Patent GB-437283-A (GB)
Title: Manufacture of dyestuffs of the dioxazine series and of intermediate products therefor
IPC: C09B19/02
Filed: 1934-04-26
Abstract: Dioxazines suitable as pigments dyes for colour lakes and/or colouring wallpaper, paper and caoutchouc are obtained by condensing at a temperature above 120 DEG  C., a 1 : 4-benzoquinone with an amine having three condensed nuclei (other than an amine of the anthracene series), but not containing nitrogen in cyclic union.  An oxidizing agent, a metal chloride or an acylating agent may be used to assist the condensation.  By sulphonating the dioxazines, dyestuffs suitable for dyeing animal, vegetable and artificial fibres are obtained.  The barium and calcium salts of the sulphonic acids are pigments.  The dioxazines may be obtained in two stages by condensing the benzoquinone in a solvent below about 120 DEG  C. with the amines above defined, and then heating the resulting intermediate product in a high boiling solvent to above 120 DEG  C.  In examples: (1) an intermediate obtained by heating 2-aminofluorene with chloranil in the presence of sodium acetate and alcohol is converted into the dyestuff by further heating in glacial acetic acid with sodium bichromate; on sulphonation with oleum, a dyestuff is obtained dyeing animal, vegetable and viscose fibres violet shades; (2) an intermediate obtained from 2-amino-diphenyleneoxide and chloranil is further condensed by heating with nitrobenzene and m-nitrobenzenesulphochloride, and is finally sulphonated; (3) a pigment is obtained directly by heating 3-aminophenanthrene and chloranil in nitrobenzene, and is then sulphonated; (4) an intermediate obtained from benzoquinone and 2-aminofluorenone is further condensed by heating with chlornaphthalene and m-nitrobenzenesulphochloride; (5) an intermediate obtained from chloranil and aminodiphenylenedioxide is further condensed by heating with nitrobenzene and ferric chloride; (6) an intermediate obtained from aminodiphenylenedioxide and toluquinone is further condensed by heating with nitrobenzene.  The use of amino derivatives of diphenylenesulphide, xanthone and thioxanthone is mentioned. Specifications 8886/12, [Class 2 (iii)], and 387,565 (as open to inspection under Sect. 91) are referred to.  2-Aminofluorene is obtained by nitrating fluorene with a nitric-acetic acid mixture and reducing with zinc dust and calcium chloride in alcohol. 2-Aminofluorenone is obtained by oxidizing 2-nitrofluorene in glacial acetic acid with sodium bichromate and reducing with ammonium sulphide in alcohol.  2-Aminodiphenylenesulphide is obtained by nitrating diphenylenesulphide and reducing.  Aminodiphenylenedioxide is obtained by treating diphenylene dioxide in glacial acetic acid with nitrogen oxides and reducing the nitroso-compound with tin, glacial acetic acid and hydrochloric acid.  Samples have been furnished under Sect. 2 (5) as follows: (a) the intermediate obtained in example 1 is further condensed to form a pigment by heating in nitrobenzene with benzoyl chloride and pyrolusite; (b) the pigment is sulphonated; (c) the sulphonic acid is converted into its calcium and barium salts; (d) an intermediate obtained from a 2-aminofluorene and 2 : 3 : 5 : 6-tetrabrom-1 : 4-benzoquinone is further condensed to a dioxazine; (e) the pigment dyestuff (d) is sulphonated; (f) an intermediate is obtained from 2-aminofluorene and 2 : 3 : 5 : 6-tetrabrom-1 : 4-benzoquinone.  The Specification as open to inspection under Sect. 91 comprises the use, in the condensation of a 1 : 4-benzoquinone substituted in the nucleus by an aryl group, e.g., 3 : 6-di-p-tolyl-1 : 4-benzoquinone and includes an example in which chloranil is condensed with b -anthramine in the presence of nitrobenzene and 2 : 4-dinitrophenol.  This subject-matter does not appear in the Specification as accepted.