Carbon-13 NMR Studies of Nitrogen Compounds. II.-13C NMR Chemical Shifts of N-Substituted Formamides in Neutral and Acidic Solvents

Abstract
With the purpose to determine the structure of N-formyl pyrazolines1 and their salts, we have undertaken a preliminary study of the effect produced by the replacement of an amino group by a formamido group on the carbon chemical shifts of the substituent R, both in a neutral solvent (hexadeuteriodimethylsuphoxide) and in an acidic solvent (trifluoroacetic acid).