13C NMR relaxation study and 2D correlation spectroscopic investigation of some quinazoline- and pyrido(4,3-d)pyrimidine-2(1H)-ones and -thiones

Abstract

The conformation in solution and microdynamics of 8-benzylidene-4-phenyl-3,4,5,6,7,8-hexahydroquinazoline-2(1H)-thione (1) have been examined at high-field by two-dimensional NMR correlation spectroscopy and on the basis of T₁ relaxation times. To assist the interpretation theoretical energy calculations (MM2) were invoked. Earlier spectral assignments concerning 1 and related compounds have been corrected.