Abstract: ¹H and ¹³C NMR spectroscopy was used to study the structure and configuration of 3, 5-dimethyladamantanamine hydrochloride salt. Complete NMR assignments were made using DEPT, ¹H-¹H COSY, HSQC and HMBC techniques. The NMR data indicated that the compound has a rigid structure and is comprised of two diastereomeric forms. There are ten peaks in the ¹³C NMR spectrum of the compound within the region δ C 29~54 ppm. Because the compound has two different molecular configurations, there exist three peaks of quaternary carbons in the ¹³C NMR spectrum and two peaks of methyl groups in the ¹H NMR spectrum. The two plane angles between the tertiary proton H-5 and three adjacent CH₂ are near 60°, resulting in very small coupling constants among these protons. Consequently, the resonance of these protons can not be resolved and presents as a singlet in the ¹H spectrum.

Key words: NMR, assignments, 3, 5-dimethyladamantanamine hydrochloride, diastereomeric forms