EP0000519B1 - Process for the preparation of 2,2'-dichlorohydrazobenzene - Google Patents
Process for the preparation of 2,2'-dichlorohydrazobenzene Download PDFInfo
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- EP0000519B1 EP0000519B1 EP78100394A EP78100394A EP0000519B1 EP 0000519 B1 EP0000519 B1 EP 0000519B1 EP 78100394 A EP78100394 A EP 78100394A EP 78100394 A EP78100394 A EP 78100394A EP 0000519 B1 EP0000519 B1 EP 0000519B1
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- anthraquinone
- reduction
- nitrochlorobenzene
- dichlorohydrazobenzene
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C241/00—Preparation of compounds containing chains of nitrogen atoms singly-bound to each other, e.g. hydrazines, triazanes
- C07C241/02—Preparation of hydrazines
Definitions
- the invention relates to a process for the preparation of 2,2'-dichlorohydrazobenzene by catalytic reduction of o-nitrochlorobenzene with hydrogen.
- the temperature is between 40-100 ° C, preferably at 60 to 70 ° C, the hydrogen (over) pressure at about 0.4 to 7.8 bar (20-125 psi, abs.), Preferably about 0.75 to 1.8 bar (25-40 psi, abs.).
- the hydrogen (over) pressure at about 0.4 to 7.8 bar (20-125 psi, abs.), Preferably about 0.75 to 1.8 bar (25-40 psi, abs.).
- naphthalene derivatives such as naphthoquinone- (1,4) or 2,3-dichloro-naphthoquinone- (1,4) are added to the reaction mixture.
- the yields of 2,2'-dichlorohydrazobenzene obtained in this way vary between 80 and 90%, and the chlorine elimination is said to be low.
- anthraquinone preferably hydroxyanthraquinones, for example ⁇ -hydroxyanthraquinone or 2,6-dihydroxyanthraquinone, can be added.
- the noble metal catalysts can be recycled very often when the anthraquinone derivatives are used, without suffering a drop in activity. Even after e.g. Ten times the precious metal catalysts are used, constant yields are obtained in the same reduction time as in the starting batch.
- the anthraquinone derivatives accelerate the reduction of the individual reaction stages, in particular the azoxy and azo stage, much more strongly than naphthoquinone compounds, so that a lower temperature is made possible during the entire reaction time, and even shorter reaction times are achieved than when using the known naphthoquinones.
- Another advantage is that e.g. the ß-hydroxyanthraquinone after the reduction from the aqueous mother liquor by setting a pH of 3 to 4 can be precipitated practically quantitatively and can be reused several times without purification, while the 2-hydroxy-3-chloro-naphthoquinone- (1,4) (formed during the reduction from 2,3-dichloronaphthoquinone (1,4)) has to be eliminated by a complex wastewater treatment.
- the amount of anthraquinones used is small, it is lower than that of the naphthoquinone derivatives.
- a weight ratio of ß-hydroxyanthraquinone to o-chloronitrobenzene of 0.003 to 0.008, in particular 0.004: 1 is sufficient to evenly reduce the dichlorazoxybenzene which occurs as an intermediate via the dichlorazobenzene through to the hydrazo compound, while of 2,3-dichloronaphthoquinone- (1,4) twice the amount is necessary in order to achieve comparable results at least when the noble metal catalysts are used for the first time.
- a 16 to 25% sodium hydroxide solution is used as the reaction medium in such an amount that, after the reaction has ended, a 10 to 15% sodium hydroxide solution is produced by the water of reaction formed concentration arises.
- anthraquinones show advantages over the naphthoquinones. While the best results are achieved with naphthoquinone with a 16% sodium hydroxide solution in a weight ratio of o-nitrochlorobenzene to NaOH (100%) such as 1: 0.095, the anthraquinones allow an increase in the NaOH concentration up to 25% and a lower use of sodium hydroxide solution in a weight ratio of o-nitrochlorobenzene to NaOH (100%) such as 1:: 0.071, without slowing down the reaction rate.
- the use of an approx. 25% NaOH means an improvement in the space yield of approx. 20% compared to a 16% NaOH according to the above weight ratios.
- the reaction temperature is preferably between 55 to 60 ° C., the hydrogen pressure preferably between 1 to 6 bar, it being advantageous to let the pressure rise slowly within the specified limit values during the reduction.
- the reduction is carried out particularly advantageously in such a way that o-nitrochlorobenzene, aqueous sodium hydroxide solution, the anthraquinone derivative, e.g. ß-Hydroxyanthraquinone, solvent, an emulsifier and a noble metal catalyst are filled into a conventional autoclave and, after the air has been displaced, heated with nitrogen while stirring. The nitrogen is replaced by hydrogen and hydrogen is pressed on until there is no more pressure drop. The desired reaction temperature is maintained by external cooling or heating.
- the catalyst is filtered off under nitrogen and returned to the next reduction batch without purification, it being possible to use it at least ten times.
- the o-chloroaniline is washed out with dilute hydrochloric acid, the solvent is distilled off and the hydrazo compound is dried. Since the product is obtained in sufficient purity, the organic phase can also be fed directly to the rearrangement with mineral acids to give 3,3'-dichlorobenzidine.
- the process according to the invention thus makes it possible to produce 2,2'-dichlorohydrazobenzene in a particularly economical manner by catalytic reduction of o-nitrochlorobenzene in the presence of anthraquinones in high yields and in a reproducible manner.
- the advantages of the method according to the invention are explained in more detail in the following examples. The percentages relate to the weight, unless stated otherwise.
- the reaction mixture After the air has been displaced in a closed autoclave with nitrogen, the reaction mixture is heated to 60 ° C. with stirring and hydrogen is injected to 3 bar. Depending on the hydrogen uptake, the hydrogen pressure is increased to 6 bar by the end of the reduction. The reduction is complete when the uptake of hydrogen ceases, which is the case after 5 hours.
- the reaction mixture After the end of the reaction, the reaction mixture is heated to 80 ° C. and the palladium-carbon catalyst is filtered off at this temperature. The filtrate is diluted with 600 ml of "solvent naphtha" and the organic phase, which contains the 2,2'-dichlorohydrazobenzene and the o-chloroaniline formed as a by-product, is separated from the aqueous phase.
- the o-chloroaniline is dissolved out in a customary manner by washing twice with 5% hydrochloric acid and the “solvent naphtha” is removed in vacuo.
- the filtered-off palladium-on-carbon catalyst is used at least ten times without purification and the reduction is carried out in the same way. In all subsequent batches, the same yield of 2,2'-dichlorohydrazobenzene as in the starting batch is obtained without reducing the quality.
- the reduction time is constantly around 5 hours.
- the chlorine elimination is determined in the aqueous phase by potentiometric titration and is max. 4%, based on o-nitrochlorobenzene.
- Example 1 is repeated, but 5 g of 2,3-dichloronaphthoquinone- (1,4) is used instead of the hydroxyanthraquinone.
- the reaction stops at a reaction temperature of 60 ° C and can now be completed by increasing the reaction temperature to 80 ° C.
- the yield is 80% of theory, based on o-nitrochlorobenzene. The reduction takes 6.25 hours.
- the yield is 83% of theory of 2,2'-dichlorohydrazobenzene, based on o-nitrochlorobenzene, with a melting point of 84 to 86 ° C, the reaction time is 5 hours. After recycling the platinum catalyst ten times, the yields and the reaction times are constant. The release of chlorine is max. 1.7% of theory, based on o-nitrochlorobenzene.
- Example 2 The procedure is as in Example 1, but instead of the palladium catalyst 0.25 g of platinum, in the form of 10 g of sulfited 5% platinum-on-carbon catalyst with 50% water content (corresponding to DE-PS 2.105.780) .
- the yield is 83 96 th. of 2,2-dichlorohydrazobenzene, based on o-nitrochlorobenzene, with a melting point of 85 to 86 ° C, the reaction time is 5 hours. After recycling the platinum catalyst ten times, the yields and the reaction times were constant.
- the release of chlorine is max. 0.7% of theory, based on o-nitrochlorobenzene.
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Description
Die Erfindung betrifft ein Verfahren zur Herstellung von 2,2'-Dichlorhydrazobenzol durch katalytische Reduktion von o-Nitrochlorbenzol mit Wasserstoff.The invention relates to a process for the preparation of 2,2'-dichlorohydrazobenzene by catalytic reduction of o-nitrochlorobenzene with hydrogen.
Aus der US-PS 3.156.724 ist bekannt, 2,2'-Dichlorhydrazobenzol durch katalytische Hydrierung von o-Nitrochlorbenzol herzustellen. Der Hydrierkontakt besteht aus Palladium oder Platin. Als Reaktionsmedium dient eine 2 bis 20 %ige wäßrige Lösung von Natrium- oder Kaliumhydroxid, insbesondere 13 bis 14 %ige Natronlauge, gegebenenfalls unter Zusatz eines organischen Lösemittels, vorzugsweise eines nicht wassermischbaren aromatischen Kohlenwasserstoffs wie Benzol, Toluol oder Xylol. Die Temperatur liegt zwischen 40-100°C, vorzugsweise bei 60 bis 70°C, der Wasserstoff(über)druck bei etwa 0,4 bis 7,8 bar (20-125 psi,abs.), vorzugsweise etwa 0,75 bis 1,8 bar (25-40 psi,abs.). Für die Bildung von 2,2'-Dichlorhydrazobenzol werden dem Reaktionsgemisch Zusätze von Naphthalinderivaten, wie Naphthochinon-(1,4) oder 2,3-Dichlor-naphthochinon-(1,4) zugegeben. Die so erhaltenen Ausbeuten an 2,2'-Dichlorhydrazobenzol variieren zwischen 80 und 90 %, die Chlorabspaltung soll gering sein.From US-PS 3,156,724 it is known to produce 2,2'-dichlorohydrazobenzene by catalytic hydrogenation of o-nitrochlorobenzene. The hydrogenation contact consists of palladium or platinum. A 2 to 20% aqueous solution of sodium or potassium hydroxide, in particular 13 to 14% sodium hydroxide solution, optionally with the addition of an organic solvent, preferably a water-immiscible aromatic hydrocarbon such as benzene, toluene or xylene, serves as the reaction medium. The temperature is between 40-100 ° C, preferably at 60 to 70 ° C, the hydrogen (over) pressure at about 0.4 to 7.8 bar (20-125 psi, abs.), Preferably about 0.75 to 1.8 bar (25-40 psi, abs.). For the formation of 2,2'-dichlorohydrazobenzene, additions of naphthalene derivatives such as naphthoquinone- (1,4) or 2,3-dichloro-naphthoquinone- (1,4) are added to the reaction mixture. The yields of 2,2'-dichlorohydrazobenzene obtained in this way vary between 80 and 90%, and the chlorine elimination is said to be low.
Wie eine Nacharbeitung ergab, fallen bei einem erneuten Einsatz der Edelmetallkatalysatoren von Ansatz zu Ansatz nicht nur die Ausbeuten ab, sondern gleichzeitig steigen die Reaktionszeiten bei sinkender Aktivität der Edelmetallkatalysatoren. Beides ist für eine wirtschaftliche Durchführung der Reduktion unerwünscht. Die Chlorabspaltung liegt mit 7 bis 8 % schon beim ersten Einsatz recht hoch.As a rework showed, when the noble metal catalysts are used again, not only do the yields drop from batch to batch, but at the same time the reaction times increase as the activity of the noble metal catalysts decreases. Both are undesirable for an economical implementation of the reduction. At 7 to 8%, the elimination of chlorine is quite high the first time it is used.
Es wurde nun überraschend gefunden, daß die katalytische Reduktion von o-Nitrochlorbenzol zu 2,2'-Dichlorhydrazobenzol mit Wasserstoff in wäßriger Natron- oder Kalilauge, insbesondere einer 10 bis 25 gewichtsprozentigen Natronlauge, und in Gegenwart eines nicht wassermischbaren aromatischen Lösemittels, insbesondere eines Kohlenwasserstoffs wie Benzol, Toluol oder Xylol, mit Edelmetallkatalysatoren, vorzugsweise Palladium-, Platin- oder modifizierten beispielsweise sulfidierten (gemäß DE-PS 1.959.578), insbesondere sulfitierten Platin-auf-Kolenstoff-Katalysatoren (gemäß DE-PS 2.105.780) bei einem Wasserstoff(über)druck von 1 bis etwa 10, vorzugsweise bis 6 bar und einer Reduktionstemperatur von etwa 50 bis 80, insbesondere 60°C zu hohen und gut reproduzierbaren Ausbeuten führt, wenn als CoKatalysatoren Derivate des Anthrachinons, vorzugsweise Hydroxyanthrachinone, z.B. ß-Hydroxyanthrachinon oder 2,6-Dihydroxyanthrachinon, zugesetzt werden.It has now surprisingly been found that the catalytic reduction of o-nitrochlorobenzene to 2,2'-dichlorohydrazobenzene with hydrogen in aqueous sodium hydroxide solution or potassium hydroxide solution, in particular a 10 to 25% strength by weight sodium hydroxide solution, and in the presence of a water-immiscible aromatic solvent, in particular a hydrocarbon such as benzene, toluene or xylene, with noble metal catalysts, preferably palladium, platinum or modified, for example sulfidated (according to DE-PS 1,959,578), in particular sulfited platinum-on-kolene catalysts (according to DE-PS 2,105,780) in one Hydrogen (excess) pressure from 1 to about 10, preferably up to 6 bar and a reduction temperature of about 50 to 80, in particular 60 ° C. leads to high and readily reproducible yields if, as cocatalysts, derivatives of anthraquinone, preferably hydroxyanthraquinones, for example β-hydroxyanthraquinone or 2,6-dihydroxyanthraquinone, can be added.
Von besonderem Vorteil ist, daß die Edelmetallkatalysatoren bei Verwendung der Anthrachinonderivate sehr oft zurückgeführt werden können, ohne daß sie einen Aktivitätsabfall erleiden. Selbst nach z.B. zehnmaligem Einsatz der Edelmetallkatalysatoren werden konstante Ausbeuten in der gleichen Reduktionszeit wie beim Startansatz erhalten.It is particularly advantageous that the noble metal catalysts can be recycled very often when the anthraquinone derivatives are used, without suffering a drop in activity. Even after e.g. Ten times the precious metal catalysts are used, constant yields are obtained in the same reduction time as in the starting batch.
Die Anthrachinonderivate beschleunigen die Reduktion der einzelnen Reaktionsstufen, insbesondere der Azoxy- und Azostufe, wesentlich stärker als Naphthochinonverbindungen, so daß eine niedrigere Temperatur während der gesamten Reaktionszeit ermöglicht wird und dabei noch kürzere Reaktionszeiten als bei Einsatz der bekannten Naphthochinone erzielt werden.The anthraquinone derivatives accelerate the reduction of the individual reaction stages, in particular the azoxy and azo stage, much more strongly than naphthoquinone compounds, so that a lower temperature is made possible during the entire reaction time, and even shorter reaction times are achieved than when using the known naphthoquinones.
Zusätzlich erfolgt eine wesentlich geringere Chlorabspaltung: sie beträgt bei Verwendung von Palladium 4 %, bei unmodifiziertem Platin weniger als 2 % und bei sulfitiertem Platin (hergestellt nach DE-PS 2.105.780) unter 1 %. Uberraschend war, daß der sulfitierte Platinkatalysator, der bisher nur zur katalytischen Reduktion von halogenhaltigen Nitroaromaten zu den entpsrechenden Aminen in neutralem oder schwach saurem Medium geeignet erschien, auch zur Reduktion von o-Nitrochlorbenzol zu 2,2'-Dichlorhydrazobenzol in stark alkalischerIn addition, there is a much lower release of chlorine: it is 4% when using palladium, less than 2% with unmodified platinum and less than 1% with sulfited platinum (manufactured according to DE-PS 2.105.780). It was surprising that the sulfited platinum catalyst, which until now only seemed suitable for the catalytic reduction of halogen-containing nitroaromatics to the corresponding amines in neutral or weakly acidic medium, also for the reduction of o-nitrochlorobenzene to 2,2'-dichlorohydrazobenzene in strongly alkaline
Lösung eingesetzt werden kann. Ein weiterer Vorteil ist, daß z.B. das ß-Hydroxyanthrachinon nach der Reduktion aus der wäßrigen Mutterlauge durch Einstellen eines pH von 3 bis 4 praktisch quantitativ fällbar und ohne Reinigung mehrmals wieder einsatzfähig ist, während das 2-Hydroxy-3-chlor- naphthochinon-(1,4) (entstanden während der Reduktion aus 2,3-Dichlornaphthochinon-(1,4)) durch eine aufwendige Abwasserreinigung beseitigt werden muß.Solution can be used. Another advantage is that e.g. the ß-hydroxyanthraquinone after the reduction from the aqueous mother liquor by setting a pH of 3 to 4 can be precipitated practically quantitatively and can be reused several times without purification, while the 2-hydroxy-3-chloro-naphthoquinone- (1,4) (formed during the reduction from 2,3-dichloronaphthoquinone (1,4)) has to be eliminated by a complex wastewater treatment.
Die Einsatzmenge an Anthrachinonen ist gering, sie liegt unter denen der Naphthochinonderivate. So ist z.B. ein Gewichtsverhältnis ß-Hydroxyanthrachinon zu o-Chlornitrobenzol von 0,003 bis 0,008, insbesondere 0,004 : 1 ausreichend, um auch das als Zwischenstufe auftretende Dichlorazoxybenzol über das Dichlorazobenzol gleichmäßig bis zur Hydrazoverbindung durchzureduzieren, während vom 2,3-Dichlornaphthochinon-(1,4) die doppelte Menge notwendig ist, um wenigstens beim ersten Einsatz der Edelmetallkatalysatoren vergleichbare Ergebnisse zu erzielen.The amount of anthraquinones used is small, it is lower than that of the naphthoquinone derivatives. For example, a weight ratio of ß-hydroxyanthraquinone to o-chloronitrobenzene of 0.003 to 0.008, in particular 0.004: 1 is sufficient to evenly reduce the dichlorazoxybenzene which occurs as an intermediate via the dichlorazobenzene through to the hydrazo compound, while of 2,3-dichloronaphthoquinone- (1,4) twice the amount is necessary in order to achieve comparable results at least when the noble metal catalysts are used for the first time.
Für die Wirtschaftlichkeit des Verfahrens ist von Bedeutung, daß der Edelmetallkatalysator - bei zuverlässiger Reproduzierbarkeit der Ausbeuten und Produkteigenschaften auch nach vielmaligem Einsatz - nur in einem Gewichtsverhältnis von Nitroverbindung zu Platin oder Palladium zwischen etwa 4000: 1 und 1500 : 1, vorzugsweise 2500 : 1, eingesetzt zu werden braucht.For the economics of the process, it is important that the noble metal catalyst - with reliable reproducibility of the yields and product properties even after repeated use - only in a weight ratio of nitro compound to platinum or palladium between about 4000: 1 and 1500: 1, preferably 2500: 1, needs to be used.
Als Reaktionsmedium verwendet man eine 16 bis 25 %ige Natronlauge in der Menge, daß nach Reaktionsende durch das entstandene Reaktionswasser eine 10 bis 15 %ige Natronlaugekonzentration entsteht.A 16 to 25% sodium hydroxide solution is used as the reaction medium in such an amount that, after the reaction has ended, a 10 to 15% sodium hydroxide solution is produced by the water of reaction formed concentration arises.
Auch hier zeigen die Anthrachinone gegenüber den Naphthochinonen Vorteile. Während mit Naphthochinon die besten Ergebnisse mit einer 16 %igen Natronlauge in einem Gewichtsverhältnis o-Nitrochlorbenzol zu NaOH (100 %) wie 1 : 0,095 erzielt werden, erlauben die Anthrachinone eine Erhöhung der NaOH-Konzentration bis auf 25 % und einen geringeren Einsatz von Natronlauge in einem Gewichtsverhältnis von o-Nitrochlorbenzol zu NaOH (100 %) wie 1 : :0,071, ohne daß dabei die Reaktionsgeschwindigkeit verlangsamt wird. Der Einsatz einer ca. 25 %igen NaOH bedeutet gegenüber einer 16 %igen NaOH nach obigen Gewichtsverhältnissen eine Verbesserung der Raumausbeute von ca. 20 %.Again, the anthraquinones show advantages over the naphthoquinones. While the best results are achieved with naphthoquinone with a 16% sodium hydroxide solution in a weight ratio of o-nitrochlorobenzene to NaOH (100%) such as 1: 0.095, the anthraquinones allow an increase in the NaOH concentration up to 25% and a lower use of sodium hydroxide solution in a weight ratio of o-nitrochlorobenzene to NaOH (100%) such as 1:: 0.071, without slowing down the reaction rate. The use of an approx. 25% NaOH means an improvement in the space yield of approx. 20% compared to a 16% NaOH according to the above weight ratios.
Die Reaktionstemperatur liegt bevorzugt zwischen 55 bis 60°C, der Wasserstoffdruck bevorzugt zwischen 1 bis 6 bar, wobei es vorteilhaft ist, den Druck während der Reduktion innerhalb der angegebenen Grenzwerte langsam steigen zu lassen.The reaction temperature is preferably between 55 to 60 ° C., the hydrogen pressure preferably between 1 to 6 bar, it being advantageous to let the pressure rise slowly within the specified limit values during the reduction.
Bei dem erfindungsgemäßen Verfahren wird die Reduktion von o-Nitrochlorbenzol zu 2,2'- . Dichlorohydrazobenzol unter Verwendung eines mit Wasser nicht mischbaren Lösemittels, wie z.B. Benzol, Toluol, Xylol, Äthylbenzol oder deren technische Gemische, beispielsweise das unter dem Namen "Solventnaphtha" handelsübliche Gemisch aus m-Xylol und Äthylbenzol, durchgeführt.In the process according to the invention, the reduction of o-nitrochlorobenzene to 2,2'-. Dichlorohydrazobenzene using a water-immiscible solvent, e.g. Benzene, toluene, xylene, ethylbenzene or their technical mixtures, for example the mixture of m-xylene and ethylbenzene, which is commercially available under the name "Solventnaphtha".
Die Reduktion wird besonders vorteilhaft so vorgenommen, daß man o-Nitrochlorbenzol, wäßrige Natronlauge, das AnthrachinonDerivat, z.B. ß-Hydroxyanthrachinon, Lösemittel, ein Emulgiermittel und einen Edelmetall- katalysator in einen üblichen Autoklaven einfüllt und nach Verdrängen der Luft mit Stickstoff unter Rühren aufheizt. Man ersetzt den Stickstoff durch Wasserstoff und drückt so lange Wasserstoff auf, bis kein Druckabfall mehr erfolgt. Die gewünschte Reaktionstemperatur wird durch Kühlung oder Heizung von außen aufrechterhalten.The reduction is carried out particularly advantageously in such a way that o-nitrochlorobenzene, aqueous sodium hydroxide solution, the anthraquinone derivative, e.g. ß-Hydroxyanthraquinone, solvent, an emulsifier and a noble metal catalyst are filled into a conventional autoclave and, after the air has been displaced, heated with nitrogen while stirring. The nitrogen is replaced by hydrogen and hydrogen is pressed on until there is no more pressure drop. The desired reaction temperature is maintained by external cooling or heating.
Nach Beendigung der Reduktion wird unter Stickstoff der Katalysator abfiltriert und ohne Reinigung in die nächste Reduktionscharge zurückgeführt, wobei er wenigstens zehnaml eingesetzt werden kann.After the end of the reduction, the catalyst is filtered off under nitrogen and returned to the next reduction batch without purification, it being possible to use it at least ten times.
Zur Bestimmung der Ausbeute wird nach Abtrennung der Wasserphase von der Lösemittelphase, in der das gebildete 2,2'-Dichlorhydrazobenzol und o-Chloranilin gelöst sind, mit verdünnter Salzsäure das o-Chloranilin ausgewaschen, das Lösemittel abdestilliert und die Hydrazoverbindung getrocknet. Da das Produkt in ausreichender Reinheit anfällt, kann auch die organische Phase direkt der Umlagerung mit Mineralsäuren zu 3,3'-Dichlorbenzidin zugeführt werden.To determine the yield, after separating the water phase from the solvent phase in which the 2,2'-dichlorohydrazobenzene and o-chloroaniline formed are dissolved, the o-chloroaniline is washed out with dilute hydrochloric acid, the solvent is distilled off and the hydrazo compound is dried. Since the product is obtained in sufficient purity, the organic phase can also be fed directly to the rearrangement with mineral acids to give 3,3'-dichlorobenzidine.
Das erfindungsgemäße Verfahren gestattet es also, 2,2'-Dichlorhydrazobenzol in besonders wirtschaftlicher Weise durch katalytische Reduktion von o-Nitrochlorbenzol in Gegenwart von Anthrachinonen in hohen Ausbeuten und gut reproduzierbar herzustellen. Die Vorteile des erfindungsgemäßen Verfahrens seien an folgenden Beispielen näher erläutert. Die Prozentangaben beziehen sich hierbei auf das Gewicht, sofern nichts anderes angegeben ist.The process according to the invention thus makes it possible to produce 2,2'-dichlorohydrazobenzene in a particularly economical manner by catalytic reduction of o-nitrochlorobenzene in the presence of anthraquinones in high yields and in a reproducible manner. The advantages of the method according to the invention are explained in more detail in the following examples. The percentages relate to the weight, unless stated otherwise.
In einem 2 1-Stahlautoklaven mit Magnethubrührung, Heizvorrichtung und Kühlung werden vorgelegt:
Nach Verdrängen der Luft im verschlossenen Autoklaven mit Stickstoff wird das Reaktionsgemisch unter Rühren auf 60°C erwärmt und Wasserstoff bis auf 3 bar aufgedrückt. Entsprechend der Wasserstoffaufnahme wird der Wasserstoffdruck bis zum Ende der Reduktion bis auf 6 bar gesteigert. Die Reduktion ist beendet, wenn die Aufnahme des Wasserstoffs abbricht, was nach 5 Stunden der Fall ist. Nach Reaktionsende wird die Reaktionsmischung auf 80°C erhitzt und bei dieser Temperatur der Palladium-Kohle-Katalysator abfiltriert. Das Filtrat wird mit 600 ml "Solventnaphtha" verdünnt und die organische Phase, die das 2,2'-Dichlorhydrazobenzol sowie das als Nebenprodukt gebildete o-Chloranilin enthält, von der wäßrigen Phase getrennt.After the air has been displaced in a closed autoclave with nitrogen, the reaction mixture is heated to 60 ° C. with stirring and hydrogen is injected to 3 bar. Depending on the hydrogen uptake, the hydrogen pressure is increased to 6 bar by the end of the reduction. The reduction is complete when the uptake of hydrogen ceases, which is the case after 5 hours. After the end of the reaction, the reaction mixture is heated to 80 ° C. and the palladium-carbon catalyst is filtered off at this temperature. The filtrate is diluted with 600 ml of "solvent naphtha" and the organic phase, which contains the 2,2'-dichlorohydrazobenzene and the o-chloroaniline formed as a by-product, is separated from the aqueous phase.
Zur Bestimmung der Ausbeute wird in üblicher Weise das o-Chloranilin durch zweimaliges Waschen mit 5 %iger Salzsäure herausgelöst und das "Solventnaphtha" im Vakuum entfernt.To determine the yield, the o-chloroaniline is dissolved out in a customary manner by washing twice with 5% hydrochloric acid and the “solvent naphtha” is removed in vacuo.
Die Ausbeute beträgt 84 % d. Th. an 2,2'-Dichlorhydrazobenzol vom Schmelzpunkt 85-86°C sowie 10 % d. Th. an o-Choranilin, jeweils bezogen auf das eingesetzte o-Nitrochorbenzol.The yield is 84% of theory. Th. On 2,2'-dichlorohydrazobenzene with a melting point of 85-86 ° C and 10% of theory. Th. To o-choraniline, each based on the o-nitrochorbenzene used.
Der abfiltrierte Palladium-auf-Kohle-Katalysator wird ohne Reinigung noch mindestens zehnmal eingesetzt und die Reduktion in gleicher Weise durchgeführt. Bei allen Folgeansätzen wird, ohne Minderung der Qualität, die gleiche Ausbeute an 2,2'-Dichlorhydrazobenzol wie beim Startansatz erhalten. Die Reduktionszeit beträgt konstant ca. 5 Stunden.The filtered-off palladium-on-carbon catalyst is used at least ten times without purification and the reduction is carried out in the same way. In all subsequent batches, the same yield of 2,2'-dichlorohydrazobenzene as in the starting batch is obtained without reducing the quality. The reduction time is constantly around 5 hours.
Die Bestimmung der Chlorabspaltung erfolgt in der wäßrigen Phase durch potentiometrische Titration und beträgt bei allen Ansätzen jeweils max. 4 %, bezogen auf o-Nitrochlorbenzol.The chlorine elimination is determined in the aqueous phase by potentiometric titration and is max. 4%, based on o-nitrochlorobenzene.
Es wird has Beispiel 1 wiederholt, jedoch wird an Stelle des Hydroxyanthrachinon 5 g 2,3-Dichlornaphthochinon-(1,4) eingesetzt. Nach Erreichen der Azoxystufe bricht die Reaktion bei einer Reaktionstemperatur von 60°C ab und kann nuf durch Steigerung der Reaktionstemperatur auf 80°C zu Ende geführt werden. Die Ausbeute beträgt 80 % d.Th., bezogen auf o-Nitrochlorbenzol. Die Reduktion dauert 6,25 Stunden.Example 1 is repeated, but 5 g of 2,3-dichloronaphthoquinone- (1,4) is used instead of the hydroxyanthraquinone. After reaching the azoxy stage, the reaction stops at a reaction temperature of 60 ° C and can now be completed by increasing the reaction temperature to 80 ° C. The yield is 80% of theory, based on o-nitrochlorobenzene. The reduction takes 6.25 hours.
Bei Wiedereinsatz des Palladium-Katalysators sinkt die Ausbeute gleichmäßig ab und liegt z.B. nach viermaliger Rückführung nur noch bei 76 % d.Th., während die Reduktionszeit auf 8 Studen ansteigt. Die Chlorabspaltung beträgt 8 %, bezogen auf o-Nitrochlorbenzol.When the palladium catalyst is used again, the yield drops evenly and is e.g. after four recirculation only at 76% of theory, while the reduction time increases to 8 hours. The elimination of chlorine is 8%, based on o-nitrochlorobenzene.
Die Ausbeute beträgt 83 % d.Th. an 2,2'-Dichlorhydrazobenzol, bezogen auf o-Nitrochlorbenzol, mit einem Schmelzpunkt von 84 bis 86°C, die Reaktionszeit beträgt 5 Stunden. Nach zehnmaliger Rückführung des Platinkatalysators sind die Ausbeuten und die Reaktionszeiten konstant. Die Chlorabspaltung beträgt max. 1,7 % d.Th., bezogen auf o-Nitrochlorbenzol.The yield is 83% of theory of 2,2'-dichlorohydrazobenzene, based on o-nitrochlorobenzene, with a melting point of 84 to 86 ° C, the reaction time is 5 hours. After recycling the platinum catalyst ten times, the yields and the reaction times are constant. The release of chlorine is max. 1.7% of theory, based on o-nitrochlorobenzene.
Es wird entsprechend Beispiel 1 verfahren, jedoch an Stelle des Palladium-Katalysators 0,25 g Platin, in Form von 10 g sulfitiertem 5 % Platin-auf-Kohlenstoff-Katalysator mit 50 % Wassergehalt (entsprechend DE-PS 2.105.780), eingesetzt. Die Ausbeute beträgt 83 96 d.Th. an 2,2-Dichlorhydrazobenzol, bezogen auf o-Nitrochlorbenzol, mit einem Schmelzpunkt von 85 bis 86°C, die Reaktionszeit beträgt 5 Stunden. Nach zehnmaliger Rückführung des Platinkatalysators waren die Ausbeuten und die Reaktionszeiten konstant. Die Chlorabspaltung beträgt max. 0,7 % d.Th., bezogen auf o-Nitrochlorbenzol.The procedure is as in Example 1, but instead of the palladium catalyst 0.25 g of platinum, in the form of 10 g of sulfited 5% platinum-on-carbon catalyst with 50% water content (corresponding to DE-PS 2.105.780) . The yield is 83 96 th. of 2,2-dichlorohydrazobenzene, based on o-nitrochlorobenzene, with a melting point of 85 to 86 ° C, the reaction time is 5 hours. After recycling the platinum catalyst ten times, the yields and the reaction times were constant. The release of chlorine is max. 0.7% of theory, based on o-nitrochlorobenzene.
Claims (6)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2733747A DE2733747C2 (en) | 1977-07-27 | 1977-07-27 | Process for the preparation of 2,2 dichlorohydrazobenzene |
| DE2733747 | 1977-07-27 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0000519A1 EP0000519A1 (en) | 1979-02-07 |
| EP0000519B1 true EP0000519B1 (en) | 1980-07-23 |
Family
ID=6014887
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP78100394A Expired EP0000519B1 (en) | 1977-07-27 | 1978-07-14 | Process for the preparation of 2,2'-dichlorohydrazobenzene |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4217307A (en) |
| EP (1) | EP0000519B1 (en) |
| JP (1) | JPS5424838A (en) |
| CA (1) | CA1111449A (en) |
| DE (2) | DE2733747C2 (en) |
| IT (1) | IT1097303B (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2833605A1 (en) * | 1978-07-31 | 1980-02-14 | Dynamit Nobel Ag | METHOD FOR PRODUCING HYDRAZOBENZOLS BY CATALYTIC HYDRATION OF NITROBENZOLES |
| US4375559A (en) * | 1982-07-15 | 1983-03-01 | Air Products And Chemicals, Inc. | Process for the production of hydrazoaromatics using a multi-phase system |
| US5808154A (en) * | 1989-04-05 | 1998-09-15 | Toyo Ink Manufacturing Co., Ltd. | Process for the production of an aromatic hydrazo compound |
| JPH0699380B2 (en) * | 1989-04-05 | 1994-12-07 | 東洋インキ製造株式会社 | Method for producing aromatic hydrazo compound |
| US20050037063A1 (en) * | 2003-07-21 | 2005-02-17 | Bolton Anthony E. | Combined therapies |
| ATE439347T1 (en) * | 2004-11-23 | 2009-08-15 | Warner Lambert Co | 7-(2H-PYRAZOLE-3-YL)-3,5-DIHYDROXY-HEPTANIC ACID DERIVATIVES AS HMG-CO-A-REDUCTASE INHIBITORS FOR THE TREATMENT OF LIPIDEMIA |
| JP2006265129A (en) * | 2005-03-23 | 2006-10-05 | Air Water Inc | Method for producing 3,3'-bis(trifluoromethyl)hydrazobenzene |
| GT200600381A (en) | 2005-08-25 | 2007-03-28 | ORGANIC COMPOUNDS | |
| US7741317B2 (en) | 2005-10-21 | 2010-06-22 | Bristol-Myers Squibb Company | LXR modulators |
| US7888376B2 (en) | 2005-11-23 | 2011-02-15 | Bristol-Myers Squibb Company | Heterocyclic CETP inhibitors |
| US8383660B2 (en) | 2006-03-10 | 2013-02-26 | Pfizer Inc. | Dibenzyl amine compounds and derivatives |
| US7919506B2 (en) | 2006-03-10 | 2011-04-05 | Pfizer Inc. | Dibenzyl amine compounds and derivatives |
| ATE547394T1 (en) | 2006-12-01 | 2012-03-15 | Bristol Myers Squibb Co | N-((3-BENZYL)-2,2-(BIS-PHENYL)-PROPANE-1- AMINE DERIVATIVES AS CETP INHIBITORS FOR THE TREATMENT OF ATHEROSCLERosis AND CARDIOVASCULAR DISEASES |
| SG11201507496UA (en) | 2013-04-17 | 2015-11-27 | Pfizer | N-piperidin-3-ylbenzamide derivatives for treating cardiovascular diseases |
| WO2016055901A1 (en) | 2014-10-08 | 2016-04-14 | Pfizer Inc. | Substituted amide compounds |
| SG11202107614PA (en) | 2019-01-18 | 2021-08-30 | Astrazeneca Ab | Pcsk9 inhibitors and methods of use thereof |
| CN111116407B (en) * | 2019-12-16 | 2022-02-22 | 浙江秦燕科技股份有限公司 | Method for preparing DCB reducing substance by continuous catalytic hydrogenation reduction |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2794046A (en) * | 1954-08-06 | 1957-05-28 | Allied Chem & Dye Corp | Method of reducing aromatic nitrogen compounds |
| US3156724A (en) * | 1962-10-25 | 1964-11-10 | Sterling Drug Inc | Preparation of 2, 2'-dichlorohydrazobenzene |
| NL131211C (en) * | 1965-04-05 |
-
1977
- 1977-07-27 DE DE2733747A patent/DE2733747C2/en not_active Expired
-
1978
- 1978-07-14 EP EP78100394A patent/EP0000519B1/en not_active Expired
- 1978-07-14 DE DE7878100394T patent/DE2860060D1/en not_active Expired
- 1978-07-25 US US05/927,856 patent/US4217307A/en not_active Expired - Lifetime
- 1978-07-25 IT IT26090/78A patent/IT1097303B/en active
- 1978-07-26 CA CA308,185A patent/CA1111449A/en not_active Expired
- 1978-07-26 JP JP9056478A patent/JPS5424838A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS627908B2 (en) | 1987-02-19 |
| DE2733747B1 (en) | 1979-02-08 |
| IT1097303B (en) | 1985-08-31 |
| DE2733747C2 (en) | 1979-09-27 |
| CA1111449A (en) | 1981-10-27 |
| JPS5424838A (en) | 1979-02-24 |
| IT7826090A0 (en) | 1978-07-25 |
| DE2860060D1 (en) | 1980-11-13 |
| EP0000519A1 (en) | 1979-02-07 |
| US4217307A (en) | 1980-08-12 |
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