Abiraterone acetate N-Oxide

Abiraterone acetate N-Oxide is a structurally related impurity derived from the CYP17A1 inhibitor Abiraterone, featuring an N-oxidized pyrazole ring and an acetate ester at the 4-position of the androstenedione core. The oxidation state at the pyrazole nitrogen introduces an additional oxygen atom, altering electronic properties and reducing aromaticity compared to the parent compound. This impurity arises during synthetic oxidation steps or oxidative degradation pathways. It serves as a critical HPLC reference standard for quantifying N-oxidized byproducts in Abiraterone acetate drug substance purity profiling.