EP0072914A1 - Process for the production of alkyl-substituted benzaldehydes - Google Patents
Process for the production of alkyl-substituted benzaldehydes Download PDFInfo
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- EP0072914A1 EP0072914A1 EP82106344A EP82106344A EP0072914A1 EP 0072914 A1 EP0072914 A1 EP 0072914A1 EP 82106344 A EP82106344 A EP 82106344A EP 82106344 A EP82106344 A EP 82106344A EP 0072914 A1 EP0072914 A1 EP 0072914A1
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- EP
- European Patent Office
- Prior art keywords
- alkyl
- oxide
- hydrogen atom
- coated
- substituted benzaldehydes
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- 238000000034 method Methods 0.000 title claims abstract description 16
- 150000003935 benzaldehydes Chemical class 0.000 title claims abstract description 10
- 238000004519 manufacturing process Methods 0.000 title description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 14
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 14
- 239000010439 graphite Substances 0.000 claims abstract description 14
- 238000006056 electrooxidation reaction Methods 0.000 claims abstract description 7
- 150000001247 metal acetylides Chemical class 0.000 claims abstract description 5
- 125000000217 alkyl group Chemical group 0.000 claims abstract description 4
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 4
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 4
- 238000002360 preparation method Methods 0.000 claims abstract description 4
- 239000002253 acid Substances 0.000 claims description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 6
- -1 alkyl radical Chemical class 0.000 claims description 6
- 125000004435 hydrogen atom Chemical group [H]* 0.000 claims description 6
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 5
- NUJOXMJBOLGQSY-UHFFFAOYSA-N manganese dioxide Chemical compound O=[Mn]=O NUJOXMJBOLGQSY-UHFFFAOYSA-N 0.000 claims description 4
- 150000005840 aryl radicals Chemical class 0.000 claims description 3
- 229910000428 cobalt oxide Inorganic materials 0.000 claims description 3
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 claims description 3
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 claims description 2
- 150000004997 alkyl benzene derivatives Chemical class 0.000 claims description 2
- 229910000423 chromium oxide Inorganic materials 0.000 claims description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims description 2
- 229910000480 nickel oxide Inorganic materials 0.000 claims description 2
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 claims description 2
- 229910001925 ruthenium oxide Inorganic materials 0.000 claims description 2
- WOCIAKWEIIZHES-UHFFFAOYSA-N ruthenium(iv) oxide Chemical compound O=[Ru]=O WOCIAKWEIIZHES-UHFFFAOYSA-N 0.000 claims description 2
- 239000004408 titanium dioxide Substances 0.000 claims description 2
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 claims description 2
- 150000004996 alkyl benzenes Chemical class 0.000 abstract description 5
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 10
- 238000005868 electrolysis reaction Methods 0.000 description 7
- 239000003792 electrolyte Substances 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 5
- 150000003839 salts Chemical class 0.000 description 5
- URLKBWYHVLBVBO-UHFFFAOYSA-N Para-Xylene Chemical group CC1=CC=C(C)C=C1 URLKBWYHVLBVBO-UHFFFAOYSA-N 0.000 description 4
- XBDQKXXYIPTUBI-UHFFFAOYSA-N dimethylselenoniopropionate Natural products CCC(O)=O XBDQKXXYIPTUBI-UHFFFAOYSA-N 0.000 description 4
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 235000011054 acetic acid Nutrition 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- QSCOAHKJRIJKQZ-UHFFFAOYSA-N (4-tert-butylphenyl)methyl acetate Chemical compound CC(=O)OCC1=CC=C(C(C)(C)C)C=C1 QSCOAHKJRIJKQZ-UHFFFAOYSA-N 0.000 description 2
- QCWXDVFBZVHKLV-UHFFFAOYSA-N 1-tert-butyl-4-methylbenzene Chemical compound CC1=CC=C(C(C)(C)C)C=C1 QCWXDVFBZVHKLV-UHFFFAOYSA-N 0.000 description 2
- WDCUPFMSLUIQBH-UHFFFAOYSA-N 4-Methylbenzyl alcohol acetate Chemical compound CC(=O)OCC1=CC=C(C)C=C1 WDCUPFMSLUIQBH-UHFFFAOYSA-N 0.000 description 2
- ZZLCFHIKESPLTH-UHFFFAOYSA-N 4-Methylbiphenyl Chemical compound C1=CC(C)=CC=C1C1=CC=CC=C1 ZZLCFHIKESPLTH-UHFFFAOYSA-N 0.000 description 2
- ARIREUPIXAKDAY-UHFFFAOYSA-N 4-butylbenzaldehyde Chemical compound CCCCC1=CC=C(C=O)C=C1 ARIREUPIXAKDAY-UHFFFAOYSA-N 0.000 description 2
- KMTDMTZBNYGUNX-UHFFFAOYSA-N 4-methylbenzyl alcohol Chemical compound CC1=CC=C(CO)C=C1 KMTDMTZBNYGUNX-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- 229910020808 NaBF Inorganic materials 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 150000001299 aldehydes Chemical class 0.000 description 2
- QUKGYYKBILRGFE-UHFFFAOYSA-N benzyl acetate Chemical compound CC(=O)OCC1=CC=CC=C1 QUKGYYKBILRGFE-UHFFFAOYSA-N 0.000 description 2
- 235000019445 benzyl alcohol Nutrition 0.000 description 2
- 150000003938 benzyl alcohols Chemical class 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- FVEINXLJOJPHLH-UHFFFAOYSA-N p-tert-Butylbenzyl alcohol Chemical compound CC(C)(C)C1=CC=C(CO)C=C1 FVEINXLJOJPHLH-UHFFFAOYSA-N 0.000 description 2
- 235000019260 propionic acid Nutrition 0.000 description 2
- IUVKMZGDUIUOCP-BTNSXGMBSA-N quinbolone Chemical compound O([C@H]1CC[C@H]2[C@H]3[C@@H]([C@]4(C=CC(=O)C=C4CC3)C)CC[C@@]21C)C1=CCCC1 IUVKMZGDUIUOCP-BTNSXGMBSA-N 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 1
- 229910004373 HOAc Inorganic materials 0.000 description 1
- PWATWSYOIIXYMA-UHFFFAOYSA-N Pentylbenzene Chemical compound CCCCCC1=CC=CC=C1 PWATWSYOIIXYMA-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 125000004423 acyloxy group Chemical group 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- 150000001555 benzenes Chemical class 0.000 description 1
- 229940007550 benzyl acetate Drugs 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- FPCJKVGGYOAWIZ-UHFFFAOYSA-N butan-1-ol;titanium Chemical compound [Ti].CCCCO.CCCCO.CCCCO.CCCCO FPCJKVGGYOAWIZ-UHFFFAOYSA-N 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 230000005518 electrochemistry Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 150000004673 fluoride salts Chemical class 0.000 description 1
- 235000019253 formic acid Nutrition 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical group 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000011133 lead Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 150000005172 methylbenzenes Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- WVDDGKGOMKODPV-ZQBYOMGUSA-N phenyl(114C)methanol Chemical compound O[14CH2]C1=CC=CC=C1 WVDDGKGOMKODPV-ZQBYOMGUSA-N 0.000 description 1
- 238000007750 plasma spraying Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 150000003242 quaternary ammonium salts Chemical class 0.000 description 1
- 150000003254 radicals Chemical class 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- JXKPEJDQGNYQSM-UHFFFAOYSA-M sodium propionate Chemical compound [Na+].CCC([O-])=O JXKPEJDQGNYQSM-UHFFFAOYSA-M 0.000 description 1
- 239000004324 sodium propionate Substances 0.000 description 1
- 235000010334 sodium propionate Nutrition 0.000 description 1
- 229960003212 sodium propionate Drugs 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 150000003871 sulfonates Chemical class 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
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 mixed 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. Mixtures of the coating materials mentioned can also be used, such as a mixture of iron oxide and cobalt oxide.
- alkyl radicals R 1 and R 2 in the starting materials of the formula II are, for example, those having 1 to 6, preferably 1 to 4, carbon atoms.
- aryl radicals R 1 phenyl radicals which may be substituted by alkyl, halogen, alkoxy and / or acyloxy groups may be mentioned.
- 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 1 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 which p-xylene, p-tert-butyltoluene, p-methylbenzyl alcohol, p-tert-butylbenzyl alcohol, p-methylbenzyl acetate and p- tert-Butylbenzyl acetate of particular technical interest.
- 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 process is, for example, between 1 and 15 A / dm 2 .
- the electrolysis can be carried out batchwise or continuously.
- the electrolysis discharges are preferably worked up by distillation.
- the electrolyte from water-alkanoic acid - conductive salt is expediently returned to the electrolysis.
- the graphite anodes to be used according to the invention can e.g. by coating the electrode base body with the help of thermal spray technology or by thermal decomposition of suitable connections.
- 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.
- 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.
- Anodes coated graphite anodes (coating see table)
- Electrolyte 16.2% by weight 4-tert. Butyltoluene (TBT) 1.6% by weight NaBF 4 8.2% by weight water 74.0% by weight acetic acid (HOAc)
- 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.
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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)
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
Abstract
Verfahren zur Herstellung von alkylsubstituerten Benzaldehyden durch Elektrooxidation von Alkylbenzolen unter Verwendung von Graphitanoden die mit Metalloxiden oder Carbiden beschichtet sind.Process for the preparation of alkyl substituted benzaldehydes by electrooxidation of alkylbenzenes using graphite anodes coated with metal oxides or carbides.
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 4 148 696 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
Nach dem neuen Verfahren, bei dem man die Benzaldehyde der Formel I 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 Beschichtungsnaterialien verwenden, wie ein Gemisch aus Eisenoxid und Kobaltoxid.According to the new process, in which the benzaldehydes of the formula I are obtained at high conversions in high material and current yields, graphite anodes are used which are mixed 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. Mixtures of the coating materials mentioned can also be used, such as a mixture of iron oxide and cobalt oxide.
Die Alkylreste R1 und R2 in den Ausgangsstoffen der Formel II sind z.B. solche mit 1 bis 6, vorzugsweise 1 bis 4 C-Atomen. Als Arylreste R1 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 R1 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 1 and R 2 in the starting materials of the formula II are, for example, those having 1 to 6, preferably 1 to 4, carbon atoms. As aryl radicals R 1 , phenyl radicals which may be substituted by alkyl, halogen, alkoxy and / or acyloxy groups may be mentioned. 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 1 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 which p-xylene, p-tert-butyltoluene, p-methylbenzyl alcohol, p-tert-butylbenzyl alcohol, p-methylbenzyl acetate and p- tert-Butylbenzyl acetate 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.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 process is, for example, between 1 and 15 A / dm 2 . The electrolysis can be carried out batchwise or continuously.
Die Aufarbeitung der Elektrolyseausträge erfolgt vorzugsweise destillativ. Der Elektrolyt aus Wasser-Alkansäure--Leitsalz wird zweckmäßigerweise zur Elektrolyse zurückgeführt.The electrolysis discharges are preferably worked up by distillation. The electrolyte from water-alkanoic acid - conductive 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 can e.g. by coating the electrode base body with the help of thermal spray technology or by thermal decomposition of suitable connections. 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. For example, 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 to be based on the electrosynthesis of 4-tert. Butylbenzaldehyde are explained in more detail:
Reaktionsverlauf:
Apparatur: ungeteilte ZelleApparatus: undivided cell
Anoden: beschichtete Graphitanoden (Beschichtung s. Tabelle)Anodes: coated graphite anodes (coating see table)
Elektrolyt: 16,2 Gew.% 4-tert. Butyltoluol (TBT) 1,6 Gew.% NaBF4 8,2 Gew.% Wasser 74,0 Gew.% Essigsäure (HOAc)Electrolyte: 16.2% by weight 4-tert. Butyltoluene (TBT) 1.6% by weight NaBF 4 8.2% by weight water 74.0% by weight acetic acid (HOAc)
Kathoden: GraphitCathodes: graphite
Stromdichte: 5,3 A/dm2 Current density: 5.3 A / d m 2
Temperatur: 55 bis 65°CTemperature: 55 to 65 ° C
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:
Claims (2)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19813132726 DE3132726A1 (en) | 1981-08-19 | 1981-08-19 | PROCESS FOR PRODUCING ALKYL-SUBSTITUTED BENZALDEHYDES |
| DE3132726 | 1981-08-19 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0072914A1 true EP0072914A1 (en) | 1983-03-02 |
| EP0072914B1 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) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0231053A1 (en) * | 1986-01-06 | 1987-08-05 | The Dow Chemical Company | Electrocatalytic method for producing quinone methides and dihydroxybenzophenones |
| US5078838A (en) * | 1989-04-21 | 1992-01-07 | Basf Aktiengesellschaft | Preparation of benzaldehyde dialkyl acetals and novel benzaldehyde dialkyl acetals and benzyl esters |
Families Citing this family (9)
| 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) |
| 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 |
| DE59200727D1 (en) * | 1991-09-19 | 1994-12-08 | Hoechst Ag | Process for the oxidation of hydroxymethylpyridine derivatives to pyridinecarboxylic acid derivatives. |
| US10156842B2 (en) | 2015-12-31 | 2018-12-18 | General Electric Company | Device enrollment in a cloud service using an authenticated application |
| CN120041877A (en) * | 2025-03-18 | 2025-05-27 | 浙江工业大学 | Nickel oxide doped manganese dioxide catalyst and preparation method and application thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2113795A1 (en) * | 1970-03-23 | 1971-10-28 | Diamond Shamrock Corp | Electrode, process for its manufacture and its use as an oxygen anode |
| 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 |
| EP0004386A2 (en) * | 1978-03-28 | 1979-10-03 | Diamond Shamrock Technologies S.A. | Electrodes for electrolytic processes, especially metal electrowinning |
| EP0012942A2 (en) * | 1978-12-22 | 1980-07-09 | BASF Aktiengesellschaft | Electrolytic process for producing benzaldehydes |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3977959A (en) * | 1973-09-13 | 1976-08-31 | Basf Aktiengesellschaft | Anodes for electrolysis |
| US4148696A (en) * | 1978-03-20 | 1979-04-10 | Uop Inc. | Electrochemical oxidation of activated alkyl aromatic compounds |
-
1981
- 1981-08-19 DE DE19813132726 patent/DE3132726A1/en not_active Withdrawn
-
1982
- 1982-07-15 EP EP82106344A patent/EP0072914B1/en not_active Expired
- 1982-07-15 DE DE8282106344T patent/DE3261133D1/en not_active Expired
- 1982-07-22 US US06/400,699 patent/US4411746A/en not_active Expired - Lifetime
- 1982-08-17 JP JP57141777A patent/JPS5845387A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2113795A1 (en) * | 1970-03-23 | 1971-10-28 | Diamond Shamrock Corp | Electrode, process for its manufacture and its use as an oxygen anode |
| 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 |
| EP0004386A2 (en) * | 1978-03-28 | 1979-10-03 | Diamond Shamrock Technologies S.A. | Electrodes for electrolytic processes, especially metal electrowinning |
| EP0012942A2 (en) * | 1978-12-22 | 1980-07-09 | BASF Aktiengesellschaft | Electrolytic process for producing benzaldehydes |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0231053A1 (en) * | 1986-01-06 | 1987-08-05 | The Dow Chemical Company | Electrocatalytic method for producing quinone methides and dihydroxybenzophenones |
| US5078838A (en) * | 1989-04-21 | 1992-01-07 | Basf Aktiengesellschaft | Preparation of benzaldehyde dialkyl acetals and novel benzaldehyde dialkyl acetals and benzyl esters |
Also Published As
| Publication number | Publication date |
|---|---|
| US4411746A (en) | 1983-10-25 |
| JPS5845387A (en) | 1983-03-16 |
| EP0072914B1 (en) | 1984-10-31 |
| DE3132726A1 (en) | 1983-03-03 |
| DE3261133D1 (en) | 1984-12-06 |
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