Polynitrated diaryl compounds of the formula given in the description are reduced with 1-2 mols of sulphides, or compounds which donate sulphide ions, per mol of nitro group in the presence of 0.5-10 mols of ammonia per mol of starting compound at 30.degree.-110.degree. C. to give nitroamino-diaryl compounds, for example 4,4'-dinitro-dibenzyl-2,2'-disulphonic acid is reduced to 4-nitro-4'-amino-stilbene-2,2'-disulphonic acid.
根据描述给出的公式,多硝基二芳基化合物在每摩尔硝基基团存在0.5-10摩尔
氨的情况下,使用1-2摩尔
硫化物或捐赠
硫离子的化合物还原,反应温度为30度至110度,以得到硝基
氨基二芳基化合物,例如4,4'-二硝基二苯基-2,2'-二
磺酸被还原为4-硝基-4'-
氨基-亚苯基-2,2'-二
磺酸。