o-Azidohetarenecarbaldehydes react with bis(trimethylsilyl)sulfide and hydrochloric acid to give fused isothiazoles in yields strongly dependent upon the nature of the heteroaromatic ring through intramolecular cyclization reaction of presumable intermediate o-azidocarbothialdehydes.
Treatment of aromatic and heteroaromatic o-azidoaldehydes with bis(trimethyl-silyl)sulfide and a suitable catalyst affords an easy access to the corresponding o-azidothioaldehydes as their Diels-Alder cycloadducts with dienes.
Capperucci, Antonella; Degl'innocenti, Alessandro; Funicello, Maria, Phosphorus, Sulfur and Silicon and the Related Elements, 1994, vol. 96, # 1-4, p. 479 - 480