Patent GB-254021-A (GB)
Title: Improved process for the manufacture of benzanthrone derivatives
IPC: C09B3/04
Filed: 1925-03-27
Abstract: 254,021. Ransford, A. J., (Cassella & Co., Ges, L.). March 27, 1925. Azo, hydrazo, and diamino compounds; benzanthrone derivatives. - alpha-Naphthalene-azo-benzene-m-carboxylic acid or a substitution product thereof is reduced to the corresponding hydrazo compound, this is converted in acid solution to a 4 : 4<1>-diaminonaphtlaylphenyl-2<1>-carboxylic acid, and the latter is condensed by means of acid condensing-agents to a diaminobenzanthrone. Other benzanthrone derivatives are obtained by replacing the amino groups of the 4 : 4<1>-diaminonaphthylphenyl-2<1>-carboxylic acid by hydrogen, halogen, hydroxy, methoxy, &c. groups by the Sandmeyer method, and treating the products with acid condensing-agents. The parent azo compounds may be made by boiling with alcohol the diazo compounds of the azo dyes formed by coupling diazobenzene-m-carboxylic acid with a-naphthylamine or its derivatives; the reduction to the hydrazo compounds may be effected by stannous chloride, sulphurous acid, zinc dust, etc.; it may be combined in one operation with the transformation to diamino compound by working in mineral acid solution. The condensation to benzanthrones may be effected by sulphuric acid, chlorsulphonic acid, zinc chloride, &c. ; or the carboxylic acids may be converted into their chlorides and the latter condensed by aluminium chloride. According to examples :- a-naphthalene-azo-benzene-m-carboxylic acid (obtained by boiling with alcohol the diazo compound of maminobenzoic acid # alpha-naphthylamine) is reduced and converted by stannous chloride and hydrochloric acid into 4: 4<1>-diaminonaphthylphenyl-2<1>-carboxylic acid; the tetrazo compound of this bodv yields a violet dye with R-salt; the dihydrochloride of the diamino compound is converted by chlorsulphonic acid into 6 :Bz1-diaminobenzanthrone; a-naphthalene-azo-o-methylbenzene-m-carboxylic acid (obtained from 3- amino-4-methylbenzene-1-carboxylic acid # anaphthylamine) is reduced and converted by sulphurous acid, potassium iodide, and hydrochloric acid to 4 : 4<1>-diaminonaplithyl-5<1>-methylbenzene- 2<1>-carboxylic acid; condensation of this body by means of sulphuric acid or zinc chloride yields 6 : Bz1-diamino-7-methylbenzanthrone; the reduction, transformation, and condensation may be effected in one operation by treating the parent azo body with aluminium bronze and sulphuric acid; 6-methoxy-a-naphthalene-azo-benzene-3<1>-carboxylic acid (obtained from m-aminobenzoic acid # 1-amino-7-methoxynaphthalene is converted to 4 : 4<1>-diamino-7-methoxynaphthylphenyl-2<1>-carboxylic acid, and the latter is condensed to 6 : Bz1-diamino-4-methoxybenzanthrone; the monoazo dye m-aminobenzoic and # 1-amino-7-chlornaphthalene is converted similarly into 6: Bz1-diamino-4-chlorbenzanthrone; 4: 4<1>- diaminonaphthylphenyl-2<1>-carboxylic acid is converted by tetrazotizing and treatment with cuprous chloride into 4 : 4<1>-dichlornaphthylphenyl-2'-carboxylic acid which on condensation yields 6 : Bz1-dichlorbenzanthrone; 4 : 4<1>-diamino - 7 - methoxynaphthylphenyl-2<1>-carboxylic acid is tetrazotized and boiled with alcohol giving 7-methoxynaphthylphenyl-2<1>-carboxylic acid, which is condensed to 4-methoxybenzanthrone; Bz2-methoxybenzanthrone is obtained from 4 : 4<1>-diamino-3-methoxynaphthylphenyl - 2<1>- carboxylic acid similarly. 1-Amino-7-methoxynaphthalene is obtained by methylation of 1-acetylamino-7-oxynaphthalene and saponifying. 1-Amino-7-chlornaphthalene is obtained by reduction of 1-nitro-7-chlornaphthalene