A series of N3-pyridylpyrazinones was investigated as corticotropin-releasing factor-1 receptor antagonists. It was observed that the binding affinity of analogues containing a pyridyl group was influenced not only by the substitution pattern on the pyridyl group, but also by the pKa of the pyridyl nitrogen. Analogues containing a novel 6-(difluoromethoxy)-2, 5-dimethylpyridin-3-amine group were among the most potent N3-pyridylpyrazinones ...