Chemical synthesis. Globally, hemiindigoid derivatives were prepared either by cyclization of a corresponding chalcone, or through condensation of a benzaldehyde with an appropriate benzofuran-2(3H)-one or closely related five-membered cyclic ketone. Regarding 6-dimethylamino-substituted aurones 9 and 13, the prior synthesis of substituted chalcones was achieved starting from commercial phenolic compounds through a final condensation step with 2,4-dimethoxybenzaldehyde (Scheme 1). The other aurone and indanone derivatives were produced from corresponding bicyclic synthons, either purchased from commercial sources or prepared according to previously described methods (Scheme 2).