Antisolvent/cooling and quench crystallization methodologies stand as predominant techniques in the crystallization domain, widely employed for the purification of starting materials, intermediates, and active pharmaceutical ingredients (APIs), as well as for identifying suitable polymorphs for drug products in the pharmaceutical industry. Quench crystallization, compared to antisolvent/cooling crystallization, exhibits the capability to generate crystals in the same reactor by introducing reactive agents to the completed reaction, driven by the release of precipitating product and changes in solubility. Sotorasib (AMG510), a KRAS inhibitor, was developed by Amgen. During the production of the drug substance of Sotorasib, an intermediate B, derived from A via Boc deprotection, was isolated and purified via quench crystallization. The study detailed in the article (OPRD 2023, 27, 1499) demonstrated the feasibility of this crystallization method by developing a workflow specialized for reactive crystallization. Process analytical technologies (PATs) were employed to study the phase dynamics and crystallization mechanism in-depth, guiding the successful deployment of the strategy.