1: Lawesson's reagent / tetrahydrofuran / 3 h 2: 2 h / 30 °C 3: triethylamine; nitromethane / N,N-dimethyl-formamide / 12 h / 20 °C / Inert atmosphere 4: ammonium formate / palladium 10 on activated carbon / methanol / 10 h / Reflux View Scheme