Development of a Scalable Synthesis of Oxadiazole Based S1P1 Receptor Agonists

A robust and scalable synthesis was developed for the preparation of oxadiazole based S1P1 inhibitors. A new method for the separation of triphenylphosphine oxide from reaction products and an improved method for the synthesis of oxadiazoles in the presence of DBU were incorporated into the process to achieve its scalability.