Aromatic amides. VII. Steric hindrance to hydrogen bonding in ortho-substituted acetanilides

A series of 2-substituted 3,5-dimethylanilines and their N-acetyl derivatives have been synthesized, and their proton magnetic resonance spectra recorded. Intramolecular hydrogen bonding between the amide N-H and the 2-substituent is disturbed by steric hindrance of the 2-substituent only in the case of the 2-nitro, 2-acetyl, and 2-methoxycarbonyl substituents.