Patent GB-469016-A (GB)
Title: Manufacture of (n-dihydro)-azines of the anthraquinone series
IPC: A61C15/02
Filed: 1936-01-13
Abstract: Anthraquinone - N - dihydroazines are made by treating with an acid or alkaline agent the condensation product from an o-halogenanthraquinone sulphonic acid or a derivative thereof and an amine of the formula NH2.R.NHR1, wherein R means an aromatic radical in which the NH2 and NHR1 groups are in o-position and R, means an aliphatic or aromatic radicle. Ring-closure takes place with elimination of sulphurous acid.  R may contain substituents, aliphatic radicals, or nuclei joined to other aliphatic, aromatic, or heterocyclic radicals by CH2--, CO--, NH--or like bridges.  R1 may, when it is an aromatic radical, be connected with R through an oxygen bridge as well as through the NH group, and may contain substituents such as alkyl, aryl, aralkyl, acyl, aroyl, alkylsulphone, or arylsulphone.  Acid or alkaline agents specified are caustic soda or potash, sodium or potassium carbonate and hydrochloric, sulphuric, or phosphoric acids.  The products dye wool blue to greenish-blue shades.  In examples, 1 - brom (or iodo) - anthraquinone-2 - sulphonic acid is condensed with (1) o-aminodiphenylamine, (2) 3-amino-4-methylamino - benzene - sulphonic acid, (3) 2-amino-2<1>-carboxy-diphenylamino, (4) 3-amino-4-b -hydroxyethylamino - benzene - sulphonic acid, (5) 2-aminodiphenylamine-4-sulphonic acid, (7) 2 - amino - 4<1> - chlordiphenylamine - 4 - sulphonic acid, (8) 2-amino-4<1>-dimethylaminodiphenylamine - 4 - sulphonic acid, (9) 2-amino-4-sulphodiphenylamine - 4<1> - carboxylic acid, (10) 2 - amino - 4 - sulphodiphenylamine-2<1> - carboxylic, (11) 2 - amino - 4<1> - acetylaminodiphenylamine - 4 - sulphonic acid, (13) 2 - amino - 4 - sulphodiphenylamine - 4<1>-hydroxy - 3<1> - carboxylic, (14) 2 - amino - 4-sulphodiphenylamine - 5<1> - sulpho - 2<1> - hydroxy - 3<1> - carboxylic acid, (15) 2 - amino-2<1> - nitrodiphenylamine - 4<1> - sulphonic acid (16) 2 - methylamino - 3 - amino - 5 - sulpho, benzoic acid, (17) 1-cyclohexylamino-2-aminobenzene-4-sulphonic acid, (18) 3-amino-4-phenylamino - benzophenone - 2<1> - carboxylic acid, (19) monoacetyl - o - phenylene diamine, and (23) 5 - aminophenoxazine - 3 - carboxylic acid, the condensation being followed by ring closure to the dihydrozine.  The nitro-group in the product of (15) may be reduced by sodium sulphide.  In other examples, sodium 1.5 - di - iodo (or dibrom-)-anthraquinone-2 : 6-disulphonate is condensed with (20) 2-aminodiphenylamine-4-sulphonic acid, (21) 2-amino-4 - sulpho - 4<1> - hydroxy - diphenylamine-3<1>-carboxylic acid, and (22) 2-amino-4-sulpho-4<1> - acetaminodiphenylamine; (6) 1-bromanthraquinone - 2 - sulphomethyltauride is condensed with 2-aminodiphenylamine-4-sulphonic acid; (12) 1-iodo-4-bromanthraquinone-2-sulphonic acid is condensed with 2-amino-4 - sulphodiphenylamine - 4<1> - hydroxy - 3<1>-carboxylic acid, the product being heated with aqueous ammonia to exchange the bromine atom for NH2 or reacted with amines.  3 - Amino - 4 - methylamino - benzenesulphonic acid is obtained by condensing 4-chloro-3-nitrobenzene-1-sulphonic acid with methylamine and reducing the nitro group.  3 - Amino - 4 - b  - hydroxyethylaminobenzene sulphonic acid is obtained by condensing aminoethanol with 4-chloro-4-nitrobenzene sulphonic acid and reduction of the nitro group.  Various aminodiphenylamine sulphonic acids are made from the corresponding chlor- and aminobenzene derivatives in the usual manner, any nitro groups present being subsequently reduced to amino groups.  2 - Methylamino - 3 - amino - 5 - sulphobenzoic acid is obtained by reaction of 4-chloro-4-nitro - 5 - carboxybenzene - 1 - sulphonic acid with methylamine, followed by reduction of the nitro group.  1 - Cyclohexylamino - 2 - aminobenzene - 4-sulphonic acid is obtained by condensing 4-chloro-3-nitrobenzene-1-sulphonic acid with cyclohexylamine and reducing the nitro group.  3 - Amino - 4 - phenylamino - benzophenone-2<1>-carboxylic acid is obtained by condensing 4 - chloro - 3 - nitrobenzo - phenone - 2<1>-carboxylic acid with aniline and reduction of the nitro group.  5 - Aminophenoxazine - 3 - carboxylic acid is obtained by condensation of 4-chloro-3.5-dinitrobenzoic acid with o-aminophenol, splitting off of nitrous acid and reduction of the NO2 group.