Pyrazolotrithiadiazepines and their unexpected rearrangement to 1,2,3-dithiazoles
Abstract
Treatment of 6-bromotrithiadiazepine (1) with Hünig's base in the presence of diaryldiazomethanes (2) gives the trithiadiazepyne cycloadducts (3) which undergo a deep-seated thermal rearrangement to give fused 1,2,3-dithiazoles (4), for which a mechanism is proposed.