OH. The residue is worked up hydrolytically, preferably in neutral or acid. Mineral acids such as sulfuric acid or organic acids such as acetic acid can be used for acidification. These acids are generally added to the reaction mixture in amounts of 1 to 10% by weight, based on the reaction mixture. The product is then either separated off as a solid or, after extraction with an organic solvent such as methyl tert-butyl ether or toluene, obtained by distillation. The alkanol R¹-OH and optionally Recovered starting material II or III can be used in further batches.
Das erfindungsgemäße Verfahren erlaubt eine selektive Herstellung der Aldehyde I in hoher Ausbeute.The process according to the invention allows selective production of the aldehydes I in high yield.
Alle Beispiele wurden in einer von unten angeströmten ungeteilten Durchflußelektrolysezelle mit Graphitelektroden im Abstand von 1 mm durchgeführt.
Der Elektrolyt wurde mit 550 l/h umgepumpt.
Die Aufarbeitung erfolgte erfindungsgemäß durch Hydrolyse des Reaktionsgemisches.
Nicht umgesetztes Substrat und Zwischenprodukt wurden durch Extraktion der wäßrigen Mutterlauge mit Methyl-tert.-Butylether (MTBE) nach Filtrat Ion des Produktes und Eindampfen der Mutterlauge aus der Umkristallisation des Produktes gewonnen. Die Angaben in Gew.-% beziehen sich auf den Gesamtreaktionsansatz.All examples were carried out in an undivided flow-through flow electrolysis cell with graphite electrodes at a distance of 1 mm.
The electrolyte was pumped around at 550 l / h.
Working up was carried out according to the invention by hydrolysis of the reaction mixture.
Unreacted substrate and intermediate product were obtained from the recrystallization of the product by extraction of the aqueous mother liquor with methyl tert-butyl ether (MTBE) after filtrate ion of the product and evaporation of the mother liquor. The percentages by weight relate to the overall reaction batch.
- 150 g (0,68 mol, 5 Gew.-%)150 g (0.68 mol, 5% by weight)
- 2,6-Di-tert.-butyl-4-methylphenol2,6-di-tert-butyl-4-methylphenol
- 61,4 g (0,34 mol, 0,6 Gew.-%)61.4 g (0.34 mol, 0.6% by weight)
- Natriummethylat als 30 %ige methanolische LösungSodium methylate as a 30% methanolic solution
- 2789 g2789 g
- MethanolMethanol
- Temperatur
- 58°C
- Stromdichte
- 4 A/dm²
- Ladungsmenge
- 4,7 F/mol
- temperature
- 58 ° C
- Current density
- 4 A / dm²
- Amount of charge
- 4.7 F / mol
Bezogen auf eingesetztes Substrat wurden isoliert (Angaben in mol-%):
148 g (0,66 mol, 93 %) 3,5-Di-tert.-butyl-4-hydroxybenzaldehydBased on the substrate used, the following were isolated (data in mol%):
148 g (0.66 mol, 93%) 3,5-di-tert-butyl-4-hydroxybenzaldehyde
Die Herstellung erfolgte in Analogie zu Beispiel 1, die Stromdichte betrug jedoch 8 A/dm².The production was carried out in analogy to Example 1, but the current density was 8 A / dm².
Bezogen auf eingesetztes Substrat wurden isoliert (Angaben in mol-%):
143 g (0,61 mol, 90 %) 3,5-Di-tert.-butyl-4-hydroxybenzaldehydBased on the substrate used, the following were isolated (data in mol%):
143 g (0.61 mol, 90%) 3,5-di-tert-butyl-4-hydroxybenzaldehyde
Die Herstellung erfolgte in Analogie zu Beispiel 1, jedoch betrug die Stromdichte 2 A/dm².The preparation was carried out in analogy to Example 1, but the current density was 2 A / dm².
Bezogen auf eingesetztes Substrat wurden isoliert (Angaben in mol-%):
146 g (0,62 mol, 91 %) 3,5-Di-tert.-butyl-4-hydroxybenzaldehydBased on the substrate used, the following were isolated (data in mol%):
146 g (0.62 mol, 91%) of 3,5-di-tert-butyl-4-hydroxybenzaldehyde
300 g (1,36 mol, 10 Gew.-%) 2,6-Di-tert.-butyl-4-methylphenol,
122 g (0,68 mol) Natriummethylat als 30 %ige methanolische Lösung,
2578 g Methanol.300 g (1.36 mol, 10% by weight) of 2,6-di-tert-butyl-4-methylphenol,
122 g (0.68 mol) of sodium methylate as a 30% methanolic solution,
2578 g of methanol.
Die Elektrolyse und Aufarbeitung erfolgte in Analogie zu Beispiel 1.The electrolysis and workup were carried out in analogy to Example 1.
Bezogen auf eingesetztes Substrat wurden isoliert (Angaben in mol-%):
289 g (1,24 mol, 91 %) 3,5-Di-tert.-butyl-3-hydroxybenzaldehydBased on the substrate used, the following were isolated (data in mol%):
289 g (1.24 mol, 91%) 3,5-di-tert-butyl-3-hydroxybenzaldehyde
Die Elektrolyse und Aufarbeitung erfolgte in Analogie zu Beispiel 4, jedoch betrug die Temperatur 40°C.The electrolysis and workup were carried out analogously to Example 4, but the temperature was 40 ° C.
Bezogen auf eingesetztes Substrat wurden isoliert (Angaben in mol-%(:
258 g (1,1 mol, 81 %) 3,5-Di-tert.-butyl-4-hydroxybenzaldehydRelative to the substrate used were isolated (data in mol% (:
258 g (1.1 mol, 81%) 3,5-di-tert-butyl-4-hydroxybenzaldehyde
300 g (1,36 mol, 10 Gew.-%) 2,6-Di-tert.-butyl-4-methylphenol
20,5 g (0,51 mol, 0,7 Gew.-%) Natriumhydroxid
2680 g Methanol
Elektrolyse und Aufarbeitung erfolgten in Analogie zu Beispiel 1.300 g (1.36 mol, 10% by weight) of 2,6-di-tert-butyl-4-methylphenol
20.5 g (0.51 mol, 0.7% by weight) sodium hydroxide
2680 g of methanol
Electrolysis and workup were carried out in analogy to Example 1.
Bezogen auf eingesetztes Substrat wurden isoliert (Angaben in mol-%):
271 g (1,2 mol, 85 %) 3,5-Di-tert.-butyl-4-hydroxybenzaldehydBased on the substrate used, the following were isolated (data in mol%):
271 g (1.2 mol, 85%) 3,5-di-tert-butyl-4-hydroxybenzaldehyde
- 150 g (0,68 mol, 5 Gew.-%)
- 2,6-Di-tert.-butyl-4-methylphenol
- 19,1 g (0,34 mol, 0,6 Gew.-%)
- Kaliumhydroxid
- 2830 g
- Methanol
- 150 g (0.68 mol, 5% by weight)
- 2,6-di-tert-butyl-4-methylphenol
- 19.1 g (0.34 mol, 0.6% by weight)
- Potassium hydroxide
- 2830 g
- Methanol
Bezogen auf eingesetztes Substrat wurden isoliert (Angaben in mol-%):
119 g (0,51 mol, 75 %) 3,5-Di-tert.-butyl-4-hydroxybenzaldehydBased on the substrate used, the following were isolated (data in mol%):
119 g (0.51 mol, 75%) 3,5-di-tert-butyl-4-hydroxybenzaldehyde
- 150 g (1,1 mol, 10 Gew.-%)150 g (1.1 mol, 10% by weight)
- 2,4,6-Trimethylphenol2,4,6-trimethylphenol
- 100 g (0,55 mol, 1 Gew.-%)100 g (0.55 mol, 1% by weight)
- Natriummethylat als 30 %ige methanolische LösungSodium methylate as a 30% methanolic solution
- 2750 g2750 g
- MethanolMethanol
- Temperatur
- 58°C
- Stromdichte
- 4 A/dm²
- Ladungsmenge
- 5 F/mol
- temperature
- 58 ° C
- Current density
- 4 A / dm²
- Amount of charge
- 5 F / mol
Bezogen auf eingesetztes Substrat wurden isoliert (Angaben in mol-%):
114 g (0,76 mol, 69 %) 3,5-Di-methyl-4-hydroxybenzaldehydBased on the substrate used, the following were isolated (data in mol%):
114 g (0.76 mol, 69%) 3,5-dimethyl-4-hydroxybenzaldehyde
Claims (7)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4440466 | 1994-11-15 | ||
| DE4440466A DE4440466A1 (en) | 1994-11-15 | 1994-11-15 | Process for the preparation of p-hydroxybenzaldehydes |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0711851A1 true EP0711851A1 (en) | 1996-05-15 |
| EP0711851B1 EP0711851B1 (en) | 1998-03-04 |
Family
ID=6533160
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP95117495A Expired - Lifetime EP0711851B1 (en) | 1994-11-15 | 1995-11-07 | Process for manufacturing p-hydroxybenzaldehyde |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0711851B1 (en) |
| JP (1) | JPH08209372A (en) |
| DE (2) | DE4440466A1 (en) |
| ES (1) | ES2113150T3 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006077483A2 (en) * | 2005-01-19 | 2006-07-27 | Merisol Rsa (Pty) Ltd | Method for the production of alkoxy-substituted phenols |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5227739A (en) * | 1975-08-26 | 1977-03-02 | Takasago Corp | Process for preparation of 3-substituted or non-substituted-4-hydroxyb enzaldehyde by electrolytic oxidation |
| JPS572881A (en) * | 1980-06-04 | 1982-01-08 | Otsuka Chem Co Ltd | Manufacture of 3,5-dialkoxy-4-hydroxybenzaldehyde |
-
1994
- 1994-11-15 DE DE4440466A patent/DE4440466A1/en not_active Withdrawn
-
1995
- 1995-11-07 DE DE59501538T patent/DE59501538D1/en not_active Expired - Lifetime
- 1995-11-07 ES ES95117495T patent/ES2113150T3/en not_active Expired - Lifetime
- 1995-11-07 EP EP95117495A patent/EP0711851B1/en not_active Expired - Lifetime
- 1995-11-13 JP JP7294256A patent/JPH08209372A/en not_active Withdrawn
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5227739A (en) * | 1975-08-26 | 1977-03-02 | Takasago Corp | Process for preparation of 3-substituted or non-substituted-4-hydroxyb enzaldehyde by electrolytic oxidation |
| JPS572881A (en) * | 1980-06-04 | 1982-01-08 | Otsuka Chem Co Ltd | Manufacture of 3,5-dialkoxy-4-hydroxybenzaldehyde |
Non-Patent Citations (2)
| Title |
|---|
| DATABASE WPI Section Ch Week 7715, Derwent World Patents Index; Class E14, AN 77-26085Y * |
| PATENT ABSTRACTS OF JAPAN vol. 006, no. 063 (C - 099) 22 April 1982 (1982-04-22) * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006077483A2 (en) * | 2005-01-19 | 2006-07-27 | Merisol Rsa (Pty) Ltd | Method for the production of alkoxy-substituted phenols |
| WO2006077483A3 (en) * | 2005-01-19 | 2006-10-05 | Merisol Rsa Pty Ltd | Method for the production of alkoxy-substituted phenols |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0711851B1 (en) | 1998-03-04 |
| DE59501538D1 (en) | 1998-04-09 |
| ES2113150T3 (en) | 1998-04-16 |
| DE4440466A1 (en) | 1996-05-23 |
| JPH08209372A (en) | 1996-08-13 |
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