Abstract: The hom-and heteronuclear correlation spectroscopy techniques were used to make unambiguous assignments of ¹H and ¹³C chemical shifts of chlorpromazine hydrochloride (CPZ· HCl), a well-known psychotropic agent. By comparing of the completely assigned spectra of CPZ· HCl in different solvents (acetone-d₆, chloroform-d and deuterium oxide), it was concluded that the aggregation state of CPZ· HCl differs drastically in different solutions. The data from NMR spectroscopy studies were combined with the results obtained by theoretical calculations to derive the side chain conformations of CPZ· HCl. It was shown that the side chains are in folded forms in acetone and chloroform solutions whereas they inclined to adopt an extended style in aqueous solution.

Key words: 2D NMR, chemical shift, conformation, chlorpromazine hydrochloride, quantum chemical calculation