Carbon-13 N.M.R. chemical shifts and rotational barriers of ortho-substituted N,N-dimethylbenzamides

Abstract

The barriers to rotation about the carbon-nitrogen bond and the carbon- 13 N.M.R. chemical shifts of a series of 2-substituted N,N- dimethylbenzamides have been measured. The substituent effects have been examined by a multi-substituent parameter method incorporating a steric effect parameter. The barriers to rotation are subject to a large steric effect, whilst the carbon-13 chemical shifts of the carbonyl group and the methyl groups are dominated by the resonance effect.