Carbon-13 nuclear magnetic resonance studies of piperidine and piperazine compounds. Part I. Empirical substituent parameters for C-methyl and N-methyl groups
Abstract
The carbon-13 chemical shifts of a number of piperidine and piperazine compounds have been measured. Substituent parameters have been derived, for methyl groups bonded to carbon and nitrogen, from the symmetrically substituted compounds and used to predict results for unsymmetrical compounds in good agreement with experimental values.