In this study, N′-substituted 2-aminoacetanilides were synthesised as precursors of pharmacologically relevant 1,4-benzodiazepin-2-ones. The synthetic route comprised two steps: preparation of 2-chloroacetanilides from substituted anilines and subsequent nucleophilic substitution with primary amines. Structural characterisation was performed by NMR spectroscopy (¹H, ¹³C, HSQC, COSY), which revealed a single set of resonances, consistent with the predominance of only one rotamer in solution. DFT calculations enabled geometry optimisation and evaluation of relative rotamer energies. Correlation of theoretical and experimental chemical shifts through the DP4+ statistical method provided reliable support for the structural assignments, reinforcing the experimental findings and ensuring the robustness of the proposed structures.