Development and Scale-Up of a Continuous Aerobic Oxidative Chan–Lam Coupling

Despite the benefits of high atom economy and low cost, aerobic oxidations have found limited use in the synthesis of active pharmaceutical ingredients (APIs) because of safety concerns and poor selectivity. In this report, the design, development, and scale-up of a continuous, high pressure aerobic oxidation to produce the penultimate of an API are described. The identification of robust homogeneous conditions for the oxidative C–N coupling of interest and the use of diluted air allowed for the process to be safely and selectively carried out on manufacturing scale as a continuous process using a vertical pipes-in-series reactor to prepare high-quality material.