The CH2CH2 moiety of medazepam (I) should be treated as an AA'BB' spin system in the NMR spectrum, rather than the ABCD system of G. Romeo, et al. (1981).A torsional angle of ∼55.5° is calculatedThe lack of a dynamic NMR effect of the Me group means that N inversion is still rapid at -130° and/or that only 1 N invertomer predominates.