The reaction of phenyl isothiocyanate with diazomethane w~ s first described by Pechmann and Nold1 who assigned stru~ ture c (5-anilino-1, 2, 3-thiadiazole) to the product. These authors assumed that the reaction proceeds by one of the two possible reaction mechanisms under formation of four possible products, depending on whether diazomethane adds to the C= N or C= S bond (Scheme 1). Sheenan and Izz02 confirmed ...
