Patent GB-955743-A (GB)
Title: N-substituted nitrophenylene diamines, their preparation and use in hair-dyeing compoitions
IPC: C09B51/00
Filed: 1961-07-26
Abstract: The invention comprises compounds of formula: <FORM:0955743/C2/1> wherein R is a phenyl radical, an alkyl radical having from 2 to 4 carbon atoms or a hydroxy-alkyl radical having from 1 to 4 carbon atoms in the alkyl group, and also a process for the preparation of 2-nitro -4- aminophenylamine compounds wherein the 1-amino group may be substituted by a hydrocarbon or hydroxy-hydrocarbon radical which is free of olefinic or acetylenic unsaturation, by introducing hydrogen into a mixture at about 0-90 DEG C., of the corresponding 2,4-dinitro-phenylamine dispersed in a polar organic solvent, a platinum or palladium hydrogenation catalyst and sufficient of an aqueous solution of an acid having a dissociation constant greater than 1 x 10-3 to give a pH of less than about 4 and terminating the hydrogenation prior to complete reduction of both nitro groups. The compounds are used in hair dyeing compositions (see Division D1). In an example a platinum on charcoal catalyst, concentrated hydrochloric acid and a solution of 2,4-dinitroaniline in ethanol were charged into an autoclave which was heated to 60-65 DEG C. and hydrogen introduced with constant shaking. After sufficient hydrogen had been introduced to reduce one nitro group, the mixture was cooled to room temperature, filtered, the bulk of alcohol removed by distillation and the residue treated with ammonia to give 4-amino -2- nitroaniline. The preparation of the following compounds is also described: 2-nitro -4- amino -N-methylaniline, 2-nitro -4- amino -N- ethylaniline, 2-nitro -4- amino -N- phenylaniline, 2-nitro -4-amino -N- (2-hydroxyethyl)-aniline, 2-nitro -4-amino -N- (2, 3-dihydroxypropyl)-2, 4-dinitro-aniline, 2-nitro -4- amino -N- (3-hydroxypropyl)-aniline and 2-nitro -4- amino -N- cyclohexyl-aniline.ALSO:The invention comprises dyes of formula <FORM:0955743/C3/1> wherein R is a phenyl radical, an alkyl radical having from 2 to 4 carbon atoms or a hydroxy-alkyl radical having from 1 to 4 carbon atoms in the alkyl group, and also a process for the preparation of 2-nitro-4-aminophenylamine compounds wherein the 1-amino group may be substituted by a hydrocarbon or hydroxy-hydrocarbon radical which is free of olefinic or acetyleric unsaturation, by introducing hydrogen into a mixture at about 0-90 DEG  C., of the corresponding 2,4 - dinitro - phenylamine dispersed in a polar organic solvent, a platinum or palladium hydrogenation catalyst and sufficient of an aqueous solution of an acid having a dissociation constant greater than 1 X 10-3 to give a pH of less than about 4 and terminating the hydrogenation prior to complete reduction of both nitro groups.  The compounds are used in hair dyeing compositions (see Division D1).  In an example a platinum on charcoal catalyst, concentrated hydrochloric acid and a solution of 2,4-dinitroaniline in ethanol were charged into an autoclave which was heated to 60-65 DEG  C. and hydrogen introduced with constant shaking. After sufficient hydrogen had been introduced to reduce one nitro group, the mixture was cooled to room temperature, filtered, the bulk of alcohol removed by distillation and the residue treated with ammonia to give 4-amino-2-nitro-aniline. The preparation of the following compounds is also described:-2-nitro-4-amino-N-methylaniline, 2 - nitro - 4 - amino - N - ethyl-aniline, 2 - nitro - 4 - amino - N - phenylaniline, 2 - nitro - 4 - amino - N - phenylaniline, 2 - nitro - 4 - amino - N - (2-hydroxyethyl) - aniline, 2 - nitro - 4 - amino - N - (2,3 - dihydroxy-propyl) - 2,4 - dinitro - aniline, 2 - nitro - 4 - amino - N - (3 - hydroxypropyl) - aniline and 2-nitro-4-amino-N-cyclohexylaniline.ALSO:The invention comprises a composition for dyeing keratinaceous material comprising an aqueous solution of a tinctorially effective quantity of a p-phenylene-diamine of formula:-  <FORM:0955743/D1-D2/1> wherein R is an alkyl or hydroxyalkyl radical having from 1-4 carbon atoms or a phenyl radical (see Divisions C2 and C4), and a sufficient quantity of an alkalising agent to give a pH of about 7.5-12.  In examples: (1) a mixture of 2-nitro-4-amino-N-(2-hydroxy-ethyl)-aniline, isopropanol, water, monoethanolamine and methyl cellulose was dissolved by warming, cooled, applied to grey hair on the human head, the applied composition left for 25 minutes and then removed by washing, the hair being dyed a bluish-red shade; 1-(2131-dihydroxypropylamino) -or-(31-hydroxypropylamino) -2-nitro-4-aminobenzene gives similar dyeings; (2) an ethanolic solution of 2-nitro-4-amino-N-methyl-or-ethyl-aniline is added to a mixture of water, diethanolamine and agar agar dissolved by warming and applied as in (1) to give dark red and bluish red dyeings; (3) a mixture of a polycarboxylated vinyl resin, sodium dodecylbenzene sulphonate, triethanolamine, water, Dispersed Yellow 5, 2-nitro-4-amino-N-ethylaniline and isopropanol, applied as in (1) gave a blonde shade; (4) a mixture of acrylic acid, water, monoethanolamine, propylene glycol, 2-nitro-4-amino-N-phenylaniline, 2-nitro-4-amino-N-methylaniline, Dispersed Yellow No. 5, Dispersed Violet No. 1 and isopropanol applied as in (1) gave a brown shade.