Synthesis of new triazepinethiones

We describe the first synthesis of 7-alkyl-5-aryl-1,2,4-triazepine-3-thiones using hydrazinediium dithiocyanate and α,β-unsaturated ketones as starting materials. Triazepine-3-thiones with this substitution pattern are not accessible by former reported methods. Those compounds may serve as black toning agents for laminated photographs or as starting materials for the synthesis of thiazolo[3,2-b][1,2,4]triazepines, which are supposed to have immunomodulating activities.