Ibuprofen EP Impurity F

Ibuprofen EP Impurity F is a positional isomer of ibuprofen, characterized by a hydroxyl substitution at the para-position of the aromatic ring relative to the isobutyl group. This structural deviation introduces a vicinal diol motif adjacent to the phenylpropanoid backbone, altering steric and electronic properties compared to the parent API. The compound arises as a synthetic byproduct during Friedel-Crafts alkylation steps, featuring an identical carbon skeleton but with reversed ortho/para hydroxyl placement. Functions as a critical HPLC reference standard for quantifying process-related impurities in ibuprofen formulations.