Thiazolo [3,2-b]-s-triazole

2-Formamidothiazole and O-mesitylenesulfonylhydroxylamine readily gave 3-umino-2-form-amidothiazolium mesitylenesulfonate that with polyphosphoric acid gave thiazolo [3,2-b]-s-triazole. triazole. In its nmr spectrum, a long-range coupling of 1.4 Hz between H-2 and H-6 is observed.