An Efficient, Scalable Process for Benzphetamine Hydrochloride

Commercial manufacturing of benzphetamine hydrochloride along with its impurity profiling is disclosed. Deoxygenation of pseudoephedrine is reported with ∼100% retention by shielding the amine group as its <i>tert</i>-butyl carbamate, which is very straightforward to eliminate at the end. Four unknown process-related impurities are isolated from the samples of final API and characterized on the basis of their NMR and mass spectral analysis. Structures of the isolated impurities are confirmed by independent syntheses and coinjecting with the isolated one