Abstract: Preparation of N,N'-di(C.sub.1 -C.sub.4 alkyl)perylene-3,4,9,10-tetracarboxylic acid diimides (I) by the reaction of perylene-3,4,9,10-tetracarboxylic acid diimide (II) with a C.sub.1 -C.sub.4 alkyl halide, in which the reaction is carried out in a dipolar-aprotic organic solvent in the presence of an inorganic base.

Abstract: Uniformly dyed water-swellable cellulosic fibers which have been produced by contacting water-swellable cellulosic fibers successively or simultaneously with water, with ethylene glycol, propylene glycol or derivatives of these and with an essentially water-insoluble dye of the formula ##STR1## where Y is unsubstituted or substituted phenyl or naphthyl or an unsubstituted or substituted saturated or unsaturated 5-membered or 6-membered heterocyclic radical, two of the three radicals X are hydroxyl and the remaining radical X is ##STR2## where A is chlorine, bromine, cyano, nitro, an aliphatic, cycloaliphatic, araliphatic or aromatic radical and n is 0, 1, 2 or 3 and where, if n>1, the radicals are identical or different. Deep reddish blue to green dyeings or prints are obtained. The dyeings have very good fastness characteristics.