| abstract |
Benzoxazolyl-stilbenes of the formula <IMAGE> in which R is a 6-membered heterocyclic radical which has 2 nitrogen atoms in the o-position, m-position or p-position relative to one another, and one of Z and Zo is hydrogen and the other is hydrogen or chlorine, and the benzene nucleus A can carry conventional non-chromophoric substituents, processes for their preparation and their use for the fluorescent brightening of organic material. |