The invention relates to a process for the preparation of nitroanilines, which consists in reacting an amine RNH.sub.2, or ammonia, with 3,4-methylenedioxynitriobenzene to give the products of the formula: ##STR1## in which R denotes hydrogen, alkyl, monohydroxyalkyl or polyhydroxyalkyl, alkoxyalkyl or aminoalkyl of the formula: ##STR2## in which R.sub.1 and R.sub.2, which are identical or different, denote hydrogen, alkyl or monohydroxyalkyl or polyhydroxyalkyl and n denotes an integer from 2 to 4, or of the formula: ##STR3## in which A denotes OCH.sub.2 or ##STR4## and R.sub.1 denotes --CH.sub.2 CH.sub.2 OH or ##STR5## or their salts. The invention also relates to the dyeing compositions for keratin fibres, and in particular for hair, which contain a dyestuff of the above formula (I) in which R denotes alkyl, polyhydroxyalkyl, alkoxyalkyl or aminoalkyl of the abovementioned formula, and to the dyestuffs of the formula (I) in which R denotes alkoxyalkyl or aminoalkyl of the above formula, and of the formula (IIB), which are novel.
该发明涉及一种制备
硝基苯胺的方法,其包括将胺RNH.sub.2或
氨与3,4-亚甲基二氧基
亚硝基苯反应,得到以下化合物的产物:##STR1## 其中R代表氢、烷基、单羟基烷基或多羟基烷基、烷氧基烷基或
氨基烷基的化合物:##STR2## 其中R.sub.1和R.sub.2,相同或不同,代表氢、烷基或单羟基烷基或多羟基烷基,n代表从2到4的整数,或以下式的化合物:##STR3## 其中A代表OCH.sub.2或##STR4## 而R.sub.1代表--CH.sub.2 CH.sub.2 OH或##STR5## 或它们的盐。该发明还涉及角蛋白纤维的
染料组合物,特别是用于头发的
染料组合物,其中含有上述式(I)中R代表烷基、多羟基烷基、烷氧基烷基或上述式的
氨基烷基的
染料,以及式(I)中R代表上述式的烷氧基烷基或
氨基烷基,以及式(IIB)的
染料,这些都是新颖的。