DE1288212B - Process for the preparation of monoazo dyes - Google Patents

Description

From the German patent 899 537 example 2 is the monoazo dye of the formula

HO COOH

, C-N-

H ₂ NO ₂ S

N = N-C

C = N

CH ₃

Cl

known, the wool in reddish-yellow shades of good authenticity properties after the single bath chrome plating process colors.

It has now surprisingly been found that monoazo dyes, which instead of l- (3'-chlorophenyl) -3 -methyl-pyrazolone- 5, 1 -aryl- 5 - aminopyrazole, in which the aryl radicals are unsubstituted mono- or binuclear aromatic radicals, as coupling components contain, dyed on wool according to the single-bath chrome longitudinal process, an essential result in greater deepening of color and, also dyed on wool, have better migration.

The invention relates to a process for the preparation of valuable monoazo dyes, thereby characterized in that 1 mole of the diazo compound is obtained from one in the ortho position to the amino group substituents enabling metal complex formation, containing aminobenzene, which is replaced by halogen atoms (preferably chlorine or bromine), nitro, acetylamino, carbomethoxyamino, carbethoxyamino, methyl, Ethyl-, tert-butyl-, methoxy-, sulfonic acid amides, sulfonic acid methylamide, Sülfonsäuredrniethylamid-, Sülf onic acid - (2'-hydroxy) - ethylamide -, ..- sulfonic acid di (2'-hydroxyäthyI) -amid-, Sulfonic acid hydroxypropylamide, sulfonic acid methoxypropylamide, sulfonic acid phenylamide, Suhonic acid (2'-carboxy) phenylamide, methylsulfonyl and ethylsulfonyl groups are further substituted can be, with 1 mole of one in the 3-position unsubstituted or methylated 1-aryl-5-aminopyrazole, in which the aryl radicals are one or unsubstituted are binuclear aromatic residues, couples.

The substituent of the diazo component which enables metal complex formation is preferably one Hydroxy, a methoxy or a carboxy group,

The diazotization of the aminobenzenes according to the definition is carried out in the usual way at from 0 to 5 ° C. The coupling of the diazo compounds obtained with. the azo components is carried out at 10 to 40 ⁰ C in a weakly acid medium, optionally in the presence of pyridine. The monoazo dyes formed are, if necessary, separated from the coupling materials by means of sodium chloride or acid, then filtered off, washed and dried. "" - """

The new monoazo dyes dye wool, silk, leather and synthetic polyamide fibers according to the Post-chroping or single-bath chroming process in orange, brown to brown-red shades of good light and wet fastness properties. The colorations on the fiber can also be done with cobalt compounds metallize well.

In the following examples, parts are parts by weight and percentages are percentages by weight. The temperatures are given in degrees Celsius.

Example 1

26.4 parts of 2-ammo-1-hydroxybenzene-4-sulfonic acid phenylamide are dissolved with 8 parts of sodium hydroxide in 130 parts of water. To this are added 6.9 parts of sodium nitrite in'25 parts of water and pouring the obtained solution at a 5 ° temperature not exceeding in a mixture of 48 parts of concentrated \ hydrochloric acid and 100 parts of ice.

17.3 parts of 1-phenyl-3-methyl-5-aminopyrazole are in 18 parts of concentrated hydrochloric acid and 200 parts Dissolved water and added to the diazo suspension. After adding 50 parts of pyridine, the heated Coupling mass for 8 hours at 35 to 40 °. After the coupling is complete, the mixture is with concentrated hydrochloric acid acidified on Congo paper, whereupon the deposited dye is filtered off with Water is washed and dried.

Example2

2-aminobenzene-1-carboxylic acid is diazotized and If it couples with 1-phenyl-3-methyl-5-aminopyrazole, a dye is obtained, the color of which has been chromed is orange on wool and has very good properties. '

Example3

20.2 parts of 2-amino-l-hydroxybenzene-4-sulf onsäuremethylamid are dissolved 30 ° / _o hydrochloric acid and 500 parts of water in einem- mixture of 20 parts. The solution is cooled to 0 ° and a solution of 6-9 parts of sodium nitrite in 20 parts of water is slowly added at 0 to 5 °. After some time, the diazotization is complete; the diazo suspension is poured into a solution of 17.3 parts of l-phenyl-S-methyl-S-amino- • pyrazole in 18 parts of concentrated hydrochloric acid and 200 parts of water, 70 parts of pyridine are added to the coupling mixture, and it is heated to 35 ° stir it for 8 hours at 35 to 40 °. The monoazo dye formed is through. Acidification with concentrated hydrochloric acid deposited, 'then filtered off, washed with cold water, dried and pulverized.

It is a brown powder that can be dissolved in water with the addition of a little soda, bicarbonate or ammonia is soluble and wool is brownish-tinged red after the post-chrome plating or single-bath chrome plating process light- and wet-fast tones.

Claims (1)

Claim: A process for the preparation of monoazo dyes, characterized in that 1 mol of the diazo compound is obtained from an aminobenzene containing a substituent in the ortho position to the amino group capable of forming metal complexes, which is replaced by halogen atoms, nitro-jAcetylamino- ^ carbomethoxyamino-jCarboethoxyamino-, methyl-, , tert-butyl, methoxy, sulfonic acid amide, sulfonic acid methyl amide, sulfonic acid dimethyl amide, sulfonic acid - (2 '- hydroxy) - ethyl amide, sulfonic acid - di - (2' - hydroxyethyl) amide, sulfonic acid hydroxypropyl amide, sulfonic acid methoxypropyl amide, sulfonic acid -, Sulphonic acid - (2 '- carboxy) - phenylamide, methylsulphonyl or ethylsulphonyl groups can be further substituted with 1 mol of an unsubstituted or methylated l-aryl-5-aminopyrazole in which the aryl radicals are unsubstituted or unsubstituted in the 3-position are binuclear aromatic residues, couples.