Process optimization details are disclosed following the completion of process design for a second-generation manufacturing route of adagrasib. Key objectives for development included control of difficult-to-purge impurities in the key starting materials (KSMs), enhanced scalability of the KSM, improved pyrimidone formation of the core, increased robustness of oxidation, enhanced stability of the step 3 intermediate, removal of the halogenated solvent in the fourth step, and implementation of single crystallization of the final API. These improvements led to more efficient production of adagrasib and a further reduction in the cost of goods by approximately 50%.