Pazopanib metabolite M27 HCl

Pazopanib metabolite M27 HCl is a sulfonyl-containing anilino-pyridine derivative featuring a 4-piperidinyl substituent and a terminal hydroxylamine moiety. It arises via oxidative metabolism of the parent drug's piperazine ring, introducing a hydroxylamine functionality at the C-4 position of the piperidine scaffold. The compound retains the core 4-(3-chloro-4-fluoroanilino)-6-methylpyridine-3-sulfonamide pharmacophore but exhibits a truncated aliphatic side chain compared to pazopanib. This structural modification reduces lipophilicity while maintaining hydrogen-bonding capacity. The hydrochloride salt form ensures stability in analytical workflows. This compound serves as an HPLC reference standard for quantifying metabolic degradation pathways in drug stability studies.