(1R,2S)-2-[[(2,4-dimethyl-5-pyrimidinyl)oxy]methyl]-2-(3-fluorophenyl)-N-(5-fluoro-2-pyridinyl)-Cyclopropanecarboxamide is a chiral cyclopropane derivative containing pyrimidine and pyridine rings. It is a key intermediate in the synthesis of Lorlatinib (PF-06463922), a third-generation anaplastic lymphoma kinase (ALK) and ROS1 tyrosine kinase inhibitor. Lorlatinib is an oral medication developed by Pfizer for the treatment of ALK-positive and ROS1-positive non-small cell lung cancer (NSCLC). It is specifically designed to overcome resistance mutations that arise after treatment with earlier-generation ALK inhibitors. This compound represents a crucial synthetic building block in the multi-step production of the final active pharmaceutical ingredient (API). The synthesis and use of this intermediate are critical for ensuring the stereochemical purity and efficacy of Lorlatinib. Its production and handling require specialized facilities adhering to Good Manufacturing Practice (GMP) standards for pharmaceutical intermediates.