Conformations in unsymmetrically N-n-propyl-N-substituted 2-phenylacetamides

Abstract

As a part of a study on the structural characteristics of some new various N-alkyl-N-substituted 2-phenylacetamides the infrared and 1 H N.M.R. spectra were obtained and interpreted. The synthesis of a various N-n-propyl-N-alkyl 2-phenylacetamides of the general formula PhCH 2 CON(nPr)R, wherein R is ethyl, isopropyl, n-butyl, t-butyl and cyclohexyl, were performed. The corresponding mixed secondary amines of the type HNnPrR were obtained by catalytic hydrogenation of the synthetized propylidenealkylamines. The 1 H N.M.R. spectra of these unsymmetrically N,N-disubstituted amides have been studied and the peaks have been assigned in each cases to two possible conformational isomers, arising from the lack of free rotation about the C(O)N bond. These results are in accordance with our previous investigation of the structure of N-substituted 2-phenylacetamides. © 1992.