Abstract: This invention encompasses compounds of the formula wherein Ar represents a mono- , di- or trisubstituted aryl group where at least one position on Ar ortho to the point of attachment to the pyrazole ring is substituted; and R1 represents lower alkyl; R2 is hydrogen or lower alkyl; and R3 and R4 independently represent organic and inorganic substituents, which compounds are highly selective partial agonists or antagonists or human CRF1 receptors and are useful in the diagnosis and treatment of treating stress related disorders such as post traumatic stress disorder (PTSD) as well as depression, headache and anxiety.