DE1205637B - Process for the preparation of basic azo dyes - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C09b

German KL: 22 a -1

Number: 1 205 637

File number: B 60588 IV c / 22 a

Filing date: December 22, 1960

Opening day: November 25, 1965

From British Patent 837 471 it is known that basic dyes are obtained if sulfonic acid group-free p-aminoazo dyes of the general formula

/ N

.N

HOOC

λ /

= N-R-N '

in which R is an ortho- or para-phenylene or naphthylene radical and Y and Z are, for example, hydrogen or alkyl radicals, decarboxylated by heating in a solvent and then with alkylating agents treated.

The dyes obtained by this process are particularly suitable for dyeing structures made of polyacrylonitrile and acrylonitrile copolymers.

It has now been found that yellow to orange basic azo dyes with excellent fastness properties can be obtained obtained when compounds of the formula

HOOC

N = N

N-X

C ₆ H ₅

wherein X denotes a hydrogen atom or an alkyl radical, decarboxylated by heating in the melt or advantageously in an inert solvent to temperatures up to 200 ^° C. or by heating in water up to 100 ^° C. and, optionally at the same time, reacted with alkylating agents.

For example, alkyl, aralkyl and cycloalkyl halides, such as methyl iodide, are used for the alkylation. Ethyl bromide. Benzyl chloride or dialkyl sulfates or sulfonic acid esters. One can do the alkylation Carry out the decarboxylation in one operation.

A starting dye containing the carboxyl group is known from French patent specification 1,153,239. It is obtained by coupling the diazo compound of 3-amino-5-carboxy-1,2,4-triazole with 1-methyl-2-phenylindole. Other methods of making basic
Azo dyes

Applicant:

Aniline & Soda Factory in Baden

Aktiengesellschaft, Ludwigshafen / Rhein

Named as inventor:

Dr. Helmut Pfitzner,

Dr. Hans Baumann, Ludwigshafen / Rhine

Starting compounds are obtained in the same way.

The cleavage of the carboxyl group can be carried out in the melt, but it is better through Heating in an inert organic solvent. The carboxyl group is particularly easy to pass through Split off the starting material by heating in an aqueous suspension.

The new dyes contain the cation of the general formula

/ N

C-N =

HC _x ^,
R.

wherein X is a hydrogen atom or an alkyl radical and R is an alkyl, aralkyl or a cycloalkyl radical means. They are suitable for dyeing textiles such as flakes, fibers, threads. Woven or knitted fabrics made from polyacrylonitrile or from copolymers of acrylonitrile with others Vinyl compounds.

Compared to the from British Patent 837 471, Example 1, known dye and one from the starting dye described on page 5, first formula, of French patent specification 1,153,239 available monomethylated dyestuff still containing carboxyl groups are distinguished by the

509 739/370

the present process obtainable dyes by better absorption on polyacrylonitrile and better reservation made of acetate silk.

The dyeings obtained are characterized by lively, strong tones and excellent fastness properties the end.

The parts mentioned in the examples are parts by weight. Percentages relate to percentages by weight.

IG

example 1

19.2 parts of 3-amino-1,2,4-triazole-5-carboxylic acid are dissolved in 200 parts of water with 13 parts of 50% strength sodium hydroxide solution. One gives 10.5 parts of sodium nitrite, cooled with ice to 0 ⁰ C and poured, with stirring, 60 parts of a hydrochloric acid lOnormaler. A warm solution of 30 parts of 2-phenylindole in 50 parts of dimethylformamide is allowed to flow into the diazo suspension from which excess nitrite has been removed. After the coupling has ended, the pH is buffered to 5 with sodium acetate. The mixture is filtered, the product under reduced pressure and dried at 6O ⁰ C in vacuo.

The powdered coupling product is stirred in 100 parts of dimethylformamide at 70 ⁰ C. 50 parts of dimethyl sulfate are allowed to flow in and the mixture is stirred at 110 to 125 ° C. for 3 hours. The cooled at 8O ⁰ C the reaction mixture to wear in 500 parts of ice water, treated with 130 parts of sodium chloride and filtered off the deposited dye. It is dried under vacuum at 8O ⁰ C and obtained 66 parts of the dye of the formula

with stirring, 120 parts of 10N hydrochloric acid. After the end of the diazotization, it is still removed existing excess nitrite with sulfamic acid and combined the diazo suspension with a finely divided Dispersion of 63 parts of 1-methyl-2-phenylindole in 320 parts of ice water.

After the coupling has ended, the reaction mixture is filtered off and stirred up again with 1000 parts of water. After addition of 50 parts lOnormaler hydrochloric acid is heated under stirring slowly to 80 ° C and upon release of the carbon dioxide development briefly to 90 ⁰ C. After cooling, blunts with 40 parts of sodium acetate in weakly acid to Congo from acidic reaction. The product is filtered off under reduced pressure. washes with water on the filter and dries in vacuo at 6O ⁰ C.

94 parts of this coupling product are ground with 12 parts of magnesium oxide and mixed with 600 parts of chloroform. 115 parts of dimethyl sulfate are allowed to flow in with stirring and the mixture is heated to the boil until a sample of the reaction mixture is uniform in the paper chromatogram. After adding 100 parts of water, the chloroform is distilled off, and a further 400 parts of water and 40 parts of 10N hydrochloric acid are added. The dye is precipitated by adding 30 parts of zinc chloride and 50 parts of sodium chloride. It is filtered under reduced pressure, washed on the filter with 10% sodium chloride solution and dried at 8O ⁰ C.

170 parts of the dye of the formula are obtained

CH ₃

Cl ^Θ

Cl ^e · ¹ Z ₂ ZnCl ₂

the reddish yellow dyeings on polyacrylonitrile materials with excellent fastness properties results.

B e i s ρ i e 1 2

27 parts of the coupling product prepared according to Example 1 and containing the carboxyl group are heated ^{to 110 ° C. in 300 parts of formamide with 60 parts of benzyl chloride for 5 hours.} When the alkylation has ended, the reaction mixture is subjected to steam distillation. The residue, which is plastic in the heat, solidifies after cooling. It is filtered off with suction, dried at 50 ° C. and 38 parts of a dye which is similar to the dye of Example 1 in terms of dyeing behavior are obtained.

Example 3

38.4 parts of 3-amino-1,2,4-triazole-5-carboxylic acid are dissolved in 500 parts of water with 25.5 parts of 50 percent sodium hydroxide solution. They are 21 parts of sodium nitrite, cooled with ice to 0 ⁰ C and poured polyacrylonitrile fibers from neutral or acidic bath in very light- and wet-fast colored yellow.

Claims (2)

Patent claims: 1. A process for the preparation of basic azo dyes, characterized in that that one compounds of the formula HOOC N _x H S / C ₆ H ₅ wherein X is a hydrogen atom or an alkyl radical, by heating in the melt or advantageously in an inert solvent 5 6 to temperatures up to 200 ° C or by heating the starting dye in aqueous Heating in water up to 100 ⁰ C decarboxylated engined suspension executes. and, optionally simultaneously, with alkylating agents Implements funds. Considered publications: 2. The method according to claim 1, characterized in that French patent specification no. 1153 239; indicates that the decarboxylation is carried out British Patent No. 837 471. When the application was announced, a coloring table with explanations was laid out. 509 739/370 11.65 © Bundesdruckerei Berlin