Patent GB-325797-A (GB)
Title: Improvements in the manufacture and production of anthanthrone derivatives
IPC: C09B3/64
Filed: 1928-08-25
Abstract: 325,797. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). Aug. 25, 1928. Divided on 323,750. Anthanthrone derivatives are prepared by replacing the nitro group in mononitroanthanthrones, or partially or wholly replacing the nitro groups in polynitroanthanthrones by residues other than amino groups. The nitro group or groups may be replaced by halogen by heating the nitroanthanthrone with halogen or a halogenating agent, under pressure if desired, and preferably in an organic diluting medium. With drastic conditions further halogenation of the anthanthrone derivative may occur, while on the other hand the partial replacement of nitro groups by halogen in polynitroanthranthrones is effected by the action of benzoyl halides in the absence of any solvent, or of calculated amounts of halogen in presence of organic solvents. Or the nitroanthanthrones are first reduced to the corresponding amino derivatives, the latter diazotized and thus replaced by halogen, hydroxy, cyano, carboxylic, mercapto or thiocyano group or groups. Partial replacement of nitro groups in polynitroanthanthrones according to this latter process is effected by partial reduction of the polynitro derivative by means of the calculated amount of hydrazine or glucose and replacement of the amine group present by the above monovalent substituents. The following derivatives are prepared in examples, the dyeing shades on cotton being indicated in brackets : (1) Monochloranthanthrone (orange-yellow) by heating with benzoyl chloride the mononitro derivative obtained by nitrating anthanthrone in nitrobenzene with 96 per cent nitric acid ; using benzoylbromide the monobromo derivative is obtained; a dichloranthanthrone (orange) is obtained by treating this mononitro derivative in trichlorbenzene with chlorine and a dibromoanthanthrone (orange-red) by treating in nitrobenzene and in presence of iron, with bromine. (2) Dichloranthanthrone (yellow-orange) by chlorinating in trichlorbenzene the dinitro derivative obtained by dissolving anthanthrone in 96 per cent nitric acid, or by prolonged boiling of this derivative with benzoyl chloride, the presence of iodine as catalyst being optional; by a less drastic treatment with benzoyl chloride a monochloromononitroanthanthrone (grey) is also obtained. (3) Tetrachloranthanthrone by chlorinating in trichlorbenzene the tetranitro derivative obtained by treating anthanthrone with a mixture of nitric and sulphuric acids; by boiling this tetranitro derivative with benzoyl chloride monochlortrinitroanthanthrone (grey) is obtained. (4) The monoaminoanthanthrone obtained by reducing the mononitro derivative of (1) is converted by way of the diazo compound to monohydroxyanthanthrone, and from this monomethoxyantbanthrone (red), monoethoxyanthanthrone (red), and #-chlorethoxyanthanthrone (red); monocyanoanthanthrone (yellow) and by hydrolysis, anthanthrone monocarboxylic acid; monothiocyanoanthanthrone, monobromanthanthrone (orange-yellow, monoiodoanthanthrone (orange), and monomercaptoanthanthrone by the action of potassium hydrosulphide or of thiourea; the latter compound is easily oxidized to the dianthanthronyl disulphide (brown). (5) The diaminoanthanthrone obtained by reduction of the dinitro derivative of (2) is similarly converted to dihydroxyanthanthrone and thus a. dialkoxyanthanthrone (blue-red), diiodoanthanthrone (blue-red), dichloranthanthrone, dibromanthanthrone (orange-red), dicyanoanthanthrone and dimercaptoanthanthrone by the action of potassium hydrosulphide Other derivatives mentioned as valuable dyestuffs are the carboxylic esters of anthanthrone and the ethers of hydroxyanthanthrones, for instance, the ethylene, chlorethylene and phenyl ethers (yellowred to red-blue).