DE19721619A1 - Diazotisation of solid aromatic amine and nitrogen di:oxide, with high productivity - Google Patents

Abstract

Diazotisation of aromatic amines (I) in the solid state with nitrogen dioxide (NO2) comprises reacting (I) with NO2, in a gaseous or liquid state, in the presence of an inert diluent. Also claimed are methods of producing azo dyes by: (i) treating (I) with gaseous or liquid NO2 in the presence of a solid coupling component and an inert diluent; or (ii) reacting (I) with gaseous or liquid NO2 in the presence of an inert diluent and then reacting with a coupling component in a solid or liquid state, or in solution.

Description

The present invention relates to a new method for diazo tion of aromatic amines by reacting these amines with Nitrogen dioxide and process for the production of azo dye fen.

In Mol. Cryst. Liq. Cryst, vol. 276, pages 315 to 337, 1996, and J. Prakt. Chem, vol. 339, pages 256 to 260, 1997, is the diazo Different solid aniline derivatives with gaseous substances Described nitrogen dioxide.

The object of the present invention was to develop a new method for the diazotization of aromatic amines using nitrogen dioxide to sit down. The new process should also be used on a larger scale scale and the diazo Provide nium salts in high space-time yield.

It has now been found that the diazotization of solid aggre present aromatic amines using nitrogen Dioxide succeeds advantageously if you add the aromatic amine Nitrogen dioxide, which is in gaseous or liquid aggregates was available in the presence of an inert diluent Brings reaction.

Suitable aromatic amines that exist in solid state lie and the diazo by means of the inventive method can be z. B. those that differ from aniline, Anthraquinone or from a five-membered aronatic hetero derive cyclic amine, the one to three heteroatoms, out chooses from the group consisting of nitrogen, oxygen and Sulfur, in the heterocyclic ring and by one Benzene, thiophene, pyridine or pyrimidine ring must be fused can.

Heterocyclic amines are e.g. B. those from the pyrrole, furan, Thiophene, pyrazole, imidazole, oxazole, isoxazole, thiazole, Isothiazole, triazole, oxadiazole, thiadiazole, benzofuran, Benzthiophene, benzimidazole, benzoxazole, benzthiazole, benziso thiazole, pyridothiophene, pyrimidothiophene, thienothio phen or thienothiazole series.  

Aromatic amines derived from one Aniline, anthraquinone or from a heterocyclic amine from the Pyrrole, thiophene, pyrazole, thiazole, isothiazole, triazole, Thiadiazole, benzthiophene, benzthiazole, benzisothiazole, Pyridothiophene, pyrimidothiophene, thienothiophene or thieno thiazole series.

Aromatic amines of the formula I are of particular importance

D-NH ₂ (I),

in the
D ¹ for a radical of the formula

or

stand in what
L ¹ nitro, cyano, C ₁ -C ₄ alkoxycarbonyl, C ₁ -C ₆ alkanoyl, benzoyl, C ₁ -C ₆ alkylsulfonyl, optionally substituted phenyl sulfonyl or a radical of the formula -CH = T, in which T is the meaning tion of hydroxyimino, C ₁ -C ₄ alkoxyimino or a residue of a CH-acidic compound H ₂ T,
L ² is hydrogen, C ₁ -C ₆ alkyl, halogen, hydroxy, mercapto, ge be substituted by phenyl or C ₁ -C ₄ -alkoxy-substituted C ₁ -C ₆ alkoxy, optionally substituted phenoxy, ge optionally phenyl-substituted C ₁ -C ₆ alkylthio, optionally substituted phenylthio, C ₁ -C ₆ alkylsulfonyl or optionally substituted phenylsulfonyl,
L ³ cyano, C ₁ -C ₄ alkoxycarbonyl, amino or nitro,
L ^{4 is} hydrogen, C ₁ -C ₆ alkyl or phenyl,
L ⁵ C ₁ -C ₆ alkyl or phenyl,
L ⁶ hydrogen, cyano, C ₁ -C ₄ alkoxycarbonyl, C ₁ -C ₆ alkanoyl, thiocyanato or halogen,
L ⁷ nitro, cyano, C ₁ -C ₆ alkanoyl, benzoyl, C ₁ -C ₄ alkoxycarbonyl, C ₁ -C ₆ alkylsulfonyl, optionally substituted phenyl sulfonyl or a radical of the formula -CH = T, where T is the above has the meaning given,
L ^{8 is} hydrogen, C ₁ -C ₆ alkyl, cyano, halogen, C ₁ -C ₆ alkoxy optionally substituted by phenyl or C ₁ -C ₄ alkoxy, optionally substituted by phenyl C ₁ -C ₆ alkylthio, ge optionally substituted phenylthio, C ₁ -C ₆ alkylsulfonyl, optionally substituted phenylsulfonyl or C ₁ -C ₄ alkoxycarbonyl,
L ⁹ is cyano, optionally substituted phenyl C ₁ -C ₆ alkyl optionally substituted by phenyl C ₁ -C ₆ alkylthio, optionally substituted phenyl, thienyl, thienyl C ₁ -C ₄ -alkyl, pyridyl or C ₁ -C ₄ -Alkylpyridyl,
L ¹⁰ phenyl or pyridyl,
L ¹¹ trifluoromethyl, nitro, C ₁ -C ₆ -alkyl, phenyl, optionally substituted by phenyl-substituted C ₁ -C ₆ -alkylthio or C ₁ -C ₆ -dialkylamino,
L ¹² C ₁ -C ₆ alkyl, phenyl, 2-cyanoethylthio or 2- (C ₁ -C ₄ alkoxy carbonyl) ethylthio,
L ¹³ hydrogen, nitro or halogen,
L ^{14 is} hydrogen, cyano, C ₁ -C ₄ alkoxycarbonyl, nitro or halogen and
L ¹⁵ , L ¹⁶ and L ^{17 are the} same or different and are each independently hydrogen, C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, halogen, nitro, cyano, optionally substituted C ₁ -C ₄ alkoxycarbonyl, C ₁ -C ₆ alkylsulfonyl, optionally substituted phenylsulfonyl or optionally substituted phenylazo.

All alkyl or in the formulas mentioned above Alkenyl groups can be straight-chain or branched.

If substituted alkyl radicals occur in the above formulas, as substituents, unless noted otherwise, for. B. cyclohexyl, phenyl, C ₁ -C ₄ alkylphenyl, C ₁ -C ₄ alkoxy phenyl, halophenyl, C ₁ -C ₈ alkanoyloxy, C ₁ -C ₈ alkylamino carbonyloxy, C ₁ -C ₂₀ alkoxycarbonyl, C ₁ -C ₂₀ alkoxycarbonyloxy, the alkyl chain of the last three radicals optionally being interrupted by 1 to 4 oxygen atoms in ether function and / or substituted by phenyl or phenoxy, cyclohexyloxy, phenoxy, halogen, hydroxy or cyano. The alkyl radicals generally have 1 or 2 substituents.

If alkyl radicals occur in the above formulas, which are caused by Oxygen atoms are interrupted in ether function, so are so unless otherwise noted, preference is given to those alkyl radicals which by 1 to 4 oxygen atoms, in particular 1 to 2 oxygen atoms are interrupted in ether function.  

If substituted phenyl or pyridyl radicals occur in the formulas mentioned above, unless otherwise noted, substituents such as. B. C ₁ -C ₈ alkyl, C ₁ -C ₈ alkoxy, halogen, in particular chlorine or bromine, nitro or carboxyl. The phenyl or pyridyl radicals generally have 1 to 3 substituents.

The following are exemplary lists for the residues mentioned.

Residues L ² , L ⁴ , L ⁵ , L ⁸ , L ⁹ , L ¹¹ , L ¹² , L ¹⁵ , L ¹⁶ and L ¹⁷ are e.g. B. methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl or 2-methyl pentyl.

L ⁹ are still z. B. benzyl or 1- or 2-phenylethyl.

L ² , L ⁸ , L ⁹ and L ¹¹ are still z. B. methylthio, ethyl thio, propylthio, isopropylthio, butylthio, isobutylthio, pentylthio, hexylthio, benzylthio or 1- or 2-phenylethylthio.

L ² and L ⁸ are still z. B. phenylthio, 2-methylphenylthio, 2-methoxyphenylthio or 2-chlorophenylthio.

Residues L ² , L ⁸ , L ¹⁵ , L ¹⁶ and L ¹⁷ are still z. B. methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, pentyloxy, isopentyloxy, neopentyloxy, tert-pentyloxy, hexyloxy or 2-methylpentyloxy.

L ⁶ are, as are also L ² , L ⁸ , L ¹³ , L ¹⁴ , L ¹⁵ , L ¹⁶ and L ¹⁷ , z. B. fluorine, chlorine or bromine.

L ⁷ are, as are also L ¹ , L ² , L ⁸ , L ¹⁵ , L ¹⁶ and L ¹⁷ , z. Methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropyl pylsulfonyl, butylsulfonyl, isobutylsulfonyl sec-butylsulfonyl, pentylsulfonyl, Isopentylsulfonyl, Neopentylsulfonyl, Hexylsulfo nyl, phenylsulfonyl, 2-methylphenylsulfonyl, 2-Methoxyphenylsul fonyl or 2-chlorophenylsulfonyl.

L ³ radicals, as are also L ¹ , L ⁶ , L ⁷ , L ⁸ , L ¹⁴ , L ¹⁵ , L ¹⁶ and L ¹⁷ radicals, e.g. B. methoxycarbonyl, ethoxycarbonyl, propoxy carbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl or sec-butoxycarbonyl.

L ¹⁵ , L ¹⁶ and L ¹⁷ are still z. B. 2-phenoxyethoxycarbonyl, 2- or 3-phenoxypropoxycarbonyl, 2- or 4-phenoxybutoxycar bonyl, phenylazo, 4-nitrophenylazo or 2,4-dinitro-6-bromophenyl azo.

L ² and L ⁸ are still z. B. 2-methoxyethoxy, 2-ethoxy ethoxy, 2- or 3-methoxypropoxy, 2- or 3-ethoxypropoxy, 2- or 4-methoxybutoxy, 2- or 4-ethoxybutoxy, 5-methoxypentyloxy, 5-ethoxypentyloxy, 6- Methoxyhexyloxy, 6-ethoxyhexyloxy, benzyloxy or 1- or 2-phenylethoxy.

L ¹¹ are still z. B. dimethylamino, diethylamino, di propylamino, diisopropylamino, dibutylamino, dipentylamino, dihexylamino or N-methyl-N-ethylamino.

L ¹² are still z. B. 2-methoxycarbonylethylthio or 2-ethoxycarbonylethylthio.

L ⁹ are still z. B. phenyl, 2-, 3- or 4-methylphenyl, 2,4-dimethylphenyl, 2-, 3- or 4-methoxyphenyl, 2-, 3- or 4-chlorophenyl, 2- or 3-methylthienyl or 2-, 3- or 4-methyl pyridyl.

L ¹ , L ⁶ and L ⁷ are still z. B. formyl, acetyl, propionyl, butyryl, pentanoyl or hexanoyl.

If L ¹ or L ^{7 are} the radical -CH = T, in which T is derived from a CH-acidic compound H ₂ T, H ₂ T z. B. Compounds of formula

come into consideration, whereby
Z ¹ cyano, nitro, C ₁ -C ₄ alkanoyl, optionally substituted benzoyl, C ₁ -C ₄ alkylsulfonyl, optionally substituted phenylsulfonyl, C ₁ -C ₄ alkoxycarbonyl, C ₃ -C ₄ alkenyloxy carbonyl, phenoxycarbonyl, carbamoyl , C ₁ -C ₄ mono- or dialkylcarbamoyl, optionally substituted phenyl carbamoyl, optionally substituted phenyl, benzothiazole-2-yl, benzimidazol-2-yl, 5-phenyl-1,3,4-thiadiazol-2-yl or 2-hydroxyquinoxalin-3-yl,
Z ² C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy or C ₃ -C ₄ alkenyloxy,
Z ³ C ₁ -C ₄ alkoxycarbonyl, C ₃ -C ₄ alkenyloxycarbonyl, phenyl carbamoyl or benzimidazol-2-yl,
Z ⁴ cyano, C ₁ -C ₄ alkoxycarbonyl or C ₃ -C ₄ alkenyloxycarbonyl,
Z ^{5 is} hydrogen or C ₁ -C ₆ alkyl,
Z ⁶ cyano, carbamoyl or C ₁ -C ₄ alkanoyl,
Z ^{7 is} hydrogen, C ₁ -C ₄ alkyl or phenyl,
Z ⁸ C ₁ -C ₄ alkyl,
Z ⁹ cyano, carbamoyl or C ₁ -C ₄ alkoxycarbonyl and
X is oxygen, sulfur or imino.

The radical which is derived from compounds of the formula IIIa, IIIb or IIIc in which Z ^{1 is} cyano, C ₁ -C ₄ -alkanoyl, C ₁ -C ₄ -alkoxycarbonyl or C ₃ -C ₄ -alkenyloxycarbonyl, Z ² C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy or C ₃ -C ₄ alkenyloxy, Z ³ C ₁ -C ₄ alkoxycarbonyl or C ₃ -C ₄ alkenyloxycarbonyl and Z ⁴ mean cyano.

Particularly noteworthy is the remainder of those derived from compounds of the formula IIIa, IIIb or IIIc, in which Z ^{1 is} cyano, C ₁ -C ₄ alkoxycarbonyl or C ₃ -C ₄ alkenyloxycarbonyl, Z ² C ₁ -C ₄ alkoxy or C ₂ -C ₄ alkenyloxy, Z ³ C ₁ -C ₄ alkoxycarbonyl or C ₃ -C ₄ alkenyloxycarbonyl and Z ⁴ mean cyano.

Are inert diluents in the sense of the invention those in gaseous or liquid state of matter Understand substances that are unchanged under the reaction conditions remain and which are unable to dissolve the aromatic amines gen. That means in particular that the solubility of the aromati the amines in the inert diluents is <0.1 g / l. A an essential task of the inert diluents is to the Re released in the diazotization of the aromatic amines absorb action heat.

Suitable inert diluents in gaseous aggregate condition exist, z. B. noble gases such as helium, neon or Ar gon, nitrogen, nitrous oxide, air or carbon dioxide where for carbon dioxide in gaseous or liquid state or in a supercritical state.

Suitable inert diluents that are in liquid Aggregatzu are such. B. hydrocarbons, for example C ₅ -C ₈ alkanes, such as pentane, hexane, heptane, octane or isooctane, benzene, toluene, xylene, tetralin, decalin, dimethylnaphthalene, mineral oils, such as gasoline, kerosene or diesel oil, or halocarbons, for example, chlorinated hydrocarbons such as dichloromethane, trichloromethane, tetrachloromethane, dichloroethane, dichloroethylene, chlorobenzene or dichlorobenzene, or chloro (bromo) fluorocarbons such as trichlorofluoromethane, dichlorodifluoromethane, bromochlorodifluoromethane, Dibromdifluorme than, chlorotrifluoromethane, bromotrifluoromethane, Dichlorfluor methane, chlorodifluoromethane, 1,1,2, 2-tetrachlorodifluoroethane, 1,1,2-trichlorotrifluoroethane, 1,2-dichlorotetrafluoroethane, 1,2-di-bromotetrafluoroethane, chloropentafluoroethane, 1,2-dibromo-1,1-difluoroethane, 2-chloro-1,1,1- trifluoroethane, 1-chloro-1,1-difluoroethane, 1,1-dichlorodifluoroethylene, chlorotrifluoroethylene, 1-chloro-2,2-difluoroethylene or 1,1-difluoroethylene.

The use of nitrogen or air as in gaseous form diluent present is preferred, wherein the use of air is particularly noteworthy.

The use of hydrocarbons, in particular C ₅ -C ₈ alkanes, as diluents in the liquid state is preferred.

The diazotization reagent nitrogen dioxide comes either in gas form or liquid state of aggregation for use.

The inventive method is at a temperature of -70 to + 70 ° C, preferably -50 to + 50 ° C and in particular -10 to + 30 ° C.

You usually work at a pressure of 0.1 to 200 bar. For all inert diluents except carbon dioxide is a pressure of 0.1 to 5, especially 0.8 to 2 bar before moves.

The terms gaseous or liquid aggre used here The current status refers to the prevailing reaction conditions, d. H. to the above temperature and pressure areas.

The following working methods are of particular importance.

• A) The aromatic amine is suspended or dispersed in a dilution in the liquid state medium, optionally with the addition of customary dispersants auxiliaries with in gaseous or liquid aggregate the present nitrogen dioxide reacted.
• B) The aromatic amine is e.g. B. in a fluidized bed or as a powder bed in a fixed bed with a mixture of gaseous Physical state of the existing diluent and in gas The present physical state of nitrogen dioxide flows.
• C) The aromatic amine is in a liquid state nitrogen dioxide present in the presence of a gas According to the physical state of the diluent to the reak tion brought.  
• D) The aromatic amine is in a printing apparatus with a Mixture of nitrogen dioxide and carbon dioxide either under half or above the critical point of carbon dioxide acts.

Variants A) and B) deserve special mention.

In variant B) the aromatic amine flows through with the gas mixture at a sufficiently high speed so that the temperature of the gas mixture flowing out of the reactor not more than 20 ° C, preferably not more than 10 ° C and ins special is not more than 5 ° C warmer than that in the vortex layer or gas mixture flowing into the fixed bed. The Volume ratio of diluent: nitrogen dioxide is in usually 1:10 to 1000: 1.

It is advantageous to pass the gas through the aromatic amine mixture and return it several times, if necessary under Dosing of fresh gas mixture or one of its components to pass through the aromatic amine.

It can be particularly advantageous to pass the gas mixture through a heat exchanger located outside the reaction zone conduct so as to dissipate the heat of reaction.

In the process according to the invention, the aromatic amines and Nitrogen dioxide in a molar ratio of 1: 1 to 1:10, preferably 1: 1 to 1: 4 and in particular 1: 1 to 1: 2 for use.

In the diazotization of such aromatic amines, the two have amino groups capable of diazonium grouping (tetra zocomponents) the share of doubles, of course Nitrogen dioxide.

In the process according to the invention, they fall from the aromatic Amines resulting diazonium salts usually in the form of their Nitrates. When using such aromatic amines, which have acidic groups, they can also be obtained as betaines len.

Depending on the physical state of the inert diluent, whom this is usually applied in the following amounts.  

In the case of the inert in the gaseous state Diluent is the volume ratio of diluent with tel: nitrogen dioxide generally 1:10 to 1000: 1, preferably 1:10 to 200: 1 and especially 1: 2 to 50: 1.

In the case of the inert in the liquid state Diluent is the weight ratio of diluent tel: aromatic amine in general 1:20 to 100: 1, preferred wise 1: 5 to 20: 1.

The method according to the invention is advantageously performed as follows taken.

Option A)

The aromatic amine, which is in its solid state, becomes in a suitable reaction apparatus, e.g. B. in a stir container, in the Ver in liquid state fertilizers, if necessary with the addition of conventional ones Dispersing aids, suspended or dispersed. With scramble Ren is then in the gaseous or liquid state of matter present nitrogen dioxide metered into the mixture, for. B. by Introducing gaseous nitrogen dioxide or by dropping of liquefied nitrogen dioxide.

After a period of 0.5 to 6 hours, the implementation in the generally ended and the diazonium salt of the aromatic amine is in the form of nitrate or in betaine form as a solid or as a liquid and can be separated from the diluent and processed directly.

Variant B)

The aromatic amine, which is in its solid state, becomes in a suitable reaction apparatus, e.g. B. in a vortex bed reactor or in a fixed bed reactor, with a mixture from each stick in gaseous state substance dioxide and diluent reacted. After a time period customary for this reaction procedure in Re The reaction is generally 15 minutes to 10 hours completed. The aromatic amine diazonium salt is in shape of nitrate or in betaine form as a solid or as a liquid before and can be processed directly.  

Variant C

The aromatic amine, which is in its solid state, becomes in a suitable reaction apparatus, e.g. B. in a stir container with the liquid state Nitrogen dioxide and in the gaseous state mixed diluent and stirring with reaction brought. After a period of 15 minutes to 10 hours the implementation generally ended. The diazonium salt of the aro Matic amine is in the form of the nitrate as a solid or Liquid before and can stick after removing the remaining stick can be processed directly.

By means of the method according to the invention, both in continuous animal as well as discontinuous work arona can be present in a solid state table amines in a simple manner and with a high space-time yield converted into the corresponding diazonium nitrates or betaines will. The implementation is usually quantitative and the diazo nium salts are obtained in high purity.

The diazonium nitrates or betaines thus obtained can by Coupling with suitable and usual coupling components, e.g. B. those from the aniline, aminonaphthalene, naphthol, aminopyra zole, pyrazolone, aminothiazole, diaminopyridine, hydroxypyri don, aminoquindin or pyrazoloquinazolone series, on itself known way to be converted into azo dyes.

This can e.g. B. done by that the diazonium salt on known manner in an aqueous medium or in the presence of a common organic solvent with the coupling component.

Another object of the present invention is a ver drive to the production of azo dyes. It was namely found that the production of azo dyes by diazotization an aromatic amine and coupling the resulting Diazonium salt with a coupling component advantageous ge succeeds when you see the aroma in a solid state tables amine in the presence of a solid state Coupling component with nitrogen dioxide, which in gaseous is in a liquid or liquid state, in the presence of a treated inert diluent. It goes without saying that here with preferably only such coupling components for use get under the given reaction conditions no Re take action with nitrogen dioxide.  

Aromatic amine and coupling component come in the Re gel in a molar ratio of 0.5 to 2.0, preferably 0.8 to 1.2 and in particular 0.9 to 1.1 for use. When implementing such aromatic amines, the two for diazonium grouping have capable amino groups (tetrazo components), doubled the proportion of the coupling component.

Otherwise apply to the manufacturing process according to the invention azo dyes the above statements. You go expediently so that instead of the aromatic amine each a mixture of aromatic amine and the coupling com component applies.

Another object of the present application is a Ver drive to the production of azo dyes by diazotization an aromatic amine and coupling the resulting Diazoniumsalzes with a coupling component, wherein the aro Matic amine with nitrogen dioxide, which is in gaseous or liquid form physical state, in the presence of an inert ver brings the fertilizer to reaction and then with a Coupling component that is in solid or liquid state or is in solution.

Suitable solvents for the coupling component are e.g. B. What water, acids, such as acetic acid, hydrochloric acid or sulfuric acid, ver thin alkalis, such as dilute sodium hydroxide solution, or those per se common organic solvents.

Otherwise, the above statements apply here Azo clutch.

By means of the new process for dye production, which both in continuous as well as discontinuous mode of operation can be made, it succeeds in the azo dyes easy to produce in a high space-time yield. The Azo dyes are obtained in high yield and purity.

The following examples are intended to explain the invention in more detail.

example 1

• a) 5 g (0.03 mol) of 4-nitroaniline in 20 ml of pentane sets. At 0 ° C 4 ml (0.12 mol) of liquid nitrogen dioxide (liquefied at -8 ° C) in two portions each in added dropwise within 30 min. Then they stirred 0 ° C after 30 min. The resulting 4-nitrophenyldiazonium nitrate separated out as an oily phase and became from the pentane  severed. The 4-nitrophenyldiazonium nitrate thus obtained, was directly implemented further.
• b) A mixture of 45 ml of water and 7.2 g (0.03 mol) of 68% 1,4-Dinethyl-3-cyano-6-hydroxypyrid-2-one was at 50 ° C warms and with 20 ml of 10 wt .-% sodium hydroxide solution on one pH of 8 set. The resulting solution was made up to a Cooled temperature below 5 ° C. About this solution became a solution of the diazonium salt prepared under a) dropped in 50 ml of water within 30 min at 0 to 5 ° C. At the same time, the pH was adjusted using 10% by weight sodium bicarbonate alkali kept at 8. The mixture was stirred at 0 to 5 ° C for 30 min and then presented with conc. Hydrochloric acid pH 5.5 a. The mixture was then stirred at 20 ° C. for 30 minutes, heated to 60 ° C., sucked off the azo dye formed, washed it with water and dried it at 60 ° C under reduced pressure.

7.7 g (yield: 82%) of the dye of the formula were obtained

(Purity: 97.3%).

Example 2

• a) Example 1a) was repeated, but under the following conditions.
  20 g (0.12 mol) 4-nitroaniline
  30 ml of pentane
  12 ml (0.36 mol) of liquid nitrogen dioxide
  Dropping time: 3.5 h (continuous)
  Stirring time: 3 h at room temperature. b) Example 1b) was repeated with the diazonium salt obtained from Example 2a).
  29 g (0.12 mol) of 68% 1,4-dimethyl-3-cy ano-6-hydroxypyrid-2-one were used.
  37.5 g (yield: 100%) of the dye described in Example 1b) (purity 93%) were obtained.

Example 3

• a) 5 g (0.022 mol) of 1-aminoanthraquinone were placed in 20 ml of pentane. At 0 ° C, 2.02 g (0.044 mol) of liquid nitrogen dioxide (liquefied at -8 ° C) were added dropwise over the course of 30 minutes.
  The mixture was then stirred at 0 ° C for 1 h. The resulting anthraquinonediazonium nitrate hydrate separated out as an ocher-colored solid. It had the following IR bands (NaCl pressing): 2290, 1681, 1585, 1329 and 1295 cm ^-1 .
• b) 315 mg (1 mmol) of the diazonium salt obtained in Example 3a) were dissolved in 25 ml of ethanol.
  273 mg (1 mmol) coupling component of the formula
  were placed in 50 ml of ethanol with the addition of 2 mmol of sodium acetate with stirring at room temperature and the above solution was added. A red body of color fell out. After stirring for 30 minutes, the solvent was removed on a rotary evaporator and the crude product was washed three times with water and dried to remove salts and dried. 500 mg (99% yield) of pigment of the formula were obtained
  

Example 4

• a) The following fixed bed reactor was used:
  A vertical glass tube (inner diameter: 12 mm) with a ceramic frit was used as the reaction tube. The reaction tube was integrated on both sides in a closed gas circuit (with gas reservoir, bypass for nitrogen dioxide dosing and gas compressor pump for circulation) with a total volume of 50 l.
  10 g (0.044 mol) of 1-aminoanthraquinone were added to the tube as a powder bed and the bed was compacted by shaking. Then the entire volume of the gas circuit was evacuated, then filled with nitrogen and the apparatus closed. 6.07 g (0.132 mol) of nitrogen dioxide were placed in a bypass, which was connected to the gas circuit via taps. The gas reservoir was cooled via cooling hoses through which cooling water flowed so that the gas temperature in the gas reservoir did not rise above 25 ° C. Using the gas compressor pump, the gas was then passed from above through the fixed bed of 1-aminoanthraquinone at a high flow rate (not measured) and circulated, the nitrogen dioxide being metered into the gas circuit over a period of 2 hours. The gas cycle was carried out for a further 2 h. Excess nitrogen dioxide was then removed using a vacuum pump. 13.5 g (97% yield) of the ocher-colored diazonium nitrate hydrate were kept. It had the same IR bands as the product made in Example 3a.
• b) The diazonium salt prepared in Example 4a) was, as in Example 3b) described by coupling with what is called there ten dichloroquinazolopyrazole in the pigment mentioned there transferred. The results were identical.

Claims (10)

1. A process for the diazotization of aronatic amines lying in solid state using nitrogen dioxide, characterized in that the aromatic amine with nitrogen dioxide, which was in gaseous or liquid state, is reacted in the presence of an inert diluent. 2. The method according to claim 1, characterized in that one used as aromatic amines are those amines which differ from an aniline, anthraquinone or a five-membered aro derive matic heterocyclic amine that one to three Heteroatoms selected from the group consisting of stick substance, oxygen and sulfur, in the heterocyclic ring points and by a benzene, thiophene, pyridine or pyri midring can be fused. 3. The method according to claim 1, characterized in that one as inert diluents, which in gaseous aggregate available, noble gases, nitrogen, air or carbon dioxide used. 4. The method according to claim 1, characterized in that as an inert diluent used in liquid aggregates stand, hydrocarbons or halogenated hydrocarbons fabrics used. 5. The method according to claim 1, characterized in that before diazotization at a temperature of -70 to + 70 ° C. takes. 6. The method according to claim 1, characterized in that the diazotization at a pressure of 0.1 to 200 bar takes. 7. The method according to claim 1, characterized in that one the aronatic amine, suspended or dispersed in one diluent in liquid form, with are in gaseous or liquid state the nitrogen dioxide to react.   8. The method according to claim 1, characterized in that the aromatic amine in a fluidized bed or as a powder bed in a fixed bed with a mixture of gaseous aggregates was present diluent and in gaseous Ag Flows through the existing nitrogen dioxide. 9. Process for the production of azo dyes by diazo formation of an aromatic amine and coupling of the resulting end diazonium salt with a coupling component, thereby characterized in that it was in a solid state aromatic anin in the presence of a solid aggregate present coupling component with nitrogen dioxide, which is in gaseous or liquid state is present in the presence of an inert diluent acts. 10. Process for the production of azo dyes by diazo formation of an aromatic amine and coupling of the resulting end diazonium salt with a coupling component, thereby characterized in that the aromatic amine with nitrogen dioxide, which is in gaseous or liquid state is present in the presence of an inert diluent Brings reaction and then with a clutch compo nente, in solid or liquid state or in Solution is available, implemented.