Conformation and dynamics of ranitidine in solution as detected by 1H and 13C NMR spectroscopy

Conformational and dynamic features of ranitidine were delineated by 1H and 13C NMR 1D and 2D spectroscopy. Spin–lattice relaxation rates and homo- and hetero-nuclear NOEs were measured. An extended conformation was shown to predominate in solution, with restricted segmental motion. The main reorientational motion and some of the internal motions were characterized in terms of stochastic internal motion around a molecular axis that reorients isotropically. Selective irradiation methods were used to obtain relevant conformational parameters.