Apixaban mono chloro nitro lactum

Apixaban mono chloro nitro lactum is a structurally related impurity derived from the synthetic pathway of apixaban, characterized by a substituted pyridine ring fused to a chlorinated and nitro-substituted lactum moiety. The compound features a 5-chloro-3-nitro oxindole core with a retained pyrimidinone bridge, reflecting partial oxidation and halogenation of the parent apixaban scaffold. This impurity arises via oxidative degradation of the methylene linker under acidic conditions, introducing a nitro group and chlorinating the lactum ring. It serves as a critical HPLC reference standard for quantifying process-related impurities in apixaban active pharmaceutical ingredient batches.