Studies on organophosphorus compounds XXVI. Synthesis and ¹³C NMR spectra of N,N‐dialkyl thioamides

Abstract

Abstract By a new thiation reagent, 1, 4, 11 the dimer of p ‐methoxyphenylthionophosphine sulfide, 3, a series of thioamides have been prepared in almost quantitative yields from the corresponding amides, Carbon‐13 NMR spectra of tertiary thioamides of formic, acetic, trifluoroacetic, propionic and butyric acids have been completely assigned with the aid of extensive double resonance and shift reagent experiments and the data obtained have been compared with those of the analogous amides. 8 Also a linear relation between the 13 C chemical shifts of CS of the thioamides and CO of the corresponding amides has been found by a least square linear regression analysis: δ(CS) = 1.60° (CO)−72.3.