and alpha 1 adrenoceptors (e.g. 1-[2-[[2-[6-chloro-1-(4-fluorophenyl) -1H-indol-3-yloxy]ethyl]methylamino]-ethyl]-2-imidazolidinone and 1-[3-[[2-[6-chloro-1-(4-fluorophenyl) -1H-indol-3-yl]ethyl]methylamino]propyl]-2-imidazolidinone). The latter derivative has also high selectivity for 5-HT2A receptors versus serotonin 5-HT2C receptors. Replacement of the basic amino group by nitrogen-containing six-membered