Synthetic routes for products 1‒20. a Thiosemicarbazide, glacial acetic acid, reflux; b dimethyl-N-cyanoimido(dithio)carbonate, diphenoxy-N-cyanoimi -docarbonate, Et3N, DMF, H2O2, galcial acetic acid, reflux; c NaOH, NH2NH2, HCl, DMF, refux; d aldehydes, isothiocyanates, acetic anhydrides, DMF, glacial acetic acid, reflux; e HCl, DMF, reflux; f dimethyl-N-cyanoimido(dithio)carbonate, diphenoxy-N-cyanoimidocarbonate, Et3N, DMF, H2O2, galcial acetic acid, reflux; g dimethyl-N-cyanoimido(dithio)carbonate, diphenoxy-N-cyanoimidocarbonate, Et3N, DMF, reflux