Route Development and Bulk Synthesis of CP-865,569

The synthesis of zwitterionic CP-865,569 by three different synthetic routes is described. The first two routes differ in the method of introducing the sulfonic acid at the penultimate step: by sulfite displacement of a benzylic chloride and by oxidation of a benzylic thioacetate. The third route is a convergent route to the drug candidate. The synthesis strategy was primarily driven by the need to introduce the sulfonic acid functionality at the final stage of the synthesis due to the high water solubility and low organic solubility of the desired product.