29-253). This compound had the following binding affinities: IC50 (01)= 16 nM, IC50 (02)= 0.27 nM, IC50 (5-lIT. 1~)= 22 000 nM, IC50 (~-HT~ A)= 270 nM, IC50 (D2)= 4200 nM, IC50 (ad= 220 nM. Spiro-joining of the phenyl and the piperidine rings into a spiro [isobenzofkran- l (3H), 4'-piperidine1 ring system resulted in even more selective compounds. Variations of the l-substituent at the indole and of the chain length of the alkylene spacer group were ...
