DE955178C - Process for the production of dyes - Google Patents

Description

Process for the preparation of dyes It is known aromatic o-Dinitrile in the absence of metals with less than the equivalent amount of Ethanolamines or of primary or secondary amines of the basicity constant K = z - i o-4 to 2 - io-3 to be heated to around 17o to 23o ° (cf. the American Patent specifications z 155 054 or. 2485 i67). This is created without installing the added Amines that only play a catalytic role are the same blue phthalocyanines as in the absence of the amines.

It has now been found that new, valuable, not the phthalocyanine series Associated dyes are obtained when aromatic o-dinitriles with aminothiazoles heated.

The implementation kan: ri in the melt by simply baking the Starting materials are made at temperatures of about 150 to 2oo ° or else by heating the starting materials in the presence of a high-boiling solvent, such as nitrobenzene, trichlorobenzene, o-dichlorobenzene and dg1. An addition of anhydrous Alkali acetates, such as sodium or potassium acetate, usually have a beneficial effect the yield. In general, one mole of the dinitrile and one mole of the aminothiazole Vmsetzen, but it is often advisable to choose the amount of aminothiazole somewhat larger than the amount of dinitrile.

Valuable, generally red pigment dyes are obtained which are distinguished by excellent fastness properties and great color strength. The yield or the color strength of the dyes obtained can be increased significantly if they are used; expediently in the presence of a grinding aid such as sodium chloride; married. The formation of the new dyes probably takes place according to the following reaction scheme: The parts mentioned in the following examples are parts by weight.

Example i An intimate mixture of 28 parts of phthalonitrile and 36 parts of 2-amino-6-methoxy-benzothiazole are added, advantageously with stirring, for 2 hours heated to 155 to 16o °. After cooling, the raw product is treated with acetone, and 16 parts of a yellowish red dye are obtained as residue, which is Excellent as a pigment for a variety of purposes.

Beis-piel2 An intimate mixture of 28 parts of phthalodine, nitrile, 36 Parts of 2-amino-6-methoxy-benzothiazole and 100 parts of anhydrous sodium acetate Heated to 155 to 16o ° for 2 hours. After working up, 36 parts of one are obtained yellowish red dye.

Example 3 An intimate mixture of 28 parts of phthalonitrile and 72 parts Parts of 2-amino-6-methoxy-benzothiazole are heated to 155 to 160 ° for 2 hours. To After working, 50 parts of the yellowish red dye are obtained.

Example q.

28 parts of phthalonitrile and 72 parts of 2-amino-6-methoxy-benzothiazole will. heated in 58o parts of trichlorobenzene for 2 hours to 180 to igö °. After this Suctioning off and washing with acetone gives 60 parts of a yellowish red dye. Example 5 10 parts of 3,4-dicyandiphenyl and 13 parts of 2-amino-6-methoxy-benzothiazole are boiled in 180 parts of trichlorobenzene for 3 hours. One receives after washing of the precipitated product with acetone 13 parts of a brown-red dye.

Example 6 21 parts of o-phthalodolonitrile are mixed with 49 parts of 2- (q .'-aminophenyl) -6-methyl-5 (7) -saifobenzthi azole q. Melted at about 2q.0 ° for hours. The melt is boiled with water and acetone. 39 parts of a yellow-brown remain as residue Condensation product.

Example 7 14 parts of o-phthalonitrile are mixed with 20 parts of 2-amino-6-methylbenzothiazole in zoo parts of trichlorobenzene with stirring and reflux q. Simmer for hours. The residue is filtered off with suction and purified with acetone. There will be 2o parts of one orange-yellow powder obtained. The dye goes when rubbed with zinc oxide and Linseed oil turns a bright red.

Example 8 A mixture of 1q. Parts of phthalonitrile, 15 parts of 2-aminothiazole and-200 parts of trichlorobenzene are heated to boiling for 3 hours with stirring. To the cold separate from the Implementation mixture io parts of a yellow-brown dye. Alus of the mother liquor is obtained by concentrating more i i parts.

Claims (2)

PATENT CLAIMS: i. Process for the preparation of dyes, characterized in that aromatic o-dinitriles are heated with aminothiazoles. 2. The method according to claim i, characterized in that the reaction is carried out in the presence of anhydrous alkali acetates. Contemplated publications: USA. Patents No. 2155054, 2485 i67..