abstract |
In the prepn. of 4,4'-diaminostilbene (I) by reacting 2,2'-bis(4-nitro-phenyl)ethane (II) with N2H4 in the presence of a base, (a) a mixt. of one reactant, base and opt. inert diluent is heated to 70-160 deg C; (b) the other reactant is added at this temp.; and (c) reaction is continued at 100-200 deg C. |