307,947. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). Sept. 12, 1927. Samples furnished. Dibenzanthrone derivatives.-Vat dyestuffs are obtained (1) by condensing one molecular proportion of an aromatic or heterocyclic compound containing two or more negative substituents in the nucleus with two or more molecular proportions of an aminodibenzanthrone or aminoisodibenzanthrone ; (2) by condensing equimolecular proportions of an aminodibenzanthrone or amino. isodibenzanthrone and an aromatic or heterocyclic compound containing one or more negative substituents in the nucleus; or (3) by replacing the negative substituents in a mononuclear heterocyclic compound partly by the aminodibenzanthrone or aminoisodibenzanthrone radical and partly by the radical of an aminoanthraquinone or other amino, hydroxy, or mercapto compound. The condensations are effected in solvents or diluents of high boiling-point, such as nitrobenzene or naphthalene, preferably in the presence of catalysts such as copper salts and acid-fixing agents such as sodium acetate. The negatively-substituted aromatic or heterocyclic compounds employed may be derived from benzene, naphthalene, anthracene, phenanthrene, perylene, pyrene, dibenzpyrene, anthraquinone, anthranthrone, pyranthrone, dibenzanthrone, msbenzdianthrone, ms-naphthodianthrone, allo-msnaphthodianthrone, ms-anthradianthrone, anthraquinoneacridone, indigo, thioindigo, &c. Chloranil and picryl chloride are suitable benzene derivatives; heterocyclic compounds mentioned are cyanuric chloride, 2 : 4-dihalogenquinazoline; 2 4 : 6-trihalogenpyrimidine, 2-alkyl- or 2-aryl- 4 : 6-dihalogentriazine, 2-chlorbenzotriazole, or 2 4-dichlorquinoline. In the case of the condensation of an aminodibenzanthrone with a nitrodibenzanthrone, the process may be effected by treating the nitrodibenzanthrone with an amount of reducing-agent, such as hydrazine, sufficient only to reduce a portion of the nitro body, and then effecting condensation of the reduced and non-reduced portions of the mixture; any excess of amino body remaining can be simultaneously or subsequently condensed with a negatively-substituted aromatic compound as described above. According to examples, condensation products are prepared from the following parent materials :-(1) Aminodibenzanthrone (1 mol.) and 1-chloranthraquinone (1 mol.) (dyes grey to black); (2) aminodibenzanthrone (1 mol.) and 2-chlaranthraquinone (1 mol.) (dyes blueblack); (3) aminodibenzanthrone (2 mols.) and dibromanthanthrone (1 mol.) (dyes grey to black); (4) aminodibenzanthrone (2 mols.) and trichlaranthraquinoneacridone (1 mol.) (dyes greenish-black): (5) aminodibenzanthrone (1 mol.) and dibromisodibenzanthrone (1 mol.) (dyes blueblack) ; (6) aminodibenzanthrone (2 mols.) and dichlor-allo-ms-naphthodianthrone (1 mol.) (dyes black); (7) aminodibenzanthrone (3 mols.) and tribrompyranthrone (1 mol.) (dyes grey to black) ; (8) aminodibenzanthrone (1 mol.) and nitrodibenzanthrone (1 mol.) (dyes grey to black); (9) nitrodibenzanthrone (4 mols.) reduced in situ by hydrazine hydrate, and tetrabrompyranthrone 1 mol.) (dyes grey to black): (10) aminodibonzanthrone (3 mols.) and tribrompyranthrone (1 mol.) (dyes grey-brown to black): (11) aminodibenzanthrone (1. mol.) and 1-nitronaphthalene (1 mol.) (dyes bluish-grey to black): (12) aminodibenzanthrone (2 mols.) and 1 : 5-dinitroanthraquinone (1 mol.) (dyes bluish-grey to black); (13) aminodibenzanthrone (3 mols.) and tetrabrompyranthrone (1 mol.) (dyes grey to black); (14) aminodibenzanthrone (1 mol.) and chloranil (1 mol.) (dyes blue); (15) aminodibenzanthrone (2 mols.) and chloranil (1 mol.) (dyes blue); (16) aminodihenzanthrone (3 mols.) and cyanuric chloride (1 or 2 mols.) (dyes green-blue); (17) aminodibenzanthrone (1 mol.), 1-aminoanthraquinone (2 mols.), and cyanuric chloride (1 mol.) (dyes yellow-green); (18) aminodibenzanthrone (2 mols), 1-amino-4-methoxyanthraquinone (1 mol.), and cyanuric chloride (1 mol.) (dyes blueblack); (19) nitrodibenzanthrone, partially reduced by hydrazine hydrate, and the resulting mixture condensed (dyes grey to black): (20) nitrodibenzanthrone, partially reduced by hydrazine hydrate, the resulting mixture condensed, and the product further condensed with 1 : 5- dichloranthraquinone (dyes blue-grey to black). The aminodibenzanthrones employed are prepared by reducing the nitrodibenzanthrone described in Specification 1818/05 or the purified nitrodibenzanthrone described in Specification 220,212, or by the reaction of hydroxylamine on dibenzanthrone; the aminoisodibenzanthrone is prepared by nitrating isodibenzanthrone with nitric acid in nitrobenzene and reducing the product; the dibromisodibenzanthrone is prepared by brominating isodibenzanthrone in chlorsulphonic acid in presence of antimony; the dibromanthanthrone is prepared as described in Specification 260,998; the dichlor - allo -msnaphthodianthrone is prepared as described in Specification 303,184. Specifications 205,525, 248,519, 285,502 and 307,364 also are referred to. Tribrompyranthrone and tetrabrompyranthrone are prepared by brominating pyranthrone in chlorsulpbonic acid in the presence of sulphur. Trichloranthraquinoneacridone is prepared by condensing 1 - chloranthraquinone - 2 - carboxylic acid with p-chloraniline, closing the acridone ring, and chlorinating the product with sulphuryl chloride in nitrobenzene. Reference has been directed by the Comptroller fo Specification 26551/12.