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 C-nucleophiles.