Pilot Plant Scale Synthesis of an Aryl-Indole: Scale Up of a Suzuki Coupling

Abstract

A synthesis of an aryl boronic acid and the subsequent Suzuki coupling to an aryl indole has been developed and successfully scaled up to pilot plant scale. The Suzuki coupling was optimized by design of experiments and run with a catalyst loading of 0.1 mol%. The article describes the strategic approach for the optimization of the reaction and the most critical issues, such as the cryogenic synthesis of the boronic acid, the catalyst optimization, and the palladium removal, are discussed in detail.