522,657. Dyes ; dyeing. SOC. OF CHEMICAL INDUSTRY IN BASLE. Dec. 19, 1938, Nos. 36897 and 36898. Convention dates, Dec. 20, 1937, and Nov. 29, 1938. [Classes 2 (iii) and 15 (ii)] Vat dyes are made by the action of acid condensing agents on compounds of the general formula R 1 -NH-R 2 -NH-R 3 , where R 2 is a naphthalene radicle which contains at least one of the imino groups in #-position, R 1 and R 3 are residues of vattable compounds free from sulphonic groups, and at least one of the positions in the residues R 1 , R 3 adjacent to the imino groups is unsubstituted. In a modification, compounds of the general formula R 1 -NH-R 2 -X, where X is a halogen atom, are treated with acid condensing agents, and the products are reacted with amines containing the residue of a vattable compound and further condensed, if desired. The parent materials may be made by the process of Specification 522,658. The residues R 1 , R 3 may be the same or different and may be anthraquinone radicles or more highly condensed ring systems, e.g., the residues of 1- aminoanthroquinone, 1-aminoarylaminoanthroquinones, aminoacylaminoanthraquinonessuch as 1-amino-4- or -5-benzoylaminoanthraquinone, 1-amino-5-benzoylamino-8-methoxyanthraquinone, 1-amino-5:8-benzoylamino, anthraquinone, 1-amino-5-acetyl, -pyridoyl, or -cinnamoyl-aminoanthraquinones, 1-aminoanthraquinonoylaminoanthraquinones, and the amino derivatives of dibenzanthrones, isodibenzanthrones, pyranthrone, anthrapyrimidines, anthropyrimidones, isothiazoleanthrones, pyrazoleanthrones, and anthraquinone-acridones. As acid condensing agents, aluminium chloride, acetyl chloride, chlorsulphonic acid and concentrated sulphuric acid may be used. The treatment with acid condensing agents is advantageously followed by an oxidizing treatment, e.g. by means of a nitrite, hypochlorite perborate or by passage of air. The products are vat dyes for wool, silk, cotton and regenerated celluloses, and may be used in alkaline hydrosulphite baths or in the form of their leuco esters. In examples, the following substances are treated with sulphuric acid or aluminium chloride : the condensation 'products from 2:6-dibronnaphthalene and 1-amino-4- or 5-benzoylaminoanthraquinone (2 mols.), 1-aminoanthraquinone (2 mols.), 1-amino-5-acetylaminoanthraquinone (2 mols.), 4- or -5- aminoanthraquinone-2:1 (N)-benzocridone (2 mols.), 5- amino-1:9-anthrapyrimidine (2 mols.), 1-amino- 4- and -5-benzoylaminoanthraquinones (1 mol. of each, either simultaneously or successively), 1-amino-5-benzoylaminoanthraquinone (1 mol.) and 4-amino-1:9- anthrapyrimidine (1 mol.), 5- aminoanthraquinone-2:1-(N)-benzacridone (1 mol.) and 1-aminoanthraquinone (1 mol.) and aminodibenzanthrone (2 mols), and the con densation products from 1:6-dibromo-2-methoxynaphthalene and 1-amino-4-or 5-benzoylaminoanthraquinone (2 mols.), and 1-aminoanthraquinone (2 mols.). In a further example, the condensation product of 2:6-dibromnaphthalene and 1-amino-5-benzoylaminoanthraquinone (1 mol.) is treated with sulphuric acid, condensed with a further mol. of 1-amino-5- benzoylaminoanthraquinone, and again treated with sulphuric acid. Examples are also given of the dyeing of cotton in an alkaline hydrosulphite vat with some of the products. Specification 498,602 also is referred to.