Fig. 5

Carbon-13 NMR spectrum for the formation of thionicotinamide from 3-cyanopyridine and sulfide with a methanethiol catalyst. Reactions were carried out for 72 h at room temperature. Peaks corresponding to the carbons on the pyridine ring are labeled in both (A and B). Unlabelled peaks in spectrum B correspond to carbons on the 3-cyanopyridine ring. In the presence of the thiol-catalyst, a near complete conversion of 3-cyanopyridine was observed (spectrum A). In the absence of the catalyst, some conversion is still observed, but not to the same extent (spectrum B)