CA1171850A - Process for the manufacture of 1,3-diaryl triazenes - Google Patents
Process for the manufacture of 1,3-diaryl triazenesInfo
- Publication number
- CA1171850A CA1171850A CA000408799A CA408799A CA1171850A CA 1171850 A CA1171850 A CA 1171850A CA 000408799 A CA000408799 A CA 000408799A CA 408799 A CA408799 A CA 408799A CA 1171850 A CA1171850 A CA 1171850A
- Authority
- CA
- Canada
- Prior art keywords
- acid
- nitrite
- temperature
- primary aromatic
- aniline
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/60—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D213/72—Nitrogen atoms
- C07D213/76—Nitrogen atoms to which a second hetero atom is attached
- C07D213/77—Hydrazine radicals
Abstract
Abstract of the disclosure:
1,3-Diaryl triazenes are prepared by reacting gaseous alkyl nitrites with primary aromatic monoamines in a liquid phase containing preferably a polar protic solvent, in the presence of a small quantity of an acid.
The reaction products are partially final products, for example suitable for use as foamers in the plastics manufacture, partially intermediates suitable for use in various fields, for example the fields of polymers, dyestuffs and pharmaceuticals.
1,3-Diaryl triazenes are prepared by reacting gaseous alkyl nitrites with primary aromatic monoamines in a liquid phase containing preferably a polar protic solvent, in the presence of a small quantity of an acid.
The reaction products are partially final products, for example suitable for use as foamers in the plastics manufacture, partially intermediates suitable for use in various fields, for example the fields of polymers, dyestuffs and pharmaceuticals.
Description
' 171~50
- 2 - I~OE ~l/F 191 1,3-Diaryl triazenes are compounds o~ the formula Ar-N=N-NH-Ar, wherein Ar is optionally substituted aryl.
They are used as such, ~or example as foamers in the manufacture of plastics, mainly, however, as inter-mediates, in particular in the manufacture of aromatic diamines and of arylhydrazines (in particular phenyl-hydrazine), which latter are processed in known mannerto yield corresponding final products, mainly in the field of polymers, dyestuffs and pharmaceuticals.
The 1,3-diaryl triazenes rearrange to form the corresponding aminoazo compounds by heating and/or by the action of acids. According to the process of European Offenlegungsschrift 13 6l~3 this rearrangement is conducted by using from about 0.4 to 2.0 weight %, referred to the triazene-contain.ing solution, of a strong acid, in particular nitric acid.
A number of processe3 for the rr.anufacture of 1,3-diaryl triazenes are known. One method is described, by way of example, by G. Vernin et al. in Synthe~i~
1977, pages 691-693. This method consists in reaoting i-amyl nitrite with primary aromatic monoamines at room temperature in non-polar aprotic solvents (such as hexane, petrol ether and the like). According to said reference, triazene is said to be obtained in a high yield in short reaction periods.
According to the sole example for the Lanufacture of a triazene ~ 1,3-bis-(3,5-dichlorophenyl)-triazene of said reference which comprise~ reacting i-amyl nltrite with 3,5-dichloroaniline at room temperature in petroi ether/benzene on a laboratory scale the de~ired product is said to be obtained in a yield of 90 ~ within 30 minutes i-Amylnltrite was used, - ' 171850
They are used as such, ~or example as foamers in the manufacture of plastics, mainly, however, as inter-mediates, in particular in the manufacture of aromatic diamines and of arylhydrazines (in particular phenyl-hydrazine), which latter are processed in known mannerto yield corresponding final products, mainly in the field of polymers, dyestuffs and pharmaceuticals.
The 1,3-diaryl triazenes rearrange to form the corresponding aminoazo compounds by heating and/or by the action of acids. According to the process of European Offenlegungsschrift 13 6l~3 this rearrangement is conducted by using from about 0.4 to 2.0 weight %, referred to the triazene-contain.ing solution, of a strong acid, in particular nitric acid.
A number of processe3 for the rr.anufacture of 1,3-diaryl triazenes are known. One method is described, by way of example, by G. Vernin et al. in Synthe~i~
1977, pages 691-693. This method consists in reaoting i-amyl nitrite with primary aromatic monoamines at room temperature in non-polar aprotic solvents (such as hexane, petrol ether and the like). According to said reference, triazene is said to be obtained in a high yield in short reaction periods.
According to the sole example for the Lanufacture of a triazene ~ 1,3-bis-(3,5-dichlorophenyl)-triazene of said reference which comprise~ reacting i-amyl nltrite with 3,5-dichloroaniline at room temperature in petroi ether/benzene on a laboratory scale the de~ired product is said to be obtained in a yield of 90 ~ within 30 minutes i-Amylnltrite was used, - ' 171850
- 3 - HOE 81/F 191 however, in considerable excess (the 3-fold quantity).
The reaction batch was worked up by evaporation on a rotary evaporator, suction-filtering of the residual solid, washing out and drying.
This method is not advantageous for the industrial-scale manufacture mainly because of the great excess of i-amyl nitrite employed and because of the evaporation of the reaction batch on the rotary evaporator. Said reference does not specify whether evaporation has been carried out in vacuum or under normal pressure. As the water jet vacuum is the vacuum commonly employed for such cases, it cannot be avoided, unless particular possibly complicated measures have been taken, that part of the relatively easily volatile solvent is entrained with the current of water and passes into the waste water, which should be avoided for reasons of environmen-tal protection, in any case, with relatively great batche~. Evaporation in vacuum could be conducted, however, at least without an increase in temperature.
Evaporation under normal pressure, however, requires a temperature increase, which ~urely is harmless for some 1,3-diaryl triazenes, which are rather stable owing to very defined substituents. Other 1,3-diaryl-triazenes, which constitute the great majority of the normal 1,3-diaryl triazenes, are easily subject to a rearrange-ment, because of their relative instability at elevated temperature, or are decomposed in other manner, which is a considerable disadvantage.
According to G.Vernin et al.,the reaction of i-amyl nitrite with primary aromatic monoamines at room tempe-rature can be carried out as well at room temperature in polar protic solvents (methanol~), if a mercury salt such as Hg(OCOCH3)2 is added. However, thls reaction does not result in the free l,3-triazene, but in the corresponding Hg-complex. Nothing is disclosed in ~aid reference above the ralease of the triazene from the complex.
! 171850
The reaction batch was worked up by evaporation on a rotary evaporator, suction-filtering of the residual solid, washing out and drying.
This method is not advantageous for the industrial-scale manufacture mainly because of the great excess of i-amyl nitrite employed and because of the evaporation of the reaction batch on the rotary evaporator. Said reference does not specify whether evaporation has been carried out in vacuum or under normal pressure. As the water jet vacuum is the vacuum commonly employed for such cases, it cannot be avoided, unless particular possibly complicated measures have been taken, that part of the relatively easily volatile solvent is entrained with the current of water and passes into the waste water, which should be avoided for reasons of environmen-tal protection, in any case, with relatively great batche~. Evaporation in vacuum could be conducted, however, at least without an increase in temperature.
Evaporation under normal pressure, however, requires a temperature increase, which ~urely is harmless for some 1,3-diaryl triazenes, which are rather stable owing to very defined substituents. Other 1,3-diaryl-triazenes, which constitute the great majority of the normal 1,3-diaryl triazenes, are easily subject to a rearrange-ment, because of their relative instability at elevated temperature, or are decomposed in other manner, which is a considerable disadvantage.
According to G.Vernin et al.,the reaction of i-amyl nitrite with primary aromatic monoamines at room tempe-rature can be carried out as well at room temperature in polar protic solvents (methanol~), if a mercury salt such as Hg(OCOCH3)2 is added. However, thls reaction does not result in the free l,3-triazene, but in the corresponding Hg-complex. Nothing is disclosed in ~aid reference above the ralease of the triazene from the complex.
! 171850
- 4 - HOE 81/F 191 If the mercury salt is o~itted, the reaction of the alkyl nitrite and the primary aromatic monoamine does take place at room temperature in methanol, only after a considerable period o~ induction (of several hours (as tests of the Applicant have shown).
Attempts to improve the process published by G. Vernin et al. in a manner appropriate also for large-scale conditions have shown that this object is reached mainly by using gaseous alkyl nitrites and by adding a small quantity of acid to the primary aromatic monoamine, advantageously dissolved in a polar protic solvent.
Subject of the present invention, consequently, is a process for the manufacture of 1,3-diaryl triazenes by reacting alkyl nitrites with primary aromatic mono-amines at room temperature or at a temperature slightly above room temperature, which comprises introducing alkyl nitrites gaseous at the temperature applied into primary aromatic monoamirJeq liquid at the temperature applied or dissolved in a polar protic solvent, in the presence of a small quantity of acid.
This prooes~ gives triazene in a high yield.
An alkyl nitrite excess is not required and possible induction times (for example as in the oase of the reaction proceeding without the addition of an acid) are not observed. The reaction batch can be worked up by precipitation of the triazenes with water because of the hydrophilic character of the polar protic solvents, in particular the low-molecular alcohols preferably used in this case. Thus solvents do not pass into the waste water (as in the method according to G.Vernin et al. wherein the solvent is withdrawn by a water jet vacuum) and the reaction products are not subjected to a ternperature strain (as in the process of G.~/ernin, if the solvent is withdrawn under normal pressure and, - ! l 7185~
Attempts to improve the process published by G. Vernin et al. in a manner appropriate also for large-scale conditions have shown that this object is reached mainly by using gaseous alkyl nitrites and by adding a small quantity of acid to the primary aromatic monoamine, advantageously dissolved in a polar protic solvent.
Subject of the present invention, consequently, is a process for the manufacture of 1,3-diaryl triazenes by reacting alkyl nitrites with primary aromatic mono-amines at room temperature or at a temperature slightly above room temperature, which comprises introducing alkyl nitrites gaseous at the temperature applied into primary aromatic monoamirJeq liquid at the temperature applied or dissolved in a polar protic solvent, in the presence of a small quantity of acid.
This prooes~ gives triazene in a high yield.
An alkyl nitrite excess is not required and possible induction times (for example as in the oase of the reaction proceeding without the addition of an acid) are not observed. The reaction batch can be worked up by precipitation of the triazenes with water because of the hydrophilic character of the polar protic solvents, in particular the low-molecular alcohols preferably used in this case. Thus solvents do not pass into the waste water (as in the method according to G.Vernin et al. wherein the solvent is withdrawn by a water jet vacuum) and the reaction products are not subjected to a ternperature strain (as in the process of G.~/ernin, if the solvent is withdrawn under normal pressure and, - ! l 7185~
- 5 - HOE 81/F 191 as a consequenoe thereof, at elevated temperature). The proceQs is therefore excellently suitable for the large-scale manufacture.
It was extremely surprising that the presence or addition of a small quantity of acid has a catalytic effect on the desired reaction without provoking simultaneously to an undesired great extent the rearrange-ment of the 1,3-diaryl triazenes giving the corresponding p-aminoazobenzenes, which reaction, as is known, is catalyzed by acids. This surpri~ing reaction course i~
probably caused at least partially by other conditions of the process of the invention (use of gaseous alkyl nitrites, preferably use of polar protic solvents).
Suitable alkyl nitrites that are gaseous at room temperature or at a temperature slightly higher than romm temperature are preferably methyl nitrite CH3NO2 and/or ethyl nitrite C2H5NO2. They may be ohtained~
~or example, according to the process described in German patent 1,156,77~ from N2O3 or nitrose gclSeS
(= mixtures consisting mainly of NO and NO2) and alcohols. The procedure i~ advantageously as follows: A
mlxture Or NO, NO2 and nitrogen in an alcohol, preferably methanol or ethanol, is in~ected into a corresponding reactor ~where effective mixing of the gas and liquid takes place). The molar ratio of NO and ~2 in the mixture of nitrose gases may be from about 100:1 to about 40:60, preferably it is about 1:1, the portion of inert gas may be from O to about 99 ~. This gaseou~
mixture may be readily obtained by oxidizing NO with air or with pure oxygen. A technical mixture of nitrose gases, as obtained in the nitric acid production, may likewi~e be used.
The alkyl nitrite reactor is operated at a tempera-t.ure which i8 chosen such that the alkyl nitrite formed is withdrawn from the reaction mixture in ga~eous .~tate. The methyl nitrite and ethyl nitrite (bo~ling ~ 171~50
It was extremely surprising that the presence or addition of a small quantity of acid has a catalytic effect on the desired reaction without provoking simultaneously to an undesired great extent the rearrange-ment of the 1,3-diaryl triazenes giving the corresponding p-aminoazobenzenes, which reaction, as is known, is catalyzed by acids. This surpri~ing reaction course i~
probably caused at least partially by other conditions of the process of the invention (use of gaseous alkyl nitrites, preferably use of polar protic solvents).
Suitable alkyl nitrites that are gaseous at room temperature or at a temperature slightly higher than romm temperature are preferably methyl nitrite CH3NO2 and/or ethyl nitrite C2H5NO2. They may be ohtained~
~or example, according to the process described in German patent 1,156,77~ from N2O3 or nitrose gclSeS
(= mixtures consisting mainly of NO and NO2) and alcohols. The procedure i~ advantageously as follows: A
mlxture Or NO, NO2 and nitrogen in an alcohol, preferably methanol or ethanol, is in~ected into a corresponding reactor ~where effective mixing of the gas and liquid takes place). The molar ratio of NO and ~2 in the mixture of nitrose gases may be from about 100:1 to about 40:60, preferably it is about 1:1, the portion of inert gas may be from O to about 99 ~. This gaseou~
mixture may be readily obtained by oxidizing NO with air or with pure oxygen. A technical mixture of nitrose gases, as obtained in the nitric acid production, may likewi~e be used.
The alkyl nitrite reactor is operated at a tempera-t.ure which i8 chosen such that the alkyl nitrite formed is withdrawn from the reaction mixture in ga~eous .~tate. The methyl nitrite and ethyl nitrite (bo~ling ~ 171~50
- 6 - HOE ~1 /F 191 points -12C and 16C respectively3 may even be discharged with the inert gas current without further expenditure at normal temperature, the gas current passing advantageous]y via a condenser in order to avoid that an excessive quant ty of alcohol is entrained.
The quantity of alkyl nitrite is determined simply by the quantity of nitrose gases injected. In a preferred embodiment of the invention the alkyl nitrite thus prepared is introduced into the primary aromatic mono-amine in a further recipient connected i3nmediately withthe alkyl nitrite reactor said monoamine being present as such in liquid form or, preferably, dissolved in a polar protic solvent and containing a small quantity of acid.
Suitable primary aromatic monoamines are on principle any amines, the amines liquid at room temperature or at a temperature slightly above room temperature being used a.s sucn or in dissolved form and the solid amines being used only in dissolved form. Preference .is given to the primary aromatic monoamines corresponding to the following formula R3 ~ ~ 1 wherein R1, R2 and R3 independent from each other denote H, halogen (F, Cl, Br, J), alkyl (preferably C1-C4 alkyl) and N02, in particular only H.
Examples of suitable monoam~nes of thi~ type are:
! 171850
The quantity of alkyl nitrite is determined simply by the quantity of nitrose gases injected. In a preferred embodiment of the invention the alkyl nitrite thus prepared is introduced into the primary aromatic mono-amine in a further recipient connected i3nmediately withthe alkyl nitrite reactor said monoamine being present as such in liquid form or, preferably, dissolved in a polar protic solvent and containing a small quantity of acid.
Suitable primary aromatic monoamines are on principle any amines, the amines liquid at room temperature or at a temperature slightly above room temperature being used a.s sucn or in dissolved form and the solid amines being used only in dissolved form. Preference .is given to the primary aromatic monoamines corresponding to the following formula R3 ~ ~ 1 wherein R1, R2 and R3 independent from each other denote H, halogen (F, Cl, Br, J), alkyl (preferably C1-C4 alkyl) and N02, in particular only H.
Examples of suitable monoam~nes of thi~ type are:
! 171850
- 7 - HOE 81/F 191 .
~ 21~3C~I~H2 <~UH2 F ~-- N~lCl ~--NE72 ~ N~2 and the like.
1'he reaction temperature may range in general from about tO to 50C, prcferably, it is from about 20 to 35C.
Suita~le polar protic 30lvents are on principle all liquids covered by this designation, which do not react themselves under the reaction conditions. Preferred polar protic solvents are C1-C4 alcohols, in particu-lar the aloohols on which the alkyl nitrite used is based, in the first place, consequent].y, methanol and ethanol.
The ratio of polar protic solvent to primary aromatic monoamine may vary within wide limits. It ranges generally from about 5:95 to about 90:10 (weight ratio of polar protic solvent:amine).
Suitable acids added or to be added to the amines are pratically any organic and inorganic weak and strong acids. Mineral acids, in particular hydrochloric acid, are used preferably.
t 17t850
~ 21~3C~I~H2 <~UH2 F ~-- N~lCl ~--NE72 ~ N~2 and the like.
1'he reaction temperature may range in general from about tO to 50C, prcferably, it is from about 20 to 35C.
Suita~le polar protic 30lvents are on principle all liquids covered by this designation, which do not react themselves under the reaction conditions. Preferred polar protic solvents are C1-C4 alcohols, in particu-lar the aloohols on which the alkyl nitrite used is based, in the first place, consequent].y, methanol and ethanol.
The ratio of polar protic solvent to primary aromatic monoamine may vary within wide limits. It ranges generally from about 5:95 to about 90:10 (weight ratio of polar protic solvent:amine).
Suitable acids added or to be added to the amines are pratically any organic and inorganic weak and strong acids. Mineral acids, in particular hydrochloric acid, are used preferably.
t 17t850
- 8 - HOE ~1/F 151 The quantity of acid may range in general from about 0.01 to 5, preferably from about 0.05 to 1, equivalent ~ per mol of primary aromatic monoamine.
This signifies that from about 0.01 to 5, pre~erably from about 0.05 to 1, rnol % of a monobasic acid, half of this quantity of a bibasic acid, a third of this quantity of a tribasic acid and so on, each time per mol of primary aromatic monoamine, is added. ~hen relatively great quantities of acid are added, the undesired rearrangement of the 1,3-triazenes formed yielding mainly the corresponding p-aminoazobenzenes takes place to an increasing degree.
The process of the invention yields the desired triazene in most cases in the form of a crystal sus-pension, which may be further used in very definedcases without isolation of the triazene, for example, if a reduction yieldig phenylhydrazine or a rearrangement yielding p-phenylene diamine is aimed at.
If an isolation of the triazenes is dssired, this may be done advantageously by suction-filtration or similar methods of the product solution from the reactor and addition of water. In this case the triazenes are obtained as yellow- to brownish-colored arystals, which may be suction-filteed. The triazenes are not sub~ect to a particular temperature strain in this isolation method (this method being not applicable to the proce~s of G. Vernin et al., loc. cit., where water i9 used together with irnmisible non-polar aprotic 301vents). The mother liquor and the filtrate may be worked up in a step independent from the triazene production in little-polluting manner.
The yield~ obtained in the process of the invention equal that obtained in the process of G. Vernin, loc.
cit.. The velocity of the formation of triazenes depends naturally, partly to a considerable extent, on the .. . .... . .
~ 171850
This signifies that from about 0.01 to 5, pre~erably from about 0.05 to 1, rnol % of a monobasic acid, half of this quantity of a bibasic acid, a third of this quantity of a tribasic acid and so on, each time per mol of primary aromatic monoamine, is added. ~hen relatively great quantities of acid are added, the undesired rearrangement of the 1,3-triazenes formed yielding mainly the corresponding p-aminoazobenzenes takes place to an increasing degree.
The process of the invention yields the desired triazene in most cases in the form of a crystal sus-pension, which may be further used in very definedcases without isolation of the triazene, for example, if a reduction yieldig phenylhydrazine or a rearrangement yielding p-phenylene diamine is aimed at.
If an isolation of the triazenes is dssired, this may be done advantageously by suction-filtration or similar methods of the product solution from the reactor and addition of water. In this case the triazenes are obtained as yellow- to brownish-colored arystals, which may be suction-filteed. The triazenes are not sub~ect to a particular temperature strain in this isolation method (this method being not applicable to the proce~s of G. Vernin et al., loc. cit., where water i9 used together with irnmisible non-polar aprotic 301vents). The mother liquor and the filtrate may be worked up in a step independent from the triazene production in little-polluting manner.
The yield~ obtained in the process of the invention equal that obtained in the process of G. Vernin, loc.
cit.. The velocity of the formation of triazenes depends naturally, partly to a considerable extent, on the .. . .... . .
~ 171850
- 9 '- HOE 81/F 191 nature of the substituents at the aromatic nucleus of the starting compounds. Electron-accepting substituents decelerate the reaction, whereas electron-releasing substituents accelerate the reaction.
The invention constitutes a considerable progress, ~ince the process can be carried out on an industrial scale in simple,'little-polluting and product-preserving manner.
The invention is illustrated by the following examples. Part of the examples have not been caried out until the complete conversion of the primary aromatlc monoamine used a starting compound. The invention examples are followed by a comparative example, which demonstrates that a reaction does not take place practi-cally, in any case within 2 and a half hours between the gaseous alkyl nitrite (methyl nitrite) and primary aromatic monoamine (aniline) in the presence of a polar protic solvent (methanol), however, in the absence of an acid.
E x z m p l e A mixture of NO and N02 (1:1) produced from 2.7 l/h of NO and 3.6 l/h of air was passed through methanol at room temperature and converted to methyl nitrite.
The methyl nltrite formed was introduced continuously, into a mixture of 100 g of aniline, 0.25 g (0.25 %) of aniline hydrochloride and 5 ml of methanol. The temperature of the reaction mixture rai~e to 33-34C
during the reaction and solid triazene precipi~ated after 95 minutes. The introduction of ga~ was stopped after 110 minutes and the reaction mixture was stirred for 1.5 hours. During this period of time, 2.5 g of methyl ni.trite had passed the qolutionn ln unreacted state and were collected in a cooling trap at -78C.
The reaction mixture was introduced into 500 ml of water, the crystals were suction-filtered and dried.
There were obtained 35.1 g OL slightly-yellow triazene (99.3 %, referred to NO; 33.3 % referred to aniline).
.
~ t 71 850
The invention constitutes a considerable progress, ~ince the process can be carried out on an industrial scale in simple,'little-polluting and product-preserving manner.
The invention is illustrated by the following examples. Part of the examples have not been caried out until the complete conversion of the primary aromatlc monoamine used a starting compound. The invention examples are followed by a comparative example, which demonstrates that a reaction does not take place practi-cally, in any case within 2 and a half hours between the gaseous alkyl nitrite (methyl nitrite) and primary aromatic monoamine (aniline) in the presence of a polar protic solvent (methanol), however, in the absence of an acid.
E x z m p l e A mixture of NO and N02 (1:1) produced from 2.7 l/h of NO and 3.6 l/h of air was passed through methanol at room temperature and converted to methyl nitrite.
The methyl nltrite formed was introduced continuously, into a mixture of 100 g of aniline, 0.25 g (0.25 %) of aniline hydrochloride and 5 ml of methanol. The temperature of the reaction mixture rai~e to 33-34C
during the reaction and solid triazene precipi~ated after 95 minutes. The introduction of ga~ was stopped after 110 minutes and the reaction mixture was stirred for 1.5 hours. During this period of time, 2.5 g of methyl ni.trite had passed the qolutionn ln unreacted state and were collected in a cooling trap at -78C.
The reaction mixture was introduced into 500 ml of water, the crystals were suction-filtered and dried.
There were obtained 35.1 g OL slightly-yellow triazene (99.3 %, referred to NO; 33.3 % referred to aniline).
.
~ t 71 850
- 10 - HOE 81/F 191 GC~an21ysis:
0.32 ~ of aniline, 98.47 % of 1,3-diphenyl triazene, 0.78 ~ of 4-aminoazoben7ene, 0.43 % of 5 unknown components.
E x a m p 1 e 2 The procedure was analogous to that of Example 1, except that 1 % of aniline hydrochloride used as the catalyst gave 34.3 e of 1,3-diphenyl triazene (97.0 ~, referred to N0, 32.4 %, referred to aniline).
GC-analysis:
2.39 % of aniline, 0.16 ~ of 2-aminobiphenyl, 0.30 % of N,N-diphenylamine, 0.19 ~ of 4-amino-biphenyl, 2.70 % of 4-aminoazobenzene, 1.34 % of 8 unknown components.
E x a m p 1 e 3 Proceeding in the manner described in Example 1, a methyl nitrite current was introduced into a mixture of 80 g of aniline, 4 g of aniline hydrochloride (5 %
referred to aniline) and 20 ml of methanol. 33.8 g of product (95.5 %, referred to N0; 31.8 % referred to aniline), were obtained.
GC-analy~is:
0.18 % of 2-amino-biphenyl, 0.44 % of N,N-diphenylamine, 0.22 % of 4-amir.o-biphenyl, 79.62 % of 1,3-diphenyl triazene, 16.97 % of 4-aminoazobenzene, 2.57 ~ of 10 unknown components.
E x a m p 1 e 4 __ When proceeding analogously to Example 1, using, however, in.stead of methanol, ethano', an ethyl nitrite discharge was not observed and 42.0 g of 1,3-diphenyl tria~ene were obtained (97 %s referred to N0; 39.5 %
referred to aniline).
- - - . ,.. ~ .... .. .... ..... . .. . . .
, .
~ 1 71~0 ~ HOE 81/F 191 E x a m p l e 5 The procedure was analogou~ to that of Example 1, using, however, instead of methanol, isopropanol and heating the first reactor at 55C to separate the nitrous acid ester by distillation. There were obtained 41.2 g of 1,3--diphenyl triazene (94.5 % referred to NO;
38.7 ~ referred to aniline~.
~C-analysis:
0.1 % of aniline, 98.0 % of 1,3-diphenyl triazene, 0.2 % of 4-aminoazobenzene, 1.7 % of 13 unknown components.
E x a m p l e 6 Methyl nitrite (from 8.1 l/h of NO; 10.8 l/h of air and methanol) wa~ introduced into a mixture of 1,000 g of aniline, 1 g of aniline hydroehloride (= 0.1 %
referred to aniline) and 50 ml of methanol placed in a circulation reactor of 2 liters content, in the manner descri.bed in Rxample 1, thus heating the reactor contents to a temperature of 33-35C. Solid triazene precipitated after 3 hours. Half of the reaction mixture was passed to a corresponding reactor of the same s.ize and the contents of both reactors were diluted each with liter of methanol so as to form an ea~ily stirrable mixture. Methyl nitrite (from 8.1 l/h of NO; 10.8 l/h of air and methanol) was introduced into each of both reactors for a further 3.5 hours. The resultant yellow ~uspension was 3tirred for 2 hours and withdrawn in vacuo from the apparatus. Triazene was precipitated in a receptable with water. There were obtained 710 g (99.5 %
referred to NO; 67.2 % referred to aniline) Or slightly yellow 1.4 diphenyl triazene.
GC-analy~is:
0.11 % of aniline, 0.04 % of 4 aminobiphenyl, ~ ~7~8~0 - 12 - HOE 81_E` 191 99.54 ~ of 1,4-diphenyl triazene, 0.02 % of 4-aminoazobenzene, 0.25 ~ of 1 unknown component.
E x a m p l e 7 In a manner analogous to Example 6, mQthyl nitrite (from 8.1 l/h of NO; 10.8 l/h of air and methanol) was introduced into a mixture of 800 g of aniline, 1 g of aniline nydrocbloride and 50 ml of methanol. After halving and diluting the contents, methyl nitrite was injected into both reactors for 4 hours each and the batches were allowed to stand overnight to complete their reaction. There were obtained 820 g (100 % referred to NO; 96.6 p referred to aniline) of yellow triazene.
GC-analy~is.
0.71 % of aniline, o.38 ~ of N,N-diphenyl amine, 0.09 % of 4-aminobiphenyl, 93.56 % of 1,3-diphenyl triazene, 4.27 % of 4-aminoazobenzene, 0.98 % of 6 unknown components.
E x a rn p l e 8 In a manner analogous to Example 6, methyl nitrite waA introduced into a mixture Or 500 g of aniline, 0.5 g of aniline hydrochloride and 20 rnl of rnethanol. Methyl nitrite had been produced by passing a technical nitrose mixture (11 % of nitrose, degree of oxidation 33 ~, 38 l/h) through methanol. The gas current wa~ switched off after 6 hours, the mixture was stirred for one hour, triazene was preciitated with water, suction-filtered and dried. 148 g of slightly yellow crystals (99 %
referred t,o N203; 28 % referred to aniline) were obtained.
GC-analysis:
0.04 ~ of 4-aminobiphenyl, 98.83 % of 1,3-diphenyl triazene, 0.7a ~ of 4-aminoazobenzerJe, 0.33 % of 3 unknown components.
! 171850 - 13 - HOE 81/~ 191 E x a m p l e 9 Substituted 1,3-diaryl triazenes were prepared in the manner described in Example 6 (cf. Table). To this end there was prepared in each case a solution of the aniline derivative in methanol as concentrated as possible, which contained ~.1 % of the corresponding hydrochloride. The semi-molar portion of methyl nitrite (referred to the aniline component) was injected to the resultant solution and stirred overnight~the solid product,s were precipitated with water, suction-filtered and dried.
! l 718~0 Aniline 'rriazene derivatives Yield,¦ Mp derivatives referred to aro-matic amine ~ _ ___ _.
Cl ~ -NH2 Cl-. ~ -N=-NH- ~ -Cl 94 % 132C
~10 ~ 2 ~ Cl Cl ~ B7 ~ ~ 66C
F- ~ -NH2 F- ~ -N=N-NI1- ~ -F 67 '~ 116C
2 ~ -N-N-NH ~ 60 '~ 166C
. . (deconlp.) CII - ~ -N~T CiI3- ~ -N=~-N11- ~ -c~l3 67 g 119C
C~ 2 Cl ~r~ -N--N~ Cl 65 % 1;~C
~ -I~H ~ ~ -N=1~-NH ~ 54 % 1~0C
! 171850 .- 15 - HOE 81/.F 191 Comparative Example Analogously to Example 1 methyl nitrite (from 2.7 l/h of NO and 3.6 l/h of air and methanol) was . introduced into 100 g of aniline and 5 ml of methanol.
The temperature of the reaction mixtue was kept at 22C. 17 g of methyl nitrite were collected in the course of 2 and a half hours in a subsequent trap.
According to gas chromatographic analysis of this reaction mixture upon this period of time, less than 0.2 of 1,3-diphenyl triazene had been formed.
0.32 ~ of aniline, 98.47 % of 1,3-diphenyl triazene, 0.78 ~ of 4-aminoazoben7ene, 0.43 % of 5 unknown components.
E x a m p 1 e 2 The procedure was analogous to that of Example 1, except that 1 % of aniline hydrochloride used as the catalyst gave 34.3 e of 1,3-diphenyl triazene (97.0 ~, referred to N0, 32.4 %, referred to aniline).
GC-analysis:
2.39 % of aniline, 0.16 ~ of 2-aminobiphenyl, 0.30 % of N,N-diphenylamine, 0.19 ~ of 4-amino-biphenyl, 2.70 % of 4-aminoazobenzene, 1.34 % of 8 unknown components.
E x a m p 1 e 3 Proceeding in the manner described in Example 1, a methyl nitrite current was introduced into a mixture of 80 g of aniline, 4 g of aniline hydrochloride (5 %
referred to aniline) and 20 ml of methanol. 33.8 g of product (95.5 %, referred to N0; 31.8 % referred to aniline), were obtained.
GC-analy~is:
0.18 % of 2-amino-biphenyl, 0.44 % of N,N-diphenylamine, 0.22 % of 4-amir.o-biphenyl, 79.62 % of 1,3-diphenyl triazene, 16.97 % of 4-aminoazobenzene, 2.57 ~ of 10 unknown components.
E x a m p 1 e 4 __ When proceeding analogously to Example 1, using, however, in.stead of methanol, ethano', an ethyl nitrite discharge was not observed and 42.0 g of 1,3-diphenyl tria~ene were obtained (97 %s referred to N0; 39.5 %
referred to aniline).
- - - . ,.. ~ .... .. .... ..... . .. . . .
, .
~ 1 71~0 ~ HOE 81/F 191 E x a m p l e 5 The procedure was analogou~ to that of Example 1, using, however, instead of methanol, isopropanol and heating the first reactor at 55C to separate the nitrous acid ester by distillation. There were obtained 41.2 g of 1,3--diphenyl triazene (94.5 % referred to NO;
38.7 ~ referred to aniline~.
~C-analysis:
0.1 % of aniline, 98.0 % of 1,3-diphenyl triazene, 0.2 % of 4-aminoazobenzene, 1.7 % of 13 unknown components.
E x a m p l e 6 Methyl nitrite (from 8.1 l/h of NO; 10.8 l/h of air and methanol) wa~ introduced into a mixture of 1,000 g of aniline, 1 g of aniline hydroehloride (= 0.1 %
referred to aniline) and 50 ml of methanol placed in a circulation reactor of 2 liters content, in the manner descri.bed in Rxample 1, thus heating the reactor contents to a temperature of 33-35C. Solid triazene precipitated after 3 hours. Half of the reaction mixture was passed to a corresponding reactor of the same s.ize and the contents of both reactors were diluted each with liter of methanol so as to form an ea~ily stirrable mixture. Methyl nitrite (from 8.1 l/h of NO; 10.8 l/h of air and methanol) was introduced into each of both reactors for a further 3.5 hours. The resultant yellow ~uspension was 3tirred for 2 hours and withdrawn in vacuo from the apparatus. Triazene was precipitated in a receptable with water. There were obtained 710 g (99.5 %
referred to NO; 67.2 % referred to aniline) Or slightly yellow 1.4 diphenyl triazene.
GC-analy~is:
0.11 % of aniline, 0.04 % of 4 aminobiphenyl, ~ ~7~8~0 - 12 - HOE 81_E` 191 99.54 ~ of 1,4-diphenyl triazene, 0.02 % of 4-aminoazobenzene, 0.25 ~ of 1 unknown component.
E x a m p l e 7 In a manner analogous to Example 6, mQthyl nitrite (from 8.1 l/h of NO; 10.8 l/h of air and methanol) was introduced into a mixture of 800 g of aniline, 1 g of aniline nydrocbloride and 50 ml of methanol. After halving and diluting the contents, methyl nitrite was injected into both reactors for 4 hours each and the batches were allowed to stand overnight to complete their reaction. There were obtained 820 g (100 % referred to NO; 96.6 p referred to aniline) of yellow triazene.
GC-analy~is.
0.71 % of aniline, o.38 ~ of N,N-diphenyl amine, 0.09 % of 4-aminobiphenyl, 93.56 % of 1,3-diphenyl triazene, 4.27 % of 4-aminoazobenzene, 0.98 % of 6 unknown components.
E x a rn p l e 8 In a manner analogous to Example 6, methyl nitrite waA introduced into a mixture Or 500 g of aniline, 0.5 g of aniline hydrochloride and 20 rnl of rnethanol. Methyl nitrite had been produced by passing a technical nitrose mixture (11 % of nitrose, degree of oxidation 33 ~, 38 l/h) through methanol. The gas current wa~ switched off after 6 hours, the mixture was stirred for one hour, triazene was preciitated with water, suction-filtered and dried. 148 g of slightly yellow crystals (99 %
referred t,o N203; 28 % referred to aniline) were obtained.
GC-analysis:
0.04 ~ of 4-aminobiphenyl, 98.83 % of 1,3-diphenyl triazene, 0.7a ~ of 4-aminoazobenzerJe, 0.33 % of 3 unknown components.
! 171850 - 13 - HOE 81/~ 191 E x a m p l e 9 Substituted 1,3-diaryl triazenes were prepared in the manner described in Example 6 (cf. Table). To this end there was prepared in each case a solution of the aniline derivative in methanol as concentrated as possible, which contained ~.1 % of the corresponding hydrochloride. The semi-molar portion of methyl nitrite (referred to the aniline component) was injected to the resultant solution and stirred overnight~the solid product,s were precipitated with water, suction-filtered and dried.
! l 718~0 Aniline 'rriazene derivatives Yield,¦ Mp derivatives referred to aro-matic amine ~ _ ___ _.
Cl ~ -NH2 Cl-. ~ -N=-NH- ~ -Cl 94 % 132C
~10 ~ 2 ~ Cl Cl ~ B7 ~ ~ 66C
F- ~ -NH2 F- ~ -N=N-NI1- ~ -F 67 '~ 116C
2 ~ -N-N-NH ~ 60 '~ 166C
. . (deconlp.) CII - ~ -N~T CiI3- ~ -N=~-N11- ~ -c~l3 67 g 119C
C~ 2 Cl ~r~ -N--N~ Cl 65 % 1;~C
~ -I~H ~ ~ -N=1~-NH ~ 54 % 1~0C
! 171850 .- 15 - HOE 81/.F 191 Comparative Example Analogously to Example 1 methyl nitrite (from 2.7 l/h of NO and 3.6 l/h of air and methanol) was . introduced into 100 g of aniline and 5 ml of methanol.
The temperature of the reaction mixtue was kept at 22C. 17 g of methyl nitrite were collected in the course of 2 and a half hours in a subsequent trap.
According to gas chromatographic analysis of this reaction mixture upon this period of time, less than 0.2 of 1,3-diphenyl triazene had been formed.
Claims (10)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the preparation of a 1,3-diaryl triazene in which an alkyl nitrite is reacted at a temperature between room temerature and temperatures slightly above room temperature with a primary aromatic monoamine and in which the alkyl nitrite which is gaseous at the temperature applied is introduced into the primary aromatic monoamine which is liquid at the temperature applied or dissolved in a polar protic solvent, in the presence of a small quantity of acid.
2. A process as claimed in claim 1 in which the alkyl nitrite is methyl nitrite, ethyl nitrite or a mixture thereof.
3. A process as claimed in claim 1 in which the primary aromatic monoamine is a compound of the formula wherein R1, R2 and R3, independent of each other, are H, halogen, alkyl and NO2.
4. A process as claimed in claim 1, claim 2 or claim 3 in which the reaction is carried out at a temperature of from about 10 to 50°C.
5. A process as claimed in claim 1, claim 2 or claim 3 in which the reaction is carried out at a temperature of from about 20 to 35°C.
6. A process as claimed in claim 1, claim 2 or claim 3 in which the polar protic solvent is a C1-C4 alcohol.
7. A process as claimed in claim 1, claim 2 or claim 3 in which the polar protic solvent is a C1-C4 alcohol and is the alcohol on which the alkyl nitrite is based.
8. A process as claimed in claim 1, claim 2 or claim 3 in which the acid is a mineral acid.
9. A process as claimed in claim 1, claim 2 or claim 3 in which the quantity of acid is in the range of from about 0.01 to 5 equivalent % per mol of primary aromatic monoamine.
10. A process as claimed in claim 1, claim 2 or claim 3 in which the quantity of acid is in the range of from about 0.05 to 1 equivalent % per mol of primary aromatic monoamine.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3131115.6 | 1981-08-06 | ||
| DE19813131115 DE3131115A1 (en) | 1981-08-06 | 1981-08-06 | METHOD FOR PRODUCING 1.3-DIARYLTRIAZENES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1171850A true CA1171850A (en) | 1984-07-31 |
Family
ID=6138705
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000408799A Expired CA1171850A (en) | 1981-08-06 | 1982-08-05 | Process for the manufacture of 1,3-diaryl triazenes |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0071901A1 (en) |
| JP (1) | JPS5835159A (en) |
| CA (1) | CA1171850A (en) |
| DE (1) | DE3131115A1 (en) |
| ZA (1) | ZA825656B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5346486B2 (en) | 2007-04-26 | 2013-11-20 | 花王株式会社 | Hair dye composition |
| JP7109943B2 (en) * | 2017-03-27 | 2022-08-01 | キヤノン株式会社 | PIGMENT DISPERSION, TONER MANUFACTURING METHOD, WATER-BASED INK AND TRIAZO COMPOUND |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2521095A (en) * | 1950-09-05 | Process of preparing triazenes | ||
| DE2453216C3 (en) * | 1974-11-09 | 1978-05-03 | Hoechst Ag, 6000 Frankfurt | Process for the preparation of diazoaminobenzene |
| US4279815A (en) * | 1979-01-09 | 1981-07-21 | Herkes Frank E | Production of high-quality aromatic amino azo compounds by the rearrangement of 1,3-diaryl triazenes |
-
1981
- 1981-08-06 DE DE19813131115 patent/DE3131115A1/en not_active Withdrawn
-
1982
- 1982-07-30 EP EP82106881A patent/EP0071901A1/en not_active Withdrawn
- 1982-08-05 CA CA000408799A patent/CA1171850A/en not_active Expired
- 1982-08-05 ZA ZA825656A patent/ZA825656B/en unknown
- 1982-08-05 JP JP57135794A patent/JPS5835159A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| DE3131115A1 (en) | 1983-02-24 |
| JPS5835159A (en) | 1983-03-01 |
| EP0071901A1 (en) | 1983-02-16 |
| ZA825656B (en) | 1983-06-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Polyakov et al. | Imine exchange in O‐aryl and O‐alkyl oximes as a base reaction for aqueous ‘dynamic’combinatorial libraries. A kinetic and thermodynamic study | |
| CN111848526B (en) | Polysubstituted 1, 4-dihydropyridazine and pyridazine derivatives and synthetic method thereof | |
| US5831093A (en) | Preparation of n-aryl- and n-hetarylhydroxylamines | |
| CA1171850A (en) | Process for the manufacture of 1,3-diaryl triazenes | |
| Bakke et al. | Selective vicarious nucleophilic amination of 3-nitropyridines | |
| JPS61500614A (en) | Decomposition of DNPI in total nitric acid nitration process | |
| Mizutani et al. | Hydrogen‐bonding‐based thermochromic phenol–amine complexes | |
| GB2289675A (en) | Process for the preparation of imidazopyridines and imidazolutidine | |
| EP0296221B1 (en) | Process for preparing 4,6-dinitroresorcinol | |
| TW321637B (en) | ||
| KR100303593B1 (en) | Process for the preparation of pyridyl methyl aminotriazinone | |
| CN111978201B (en) | Synthesis method of N, N' -diaryl benzoyl hydrazine compound | |
| US6198001B1 (en) | Manufacturing method for 4-nitrosoaniline from urea and nitrobenzene | |
| EP0617004A1 (en) | Preparation of N-substituted-N'-phenyl-P-phenylenediamines | |
| US5026864A (en) | Preparation of 2-chloro-5-aminomethyl-pyridine | |
| US3978049A (en) | Process for the preparation of hydrazine compounds | |
| EP1233941B1 (en) | The preparation of 4,4'-dinitrodiphenylamine from urea and nitrobenzene | |
| Boyd et al. | The action of amines on 1, 3, 4-oxadiazolium salts | |
| Hudson et al. | The electrochemical oxidation of polyfluoroaromatic amines—I: The synthesis of fluorophenazines | |
| US4028344A (en) | α-ISOCYANATO AND α-ISOTHIOCYANATO AZOS AND THEIR DERIVATIVES | |
| JPH082848B2 (en) | Process for producing 4-nitrosodiphenylamines | |
| US3910949A (en) | Manufacture of 1,2-dimethyl-3,5-diphenylpyrazolium methylsulfate in a single reaction zone | |
| CN113149858B (en) | Synthesis method of intermolecular N-N bonding and compound correspondingly synthesized | |
| Ozeryanskii et al. | peri-Naphthylenediamines: 22. Synthesis of 1, 4, 5-tris (dimethylamino) naphthalene and other “proton sponge” 4-amino derivatives | |
| CN117658866A (en) | Synthesis method of azido amino acid derivative |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEC | Expiry (correction) | ||
| MKEX | Expiry |