DE2121671A1 - Process for the production of azo dyes - Google Patents

Description

My / Mx

Process for the production of azo dyes

(Addition to patent (application P 20 63 717.6).

The subject of the patent (application P 20 63 717.6) is

a process for the preparation of azo dyes by acidic coupling of diazotized amines with coupling components, which thereby is characterized in that the coupling takes place in the presence of amides of lower aliphatic carboxylic acids.

In further processing of the subject matter of the invention of this application it has now been found that the process is particularly useful for the preparation of dyes of the formula

NH ₂ OH DN = N

(D

HO ₃ S SO ₃ H

where D is a phenyl nucleus which is optionally substituted by electron donating radicals,

suitable. These dyes are obtained by acidic coupling of 1-amino-8-hydroxynaphthalene-3,6-diaulfonic acid (Η-acid) with

2098 ^ / 1155

diazotized amines of the formula

D - NH ₂ (II)

where D has the above meaning,

in the presence of amides of lower aliphatic carboxylic acids, preferably dimethylformamide.

The following substituents may be mentioned as electron-donating radicals, for example: C * -C ^ -alkyl such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert. Butyl, hexyl, cyclohexyl, methylcyclohexyl; Hydroxy, C ₁ -C ^ -alkoxy, especially methoxy and ethoxy, aryloxy, especially phenoxy and _{phenoxy substituted by C 1} "-C ^ - alkyl or chlorine, C ^ -C ^ -alkyl and arylsulfonyloxy, especially methyl- or ethylsulfonyloxy and optionally phenylsulfonyloxy substituted, for example, by Cj-C ^ -alkyl or halogen, such as phenyl-, toluyl- and chlorophenylsulphonyloxy; acylamino, in particular formyl-, C ^ r-Cg-alkylcarbonyl- and arylcarbonyl-, in particular optionally by nitro, halogen, in particular chlorine and C ₁ -C ^ - alkyl substituted phenylcarbonylamino and N-alkylacylamino, in particular NC ₁ -C ^ -alkyl-acylamino, where acylamino has the abovementioned meaning, furthermore halogen such as Cl and Br.

The process is, as described in German patent application P 20 63 717.6, carried out in such a way that the Η-acid (as coupling component) is dissolved or suspended in the acid amide, optionally in the presence of solubilizers such as urea and generally the adding aqueous solution or suspension of the diazonium salt. The coupling takes place at the specified temperatures, preferably at 0-10 ^° C.

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_{Diazo components ISJH 2 which} can be used for the acidic coupling with the Η-acid are, for example: aniline, 2-, 3- or 4-methylaniline, 2-, 3-. or 4-methoxy- (or ethoxy) -aniline, 2-methyl-4- or 5-chloro-aniline, 3- or 4-chloro-aniline, 3- or 4-acetylamino-aniline, 4-acetyl-methyl-amino-aniline , 4-Benzoyl- (or chlorobenzoyl) -amino ~ aniline, 4- (4 ^! -Nitrobenzoyl) amino-aniline, 4-benzoyl-ethyl-amino-aniline, 4-hydroxy-3-carboxy-aniline, 2-, 3- or 4-aminodiphenyl ether, 4-amino-2-chloro-diphenyl ether, 4-amino-4'-chloro-diphenyl ether, 4-amino-2,2 * -dichlorodiphenyl ether, 2-amino-2 * -methyl- diphenyl ether, 4- (benzenesulfonyl-oxy) -aniline.

The monoazo dyes of the formula (I) obtained by the claimed process are valuable intermediate dyes, which are suitable for the construction of new polyazo dyes. They are used as coupling components.

Le A 13 723 -3-

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example 1

In a well-stirred suspension of 34.1 parts (= 0.1 mol) Η-acid (mono-sodium salt) and 550 parts by volume of dimethylformamide are added dropwise at 0-5 ° C within one hour aqueous solution (200 parts by volume) of 0.1 mol of phenyldiazonium chloride (prepared from 9.3 parts, 0.1 mol, aniline).

After stirring at room temperature for 24 hours, the mixture is added with 700 parts by volume of saturated sodium chloride solution and sucks the precipitated pure dye £ ib.

The yield is over 80 %,

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Example 2

9.3 parts (0.1 mol) of aniline are diazotized as usual. The diazonium salt solution (300 parts by volume) is within one hour at 5 - 10 ⁰ C in a solution of 34.1 parts (0.1 mol) of 1-amino-8-hydroxy-naphthalene-3,6-disulfonic acid ( H-acid) in 400 parts by volume of dimethylformamide and 50 parts of urea · dropwise and as long stirred at 10 to 20 ⁰ C, until the clutch stops. 400 parts by volume of saturated sodium chloride solution are then added and, after stirring for one hour, the dyestuff which has precipitated is filtered off with suction and pressed sharply.

The sodium salt of the monoazo dye obtained dissolves in water with a red color. When smearing the dye solution with diluted hydrochloric acid, the tone changes to purple.

About 190 g of dye paste are obtained, which are optionally redissolved under alkaline conditions. The yield is over 90% of the _t za by coupling the monoazo dye obtained with diazotized aniline solution is determined.

Using the aromatic amines listed below, monoazo dyes become acidic in an analogous manner coupled Η-acid, the solution color of which is given in water (sodium salt):

4-methyl aniline Red 3-methyl ~ aniline Red 4- (acetylamino) aniline Red 4-methoxy-aniline Red 4-ethoxy-aniline Red 2-methyl-aniline Red 4- (acetyl-methylamino) aniline Red 4- (benzoylethylamino) aniline Red 4- (4 ^! -Nitrobenzoylamino) aniline red-violet 4-chloro-aniline Red 4-chloro-2-methylaniline Red Le A 13 723 -5- 209847/1155

5-chloro-2-methylaniline red

4-Hydroxy-3-carboxy-aniline red

4-ethoxy-3-sulfo-aniline red

2-amino-diphenyl ether red

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Claims (1)

Claim * Process for the preparation of azo dyes by acidic coupling of diazotized amines with coupling components in the presence of amides of lower aliphatic carboxylic acids according to patent (application P 20 63 717.6), characterized in that that one amines of the formula D-NH ₂ where D is a phenyl nucleus which is optionally substituted by electron donating radicals, couples with i-amino-8-hydroxynaphthalene-5,6-disulfonic acid. - - Le A 13 723 -7- 209847/1155