The compounds of this invention possess high affinity for the serotonin 5-HT.sub.1A receptor and as such are useful as antidepressant and anxiolytic agents for the treatment of a variety of central nervous system disorders such as depression, anxiety, eating disorders, sexual disfunction, addiction and related problems. As an example buspirone (U.S. Pat. No. 3,717,634) is known to display potent affinity for the 5-HT.sub.1A serotonin receptor. Buspirone is used extensively for the treatment of anxiety and this anxiolytic activity is believed to be due, at least partially, to its 5-HT.sub.1A receptor affinity [VanderMaelen et al., Eut. J. Pharmacol. 1986, 129 (123-130)].
WO 9,311,122-A and U.S. Pat. No. 4,988,814 exemplify 5-HT1A receptor antagonists as derivatives of piperazine.