[Synthesis of 4-aryl-1-lambda-2, 2-lambda- 4-dithia-3,4-diaza-buta-1,2-dienes, a new dithiadiazabutadiene system]

4-Aryl-1 lambda 2, 2 lambda 4-dithia-3,4-diaza-buta-1,2-dienes 1a-12a as representatives of a dithiadiazabutadiene structure in which sulphur occupies a different oxidation number are synthesized by reaction of diazotated acceptor-substituted aryl- and hetarylamines 1-12 with thiosulfates or disodium disulfide in strong acid solution. For some examples a first pharmacological test indicate an immune-stimulating effect. Analytical examination as well as MNDO calculation which give some mechanistical insight, supplements the new synthesis.