Apremilast racemic amino sulfone

Apremilast racemic amino sulfone is a chiral API impurity derived from the parent drug, featuring a pyrrolidinone core substituted with a sulfonyl group (SO2) at the 4-position and a racemic amino functionality at the 3-position. The compound exhibits a sulfonyl moiety replacing the sulfonamide in Apremilast, with the amino group existing as a 1:1 mixture of enantiomers due to the chiral center adjacent to the sulfone. This impurity arises during oxidative stress conditions and serves as a critical HPLC reference standard for quantifying process-related stereoisomeric deviations in Apremilast synthesis.