Use of Modeling and Process Analytical Technologies in the Design of a Catalytic Amination Reaction: Understanding Oxygen Sensitivity at the Lab and Manufacturing Scales

A mechanistic approach was undertaken to understand the oxygen sensitivity of a Pd-catalyzed amination reaction used in the synthesis of an active pharmaceutical ingredient. FlowNMR and dissolved oxygen probes were used as process analytical technology alongside kinetic and unit operation models to better characterize the oxidative deactivation pathways of the catalyst. Interplay between ligand excess, oxygen inertion, and additional degassing due to reflux were all found to contribute to reaction rate variability. This mechanistic approach allowed for appreciation and clear communication of the risks, development of protocols to mitigate those risks, and successful scale-up under rapid development timelines.