Pyridoxine impurity A-HCl

Pyridoxine impurity A-HCl is a chlorinated pyridine derivative featuring a 2-chloro substituent, 3,4-dihydroxy, and 5-hydroxymethyl functional groups. This impurity arises via oxidative chlorination during Pyridoxine synthesis, differing from the parent compound by the replacement of a hydroxyl group with chlorine. Its structural similarity to Pyridoxine enables competitive chromatographic interactions, while the hydrochloride salt form ensures stability. It functions as an HPLC reference standard for quantifying synthetic byproducts in Pyridoxine formulations.