Patent GB-472125-A (GB)
Title: Manufacture of dyestuffs
IPC: C09B57/08
Filed: 1936-03-16
Abstract: Dyes are made by reacting a nuclearly-halogenated naphthalene-1.4.5.8-tetracarboxylic acid or the anhydride or an imide thereof with ammonia or an amine, such as an aliphatic or aromatic amine, so that the nuclear halogen is wholly or partly exchanged for the radical of an amine or ammonia.  From 2 : 6-dichlornaphthalene-1.4.5.8-tetracarboxylic acid and aniline, there may be obtained 2.6-dichlornaphthalene-1.4.5.8-tetracarboxylic acid diphenylimide and the corresponding 2-anilino-6-chlor or 2.6-dianilino derivatives, according to the quantity of aniline used. Unsubstituted diimides or dialkylimides may be used and the aryl nuclei of the amines may contain substituents such as alkyl, hydroxyl, carboxyl.  Aminosalicylic acids may be used as amines, when the dyestuffs produced are capable of being chromed.  The products or intermediate products may be sulphonated.  Halogenated naphthalene 1.4.5.8-tetracarboxylic acids may be obtained by direct halogenation of naphthalene-1.4.5.8-tetracarboxylic anhydride or by oxidizing decomposition of polyhalogen - pyrenes. Solvents, acid-binding agents and catalysts which promote the splitting-off of hydrogen halide may be used, if desired with application of pressure.  In examples, 2-chloronaphthalene-1.4.5.8-tetracarboxylic acid anhydride is heated with excess p-toluidine or ethanolamine to give 2 - (p - toluidino) - naphthalene - 1.4.5.8 - tetracarboxylic acid di-p-tolylimide and 2-hydroxyethylaminonaphthalene-1.4.5.8 - tetracarboxylic acid dihydroxyethylimide (red tints on wool) respectively, or with less p-toluidine to give the di-p-tolylimide, which is then reacted with cyclohexylamine (bluish red shades on wool after sulphonation), a -aminoanthraquinone (pink shades on cotton), or 1-amino-5-benzoylaminoanthraquinone (yellow - red tints on cotton); 2.6-dichlornaphthalene-1.4.5.8-tetracarboxylic acid anhydride or the mixture probably of 2.6- and 2.7-dichloronaphthalene-1.4.5.8-tetracarboxylic acids obtainable according to Specification 421,813 by oxidizing decomposition of hexachlorpyrene, is reacted with excess aniline or p-toluidine (greenish-blue on wool after sulphonation); 2.6-dichlornaphthalene-1.4.5.8-tetracarboxylic acid or its anhydride is reacted with aniline to give the diphenylimide which is reacted with 1-aminoanthraquinone (grey-blue tints on cotton), or with ammonia to give the di-imide and then with a -naphthylamine (blue tints on wool after sulphonation), or with methylamine to give the dimethylimide and then with p-toluidine to replace one chlorine atom (bordeaux-red on wool after sulphonation) or both chlorine atoms (blue tints on wool after sulphonation); 2.7-dichloronaphthalene-1.4.5.8-tetracarboxylic acid anhydride (prepared by dichlorination of acenaphthalic acid anhydride followed by oxidation) is heated with excess p - toluidine; 2 - bromonaphthalene - tetracarboxylic acid anhydride (obtained by oxidation of 3-bromoacenaphthalic acid) is heated with excess aniline to give the diphenylimide, which is then reacted with o- or p-phenylene diamine.  Specifications 400,069 and 414,230 also are referred to.