Thiazolo (2, 3-f) xanthine and thiazolo (2, 3-f) hypoxanthine were synthesized from 8-thioxanthine and 8-thiohypoxanthine via 8-acetonylthio derivatives. Structures of these compounds were determined by desulfurization with Raney Ni and by comparisons of physical data and spectrometrical data with those of thiazolo (3, 2-e) purines.
