Potent and selective corticotropin-releasing factor receptor 1 (CRF1) antagonist (Ki values are 4 and > 10000 nM at CRF1 and CRF2 respectively). Inhibits cAMP accumulation and adrenocorticotropic hormone (ACTH) production in vitro (pIC50 values are 7.1 and 6.9 respectively) and attenuates CRF and ACTH production in vivo. Orally active and brain penetrant with anxiolytic activity.