DG-041 is a small molecule antagonist of the EP3 receptor for prostaglandin E2 that is in clinical development for treatment of peripheral artery disease (PAD). Originally produced using a six-step synthetic procedure, process optimization led to development of a four-step sequence that is readily scalable. The key step in the optimized sequence contains two sequential Heck reactions, involving an intramolecular Heck cyclization followed by an ...