Patent GB-420359-A (GB)
Title: Improvements in the manufacture and production of alpha-aminoanthraquinones
IPC: C09B5/24
Filed: 1933-11-20
Abstract: Aminoanthraquinone derivatives.--a  - Nitro - anthraquinones containing in the o-position to the nitro group an anthraquinone-oxazole, -thiazole or -imidazole radicle attached through the carbon atom of the azole ring, are treated with ammonia or agents supplying ammonia whereby the nitro group is replaced by amino.  Suitable agents supplying ammonia are urea, urethane and ammonium carbonate; the use of organic solvents such as nitrobenzene, trichlorbenzene, naphthalene and phenol is advantageous, and in some cases working under pressure while employing catalysts such as metals or metal salts is preferable. The use of high boiling diluents is favoured when the starting material is to be prepared and treated in one operation, and the final product can also be further treated, for example acylated or condensed with halogenated organic compounds, in the same medium. In examples: (1) 1-nitro-2-anthraquinonyl-2<1>.3<1>-anthraquinone oxazole (prepared by ring closure of 1-nitroanthraquinone - 2 - carbonylamino - 2<1>.3<1> - oxyanthra - quinone to the azole compound using concentrated sulphuric acid) is treated with gaseous ammonia in nitrobenzene at 180--190 DEG  C. to give 1 - aminoanthraquinonyl - 2<1>.3<1> - anthra - quinone oxazole (dyes bluish-red shades); phenol may be used as diluent and instead of ammonia urea or urethanes may be employed; 1 - nitro - 2 - anthraquinonyl - 2<1>.3<1> - anthra - quinonethiazole (prepared by condensing 1-nitroanthraquinone-2-carboxylic acid chloride with 2 - mercapto - 3 - aminoanthraquinone at 130--180 DEG C. in nitrobenzene) and the corresponding imidazole (prepared similarly using 2,3 - diaminoanthraquinone); (2) 1 - nitro - 2 - anthraquinonyl - 2<1>.3<1>.6<1> - chloranthraquinone - oxazole (prepared from 1-nitroanthraquinone-2-carboxylic acid chloride and 2-amino-3-oxy-6-chloranthraquinone) is treated as in (1) (dyes yellow - red); (3) 1 - nitro - 2 - anthraquinonyl - 2<1>.1<1>.4<1>-oxyanthraquinone-oxazole (prepared by condensing 1-nitroanthraquinone-2-carboxylic acid chloride with 1-amino-2.4-dioxyanthraquinone followed by ring closure by means of sulphuric acid) is treated as in (1) (dyes bluish-red); (4) 1 - nitro - 2 - anthraquinonyl - 2<1>.1<1> - anthraquinone-oxazole (ring closure of 1-nitroanthraquinone - 2 - carbonylamino - 1<1>.2<1> - oxy - anthraquinone by means of p-toluene sulphonic acid at 180--190 DEG C.) is heated in nitrobenzene with urea (dyes yellow-red); the conversion of 1 - nitro - 2 - anthraquinonyl - 2<1>.1<1> - anthra quinone-thiazole and imidazole (prepared from 1 - nitroanthraquinone - 2 - carboxylic acid chloride and 1,2-diaminoanthraquinone) to the corresponding 1-amino derivatives is effected in similar manner; (5) 1-nitro-2-anthraquinonyl-1<1>(S).2<1>- and 2<1>(S).1<1>-anthraquinone-thiazoles (prepared from 1 - nitroanthraquinone - 2 - carboxylic acid halide and 1-mercapto-2-aminoanthraquinone or 1-amino-2-mercaptoanthraquinone respectively) (dyes bordeaux shades). 2-Amino-3-oxy-6-chloranthraquinone is prepared by first condensing 4-chlorphthalic acid with chlorbenzene, the product nitrated to give 3 - nitro - 4.4<1> - dichlorbenzoylbenzoic acid, the latter treated with dilute soda solution to replace the 4-chloro atom by a 4-oxy group followed by reduction of the nitro group by iron and hydrochloric acid, and then ring-closed by means of concentrated sulphuric acid.