Abstract: 4-Amino-5-chloro-2,3-dihydro-N-[1-(3-methoxypropyl)-4-piperidinyl]-7-benzofurancarboxamide was synthesized by amide condensation reaction using 4-amino-5-chloro-2,3-dihydrobenzofuran-7-carboxylic acid and 1-(3-methoxypropyl)-4-piperidinamine as the reactants. The resultant compound, also named prucalopride, is a derivative of dihydrobenzofuran 5-H4 receptor antagonist, and an important drug for treating chronic constipation. The NMR spectrum of prucalopride is crowded and complex due to the fact that there are many carbon atoms in the molecule have similar chemical environment. In this study, ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) and liquid chromatographyhigh resolution mass spectrometry (LC-HRMS) were used to analyze the composition of prucalopride. ¹H NMR, ¹³C NMR, DEPT, ¹H-¹H COSY, ¹H-¹³C HSQC and ¹H-¹³C HMBC spectra of the compound were collected, and its ¹H and ¹³C NMR signals were assigned.

Key words: liquid-state NMR, dihydrobenzofuran-carboxamide derivative, prucalopride, assignment