| abstract |
Preparation of 2-substituted 2,4-dihydro-[1,2,4]triazole-3-thiones of the formula (III), comprising the steps i), diazotation of 2-substituted 4-amino-2,4-dihydro-[1,2,4]triazole- 3-thiones by treatment with inorganic nitrites and an acid or in the presence of organic nitrites in an organic solvent or water or mixtures thereof, giving the corresponding 4- diazo-2,4-dihydro-[1,2,4]triazole-3-thiones, and ii), reduction of the diazo intermediate to provide mixtures of compounds of the formula (III) and compounds of the formula (VII), by means of a reducing agent, followed by, iii), treating the reaction mixture with a reducing reagent suitable to cleave disulfide groups. |