Reactivity Studies of Thiophosgene and its Halo Versions towards Diazo Derivatives

The reactions of thiophosgene with diazo derivatives gives dichloro-alkene derivatives and cyclized, 1,2,3-thiadiazoles respectively. The product formation is mainly depending on substitutions on diazo substrates. When its halo versions, CSBr2 and in combination with bromide ion, CSBr2 less reactive than bromide ion with disubstituted diazo, give gem-dihalo derivatives whereas more reactive with mono substituted diazo to gives 1,2,3-thiadiazoles. In case CSI2 irrespective of substitution on diazo, iodide ion is more reactive then CSI2 was observed.