As a part of a study on the structural characteristics of some new various N-alkyl-N-substituted 2-phenylacetamides the infrared and H-1 N.M.R. spectra were obtained and interpreted. The synthesis of a various N-n-propyl-N-alkyl 2-phenylacetamides of the general formula PhCH2CON(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 H-1 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.