hydrogenchloride 1 h; Heating;

1: 92 percent / 10percent HCl / 1 h / Heating 2: 78 percent / HBr, Eisessig, Pyridindibromid-hydrobromid / 60 °C 3: 98 percent / 1 h / 50 °C 4: 3percent NaOH / 1.5 h / Ambient temperature View Scheme

1: 92 percent / 10percent HCl / 1 h / Heating 2: 78 percent / HBr, Eisessig, Pyridindibromid-hydrobromid / 60 °C 3: 98 percent / 1 h / 50 °C 4: 3percent NaOH / 1.5 h / Ambient temperature 5: konz. H2SO4 / 4 h / Heating 6: 85 percent / LiAlH4 / diethyl ether / 2 h View Scheme

chromium(VI) oxide; sulfuric acid in acetic acid T=10 - 15°C; 1.5 h;

1: 81 percent / konz. H2SO4/HNO3 2: 80 percent / Fe, Eisessig / 2 h 3: 85 percent / acetic anhydride / 5 h / Heating 4: 98 percent / konz. H2SO4, CrO3 / acetic acid / 1.5 h / 10 - 15 °C View Scheme

1: 85 percent / acetic anhydride / 5 h / Heating 2: 98 percent / konz. H2SO4, CrO3 / acetic acid / 1.5 h / 10 - 15 °C View Scheme

1: 80 percent / Fe, Eisessig / 2 h 2: 85 percent / acetic anhydride / 5 h / Heating 3: 98 percent / konz. H2SO4, CrO3 / acetic acid / 1.5 h / 10 - 15 °C View Scheme

1: 92 percent / 10percent HCl / 1 h / Heating 2: 78 percent / HBr, Eisessig, Pyridindibromid-hydrobromid / 60 °C 3: 98 percent / 1 h / 50 °C 4: 3percent NaOH / 1.5 h / Ambient temperature 5: konz. H2SO4 / 4 h / Heating View Scheme