Syntheses of 6,7-dihydro-4H-indolones 6 and 10 by a selective Birch reduction of the benzene ring of the indole system are described. The antiestrogen zindoxifene and the 2-phenylindole 2 as well as 6 and 10 were tested for their relative binding affinities at the androgen receptor as well as for antiandrogenic and estrogenic properties. Both compounds 6 and 10 showed potent indirect antiandrogenic activity which were similar to those of the 2-phenyl-indoles zindoxifene and 2.