Experimental and Theoretical NMR Study of (s)-Doxazosin

Abstract

(1)H, (13)C, DEPT, (1)H-(1)H COSY NMR and HSQC NMR spectra of (s)-doxazosin were reported. All the (1)H and (13)C NMR data were assigned. There were 9 quaternary C atoms in the (s)-doxazosin molecule, and most of them were difficult to be identified only by experimental data. (13)C NMR chemical shifts of (s)-doxazosin were calculated by means of the Hartree-Fock (HF) and Becke-3-Lee-Yang-Parr (B3LYP) density functional theory methods with 6-21G basis sets respectively. Comparison between the experimental and the theoretical results indicated that both methods had good correlation. This was helpful to assign the NMR shifts of quaternary C atoms.