1: 77 percent / p-toluene sulfonic acid hydrate / acetic acid / 4 h / 45 °C 2: 98 percent / triethylamine, H2 / 10percent palladised charcoal / tetrahydrofuran / 760 Torr / Ambient temperature 3: 1) p-toluene sulfonic acid hydrate; 2) calcium carbonate, phosphoryl chloride / 1) dichloromethane, methanol, 40 min, room temperature; 2) 1.5h, room temperature 4: 85 percent / 1) toluene p-sulfonic acid hydrate; 2) HBr / CH2Cl2; methanol / 16 h 5: 42 percent / trifluoroacetic acid / 0.25 h / Ambient temperature 6: 54 percent / 3percent aqeous sodium hydroxide / pyridine / 2.5 h / Heating View Scheme