Patent GB-421611-A (GB)
Title: Manufacture of 4:8-dihydroxy-1:2:5:6-dibenzophenazines and azo-dyestuffs therefrom
IPC: C09B29/36
Filed: 1933-06-26
Abstract: 4 : 8-Dihydroxy-1 : 2 : 5 : 6-dibenzophenazines, of the formula <PICT:0421611/IV/1> in which the benzene nuclei not containing the hydroxy-groups may contain substituents, are manufactured by converting a 2-amino-3-hydroxynaphthalene, the hydrogen atom of which has been exchanged for a suitable radicle, e.g. an acyl or alkyl radicle, into the phenazine by oxidation and then splitting off the radicles linked to the oxygen of the original hydroxy-groups.  In examples: (1) 2-amino-3-[(3<1>-carboxybenzene - 1<1> - sulphoyl) - hydroxy] - naphthalene is heated with copper oxide in trichlorobenzene and the product is saponified with caustic soda and then acidified producing 4 : 8-dihydroxy-1 : 2 : 5 : 6-dibenzophenazine, which may be purified by converting it into the diacetyl compound and again saponifiying; (2) 2-amino-3-methoxynaphthalene in alcoholic solution is oxidized by means of hypochlorite solution to 4 : 8-dimethoxy-1 : 2 : 5 : 6-dibenzophenazine, which is hydrolyzed with hydrobromic acid in glacial acetic acid.  Specifications 318,839, 339,283, [both in Class 2 (iii)], and 379,862 are referred to.  Azo dyes; lakes; azo dyes, forming upon the material; regenerated celluloses, dyeing; printing.--Azo dyestuffs, insoluble in water, are manufactured by coupling a diazotized compound, derived from a monoamine, an aminoazo-compound or a polyamine, with a 4 : 8-dihydroxy-1 : 2 : 5 : 6-dibenzophenazine in substance, on the fibre or on substrata adapted for the production of lakes, only such components being used as do not contain any group lending solubility.  The dyestuffs may be used for the production of fast dyeings and printings or for the production of pigments.  In examples: (3) the dyestuff 1-amino-3-chlorobenzene --> 4 : 8-dihydroxy-1 : 2 : 5 : 6-dibenzophenazine is prepared in substance; when mixed with substrata it yields a dark brown lake; (4) cotton yarn is impregnated with 4 : 8-dihydroxy-1 : 2 : 5 : 6-dibenzophenazine and developed with diazotized 1 - amino - 2 - methoxy - 4 - nitrobenzene, yielding a deep black-brown dyeing; (5) viscose artificial silk is impregnated with the same coupling component and developed with diazotized 1-amino-4-benzoylamino-2 : 5-diethoxybenzene to produce a dark green dyeing.  The dyestuffs can also be produced on animal fibres.  A table describes the dyestuffs obtained from the following additional diazo components: 1 - amino - 2 : 4 - dimethylbenzene, 1 - amino - 2-methyl-5-chlorobenzene, 1-amino-2-phenoxy-5-chlorobenzene, 1-amino-4-benzoylamino-5-methoxy - 2 - chlorobenzene (obtainable by benzoylating 1-amino-2-methoxy-5-chloro-4-nitrobenzene and reducing the product), 1 - amino - 2 - nitrobenzene, 1 - aminoanthraquinone, 4-amino-4<1>-methoxydiphenylamine, 4-amino-3 : 2<1>-dimethylazobenzene, 1-amino-2 : 5-dimethoxy-4<1>-nitroazobenzene.  The Specification as open to inspection under Sect. 91 comprises also the following examples: (1) 2-amino-7-methoxy-3-[(3<1>-carboxybenzene-1<1>-sulphoyl) -hydroxy]-naphthalene (obtainable by condensing 3-hydroxy-7-methoxynaphthalene-2-carboxylic acid amide with 1-carboxybenzene-3-sulphochloride and decomposing the product by Hofmann's reaction) is oxidized with hypochlorite and the product is saponified to produce 4 : 8-dihydroxy-Bz-2<1> : 2<11>-dimethoxy-1 : 2 : 5 : 6-dibenzophenazine; (2) in example (2) above there may be used as starting material 3-p-toluenesulphoylhydroxy - 2 - aminonaphthalene; the hypochlorite may be replaced by another oxidizing agent, e.g. potassium ferrocyanide and caustic soda; (3) 2-amino-3-methoxy-7-bromonaphthalene (obtainable from 3 - methoxy - 7 - bromonaphthalene - 2 - carboxylic acid amide by Hofmann's reaction) is oxidized with copper oxide to 4 : 8 - dimethoxy - Bz - 2<1> : 2<11> - dibromo - 1 : 2 : 5 : 6-dibenzophenazine, which is hydrolyzed by means of hydrobromic acid and glacial acetic acid or aluminium chloride; (4) spun silk is impregnated with 4 : 8 - dihydroxy-1 : 2 : 5 : 6-dibenzophenazine and developed with diazotized 1-amino-2-methoxy-5-chlorobenzene, producing a dark olive dyeing; (5) wool is grounded with the same coupling component and developed with diazotized 1-amino-2-methyl-4-chlorobenzene.  The table describes further dyestuffs, the following additional components being specified: diazo-components-1-amino-2-chloro-5-trifluoromethylbenzene, 3-aminocarbazole, 3-aminobenzophenone, 1-amino-2 : 4 : 5-trichlorobenzene, 1-amino-2-(2<1>-5<1> - dichlorophenoxy) - 5 - chlorobenzene (obtainable by condensing 1 : 4 - dichloro - 2 - nitrobenzene with an alkali salt of 2 : 5 - dichlorophenol and reducing the product), 1 - amino - 2 - methylbenzene - 5 - (carbonyl - 1 - amino - 2 : 5 - dimethoxybenzene) (obtainable by reduction of the corresponding nitro-compound which may be prepared by condensing 1-nitro-2-methylbenzene-5-carboxylic acid with 1-amino-2 : 5-dimethoxybenzene), 1-amino - 4 - benzoylamino - 2 : 5 - dichlorobenzene, 2 - amino - 1 : 6 - dibromonaphthalene, 1-amino-3-methyl-2 : 4-dichlorobenzene, 4 : 4<1>-diamino - 3 : 3<1> - dichlorodiphenyl, 1 - amino - 2 - chlorobenzene, 1 - amino - 2 : 5 - dichlorobenzene, 1-amino-2-methyl-3-chlorobenzene, 1 - amino - 2 - (4<1> - chlorophenoxy) - 5 - chlorobenzene, 1 - amino - 2 - methoxy - 5 - (diethylaminosulphoyl)-benzene, 1-amino-2-phenylsulphoylbenzene, 1-amino-2-methyl-4-nitrobenzene, 1 - amino - 2 - methoxy - 5 - nitrobenzene; coupling component: 4 : 8 - dihydroxy - Bz - 2<1>: 2<11> - dibromo - 1 : 2 : 5 : 6 - dibenzophenazine.  This subject-matter does not appear in the Specification as accepted.