triethylamine; trifluoroacetic anhydride T=0 - 20°C; 3 h; Inert atmosphere;

1: K2cr2O7; H2SO4; water / und Essigsaeure 2: SnCl2 View Scheme

sulfuric acid unter Kuehlung;

potassium dichromate; sulfuric acid; water und Essigsaeure;

1.1: 72 percent / MsCl; Et3N / tetrahydrofuran / 1 h / 20 °C 2.1: (1R,2R)-1-[[3',5'-(CF3)2-C6H3]-NH-C(S)-NH]-2-NMe2-cC6H10 / toluene / 24 h / 20 °C 3.1: 94 percent / NaBH4 / NiCl2 / methanol / 7.5 h / 20 °C 4.1: NaOH / ethanol / 45 h / 20 °C 4.2: toluene / 6.5 h / Heating 4.3: aq. HCl / 24 h / Heating View Scheme