The Ring Opening of 3,4-Dichloro-1,2,5-thiadiazole with Metal Amides. A New Synthesis of 3,4-Disubstituted-1,2,5-thiadiazoles.

We have developed a new synthesis of 3,4-disubstituted-1,2,5-thiadiazoles. The methodology is based on the ring opening of readily available 3,4-dichloro-1,2,5-thiadiazole with metal amides to afford a stable synthon, which is then transformed into the 3,4-disubstituted-1,2,5-thiadiazole derivatives via two consecutive reactions with O-, S-, N- or Gnucleophiles. (c) 2006 Elsevier Ltd. All rights reserved.