Nor verapamil hydrochloride

Nor verapamil hydrochloride is the N-demethylated derivative of verapamil, characterized by a phenethylamine scaffold with a 3,4-dimethoxyphenyl ring and a naphthoxy side chain. The hydrochloride salt forms via protonation of the terminal amine, distinguishing it from the parent drug’s tertiary amine structure. This impurity arises during synthetic pathways due to incomplete methylation, featuring a secondary amine functionality. It serves as a critical HPLC reference standard for quantifying demethylation byproducts in verapamil API batches.