Optimization of a Urea-containing Series of Nicotinamide Phosphoribosyltransferase (NAMPT) Activators

NAD is a crucial cellular factor that plays multifaceted roles in wide ranging biological processes. Low levels of NAD have been linked to numerous diseases including metabolic disorders, cardiovascular disease, neurodegeneration, and muscle wasting disorders. A novel strategy to boost NAD is to activate nicotinamide phosphoribosyltransferase (NAMPT), the putative rate-limiting step in the NAD salvage pathway. We previously showed that NAMPT activators increase NAD levels in vitro and in vivo. Herein we describe the optimization of our NAMPT activator prototype (SBI-0797812) leading to the identification of 1-(4-((4-chlorophenyl)sulfonyl)phenyl)-3-(oxazol-5-ylmethyl)urea (34) that showed far more potent NAMPT activation and improved oral bioavailability.