Development of an Efficient Synthesis of Two CRF Antagonists for the Treatment of Neurological Disorders

BMS-764459 (1) and BMS-763534 (2) are CRF1 antagonists for the treatment of neurological disorders such as depression and anxiety. An efficient synthesis of 1 and 2 is described, which features an efficient palladium-catalyzed cyanation of a 5-chloropyrazinone where zinc acetate suppresses dehalogenation. This synthesis was applied to the preparation of > 5 kg of 1 and 2 for clinical studies.