CH631198A5 - Water-soluble monoazo dyes - Google Patents

Description

The present invention relates to water-soluble monoazo dyes in the form of the free acids of the formula:

HO ^ S.

N.

correspond, in which E means the rest of a coupling component which is free of sulfo groups, and on the application of these dyes to textiles.

The remainder of the coupling component represented by E may be the remainder of any of the known series of coupling components (i.e. compounds that react with a diazonium compound to form an azo dye) provided the coupling component does not contain sulfo groups. E is preferably the residue of a coupling component of the pyrazolone, aminopyrazole, 2,6-dihydroxypyridine, 2,6-diaminopyridine, indole or arylamine series and can contain any of the substituents other than sulfo groups which are present in such residues occurrence.

A preferred class of the dyes according to the invention comprises dyes of the formula:

wherein R1 is hydrogen or optionally substituted alkyl, R2 is hydrogen, optionally substituted alkyl, optionally substituted aryl or cycloalkyl, R3 is hydrogen, halogen, lower alkyl or lower alkoxy 5 and R4 is hydrogen, halogen, lower alkyl, lower alkoxy or acylamino.

In this description, the terms “lower alkyl” or “lower alkoxy” mean alkyl or alkoxy groups which contain 1 to 4 carbon atoms.

io The same or different, optionally substituted alkyl radicals, which can be represented by R1 and R2, are preferably optionally substituted lower alkyl radicals; Examples of such residues are hydroxy lower alkyl, e.g. β-hydroxyethyl, β- or γ-hydroxypropyl and ô-Hy-15 droxybutyl, lower alkoxy lower alkyl, e.g. β-methoxyethyl, β-ethoxyethyl and y-methoxypropyl, aryloxy lower alkyl, e.g. β-phenoxyethyl, cyano-lower alkyl, e.g. Cyanoethyl, aryl-lower alkyl, e.g. Benzyl, chlorobenzyl and β-phenylethyl, acyloxy lower alkyl, e.g. β-acetoxyethyl and β-benzoyloxy-20ethyl, alkoxycarbonyl-lower alkyl, e.g. β-methoxycarbonyl-ethyl, lower alkoxy-lower alkoxycarbonyl-lower alkyl, e.g. ß- (ß-methoxyethoxycarbonyl) ethyl, and chloro-lower alkyl, e.g. y-chloropropyl.

The acylamino groups which can be represented by R4 include, in particular, groups of the formula -NHCOR5 and -NHS02R6, in which R5 denotes hydrogen, alkyl, in particular lower alkyl, aryl or aminoalkyl and R6 denotes optionally substituted lower alkyl or aryl.

The dyes according to the invention can be prepared by coupling diazotized 2-amino-1,3-benzothiazole-5-sulfonic acid with a coupling component containing no sulfone groups.

The 2-amino-1,3-benzothiazole-5-sulfonic acid can be prepared by reducing 3-nitro-4-thiocyanobenzenesulfonic acid, which in turn is obtained from 4-amino-3-nitrobenzenesulfonic acid using a Sandmeyer reaction.

Suitable coupling components for use in the production of the dyes according to the invention include Py-razolones, especially l-aryl-5-pyrazolones, e.g. l-phenyl-3-40 methyl-5-pyrazolone, l-phenyl-3-carboethoxy-5-pyrazolone and l-phenyl-3- (N-phenylcarbamoyl) -5-pyrazolone, in which the 1-phenyl radicals are optionally further substituted can be, e.g. by methyl, methoxy, ethoxy, chlorine, bromine, nitro, sulfamoyl or acetylamino, further 2,6-dihydroxypyridines (or 45 6-hydroxypyrid-2-ones), e.g. 3-cyano-4-methyl-2,6-dihydroxypyridine, 1-ethyl-, 1-butyl- or 1- (2-ethylhexyl) -3-cy-ano-4-methyl-6-hydroxypyrid-2- on, l-ethyl-3-carbamoyl-4-methyl-6-hydroxypyrid-2-one and l-ethyl-4-methyl-6-hydroxy-pyrid-2-one, aminopyrazoles, e.g. l-phenyl-3-methyl-5-ami-50 nopyrazole, l, 3-dimethyl-5-aminopyrazole and 3-phenyl-5-aminopyrazole, 2,6-diaminopyridines, e.g. 3-cyano-4-methyl-2,6-diaminopyridine, 3-cyano-4-methyl-2,6-dibutyaminopyridine and 2,4,6-triaminopyridine, as well as indoles, e.g. 2-phenylindole, l-ethyl-2-phenylindole and 1,2-dimethylindole.

55

Particularly suitable coupling components are aryl amines, e.g. N, N-diethylaniline, N, N-diethyl-m-toluidine, N-benzylaniline, N- (o-chlorobenzyl) -aniline, N-ethyl-N-benzyl-m-toluidine, N-butyl-N-benzyl- m-toluidine, N-ethyl-N- (o-chloro-60 benzyl) -m-toluidine, N-ethyl-N- (ß-hydroxyethyl) aniline, N, N-bis (ß-hydroxyethyl) aniline , N-ethyl-N- (ß-methoxyethyl) aniline, N-ethyl-N- (ß-phenoxyethyl) aniline, N-ethyl I-N- (ß-cyanoethyl) aniline, N-ethyl-N- ( ß-phenylethyl) aniline, N-ethyl-N- (ß-phenylethyl) -m-toIuidin, N-ethyl-N- (ß-acet-65 oxyethyl) -m-toluidine, N-ethyl-N- (ß -benzoyloxyäthyl) -m-to-luidin, N, N-bis- (ß-äthoxycarbonyläthyI) -aniline, N, N-bis- [ß- (ß'-methoxyäthoxycarbonyl) -ethyl] -aniline, N-ethyl-N - (ß-chloroethyl) aniline, N, N-diethyl-m-aminoacetanilide, N, N-di-

3rd

631198

ethyl-m-aminobenzanilide, N-benzyl-2-methoxy-5-methylaniline, N- (p-chlorobenzyl) -2-methoxy-5-methylaniline, N, N-di-ethyI-2-methoxy-5- acetylaminoaniline, N-benzyl-o-chloroaniline and N, N-diethyl-m-tosyIaminoaniIin.

The reactions leading to the formation of the dyes according to the invention can be carried out using conditions which have been described in detail in the prior art for such reactions. Similarly, the dyes can be isolated by known methods; as in the case of other dyes which contain sulfo groups, it is often expedient to isolate and use the dyes in the form of their water-soluble salts, in particular their alkali metal or ammonium salts, preferably the sodium salts. Of course, the invention relates both to the free acids and to their salts.

The dyes according to the invention are suitable for application to polyamide textiles, such as wool and silk, but in particular to synthetic polyamide textiles, e.g. Nylon 66, Nylon 6 and Nylon 11, using any known general method for applying acid dyes to such materials. The dyes provide a large variety of shades with a high fastness to wet treatments and light.

The following examples, in which all parts and percentages are by weight, illustrate the invention.

example 1

0.8 parts of sodium nitrite are dissolved at 25 to 35 ° C in 10 parts of 98% sulfuric acid, whereupon the solution is cooled to 0 ° C. 2.3 parts of 2-amino-1,3-benzothiazole-5-sulfonic acid are added with vigorous stirring; the temperature is maintained at 0 ° C during the addition of 12.5 parts of water. The mixture is stirred for a further 2 hours at 0 ° C., whereupon the excess nitrous acid present is destroyed by adding sulfamic acid.

The suspension of the diazonium salt is stirred with a mixture of 2.11 parts of N-ethyl-N-benzyl-aniline and

Given 100 parts of water. After stirring for a further 2 hours, the dye, which is in the form of the free sulfonic acid, is isolated by filtration, washed acid-free with water and then converted into the sodium 5-trium salt by treatment with sodium hydroxide. It dyes synthetic polyamide fibers or fabrics from a neutral or weakly acid dyeing liquor in clear red shades with good to very good fastness properties.

The 2-amino-1,3-benzthi-10 azole-5-sulfonic acid used in this example is produced as follows:

24 parts of the sodium salt of 4-amino-3-nitrobenzenesulphonic acid are dissolved in 125 parts of 1-molar sulfuric acid with stirring, whereupon the solution is cooled to 0 ° C. and diazotized by slowly adding 2-molar sodium nitrite solution. Then 15 parts of sodium acetate are added; the mixture is added with stirring to a solution of 15.2 parts of ammonium thiocyanate and 0.5 part of cuprothiocyanate in 200 parts of water. The evolution of nitrogen ceased after 2 hours and no diazo-20 nium can be detected in the reaction mixture. The whole mixture is then added to a mixture of 50 parts of iron filings, 100 parts of water and 1 part of 36% hydrochloric acid, which has been heated to 95 ° C. for 30 minutes with stirring, followed by a further 2 hours at 90 to 95 ° C stirs. The mixture is then made alkaline by adding 4 parts of sodium carbonate and filtered. The clear filtrate is acidified by adding hydrochloric acid and the precipitate thus formed is isolated by filtration, washed with water and dried at 120 ° C.

30th

Further valuable dyes are obtained when the diazo component is reacted with the coupling components listed below in the manner given in Example 1, the coupling conditions being modified in the manner required in accordance with the type of coupling component. The dyes dye polyamide textiles in the specified colors.

example

Coupling component

hue

2nd

N-ethyl-N- (n-butyl) -m-toluidine ruby red

3rd

N-benzylaniline red

4th

N-ethyl-N- (o-chlorobenzyl) -m-toluidine bluish red

5

N-benzyl-2-methoxy-5-methylaniline ruby red

6

N-ethyl-N- (ß-benzoyläthyl) -aniline red

7

Diphenylamine bluish red

8th

N-benzyl-o-chloroaniline orange

9

2,6-diaminopyridine orange

10th

Yellow l-phenyl-3-methyl-5-aminpyrazole

11

2-phenylindole orange

12

N-ethyl-N-benzyl-m-toluidine bluish red

13

N-benzyl-m-toluidine red

14

N-ethyl-N-benzyl-2-methoxy-5-methyl-aniline ruby red

15

N-methyldiphenylamine bluish red

16

N, N-diethyl-m-toluidine bluish red

17th

N, N-diethyl-m-aminoacetanilide ruby red

18th

N, N-diethyl-m-aminobenzanilide ruby red

19th

N, N-diethyl-m-anisidine bluish red

20th

N, N-diethyl-m-chloroaniline red

21st

N, N-diethyl-m-bromoaniline red

22

N- (o-chlorobenzyl) -2-methoxy-5-methyl-aniline ruby red

23

N- (o-chlorobenzyl) aniline scarlet

24th

N-ethyl-N- (ß-phenylethyI) -aniIin bluish red

25th

N-ethyl-N- (ß-phenoxyethyl) aniline bluish red

26

N-ethyl-N- (ß-acetoxyethyl) aniline bluish red

27th

N, N-bis (ß-acetoxyethyl) -m-toluidine red

28

N, N-bis (ß-benzoyloxyäthyI) aniline red

631198 4

example

Coupling component

hue

29

N, N-bis (β-benzoyloxyethyl) -m-toluidine red

30th

N-ethyl-N- [ß- (4-tert-butylphenoxy) ethyl] aniline red

31

N-ethyl-N- [ß- (4-bromophenoxy) ethyl] -aniIin red

32

N-Ethyl-N- [ß- (2-ehlorphenoxy) ethyl] aniline red

33

N-ethyl-N-fß- (4-chlorophenoxy) ethyl] aniline red

34

N, N-bis (ß-phenylethyl) -m-toluidine ruby red

35

N-ethyl-N- (ß-hydroxyethyl) -m-toluidine ruby red

36

N, N-bis (ß-hydroxyethyl) -m-toluidine ruby red

37

N- (ß-cyanoethyl) -N- (ß-hydroxyethyl) -m-toluidine red

38

N-ethyl-N- (ß-chloroethyI) -m-toluidine red

39

N, N-bis (ß-cyanoethyl) aniline orange

40

2-methyl indole yellow

41

1 -phenyl-3-methylpyrazol-5-one yellow

42

1 -phenyl-3-carboethoxypyrazol-5-one yellow

43

l-phenyl-3-carbamoylpyrazol-5-one yellow

44

3-cyano-4-methyl-2,6-dihydroxypyridine greenish yellow

45

3-CarbamoyI-4-methyl-2,6-dihydroxy-pyridine greenish yellow

46

l-ethyl-3-cyano-4-methyl-6-hydroxy-pyrid-2-one greenish yellow

47

l-butyl-3-cyano-4-methyl-6-hydroxy-pyrid-2-one greenish yellow

Claims (5)

631198 PATENT CLAIMS 1. Water soluble monoazo dyes in the form of the free acid of the formula: HOjS. N, = N E correspond, in which E means the rest of a coupling component which is free of sulfo groups. 2. Water-soluble monoazo dyestuffs according to Claim 1, characterized in that E denotes the remainder of a coupling component of the pyrazolone, aminopyrazole, 2,6-dihydroxypyridine, 2,6-diaminopyridine, indole or arylamine series. 3. Water-soluble monoazo dyes according to claim 2, characterized in that they have the formula: H03S. N == N correspond, in which R1 is hydrogen or optionally substituted alkyl, R2 is hydrogen, optionally substituted alkyl, optionally substituted aryl or cycloalkyl, R3 is hydrogen, halogen, lower alkyl or lower alkoxy and R4 is hydrogen, halogen, lower alkyl, lower alkoxy or acylamino . 4. A process for the preparation of water-soluble monoazo dyes according to claim 1, characterized in that diazotized 2-amino-l, 3-benzothiazole-5-sulfonic acid is coupled with a coupling component containing no sulfo groups. 5. Water-soluble monoazo dyes, prepared by the process according to claim 4.