Ketoprofen impurity J

Ketoprofen impurity J is a synthetic byproduct arising from the alkylation step in Ketoprofen production, characterized by a hydroxyl substitution at the para position of the phenyl ring adjacent to the propionyl chain. The compound retains the core 4-hydroxybenzoic acid scaffold but features an additional hydroxyl group and extended aliphatic chain, leading to altered physicochemical properties. It serves as a critical HPLC reference standard for quantifying process-related impurities in Ketoprofen APIs.