Synthesis of 3-amino-4-hydroxylaminothiazolidine-2-thiones and 2,3-dimethyl-4α,5-dihydro-7-thioxothiazolo[3,4-b]-1,2,4-triazines

The reaction of dimeric nitroso chlorides of olefins with potassium dithiocarbazate was used to synthesize 3-amino-4-hydroxylaminothiazolidine-2-thiones, which undergo rearrangement to 2-mercapto-1,3,4-thiadiazines on heating and react with butane-2,3-dione to give 2,3-dimethyl-4α,5-dihydro-7-thioxothiazolo[3,4-b]-1,2,4-triazine 4-oxides. The latter are reduced by sodium borohydride to the corresponding 3,4,4α,5-tetrahydro-7-thioxo derivatives. The IR spectra of KBr pellets of the compounds were recorded with a Perkin-Elmer spectrometer. The UV spectra of solutions in ethanol were obtained with a Specord UV spectrophotometer. The PMR spectra of solutions of the compounds in d6-DMSO were obtained with a Varian FT-80A spectrometer with tetramethylsilane (TMS) as the internal standard