1: 19 percent / pyridine, 4-(dimethylamino)pyridine / 16 h / Ambient temperature 2: 13 percent / 1 M NaOH / ethanol / 0.25 h / Ambient temperature 3: 96 percent / acetonitrile / 20 h / Heating 4: NaBH4 / methanol / 1 h / -10 °C 5: HgCl2 / acetonitrile; H2O / 0.25 h 6: NaCNBH3, 1 M HCl, 3-Angstroem molecular sieves / methanol / 112 h / Ambient temperature View Scheme

1: 96 percent / acetonitrile / 20 h / Heating 2: NaBH4 / methanol / 1 h / -10 °C 3: HgCl2 / acetonitrile; H2O / 0.25 h 4: NaCNBH3, 1 M HCl, 3-Angstroem molecular sieves / methanol / 112 h / Ambient temperature View Scheme

1: NaBH4 / ethanol / 1 h / -15 - -10 °C 2: 80 percent / TsOH*H2O / 1.) r.t., 24 h, 2.) 50 deg C, 7 h 3: 100 percent / 1 M aq. NaOH / ethanol / 18 h / Ambient temperature 4: (COCl)2, DMF / toluene / 1 h 5: CBrCl3, 2-mercaptopyridine N-oxide sodium salt, 4-(dimethylamino)pyridine / 1 h / 80 °C / Irradiation 6: aq. AcOH, conc. HCl / 3 h / Ambient temperature 7: 100 percent / KOH / methanol / 3 h / Ambient temperature 8: 84 percent / propan-2-ol / 1.) 70 deg C, 9 h, 2.) r.t., 16 h View Scheme

1: 80 percent / TsOH*H2O / 1.) r.t., 24 h, 2.) 50 deg C, 7 h 2: 100 percent / 1 M aq. NaOH / ethanol / 18 h / Ambient temperature 3: (COCl)2, DMF / toluene / 1 h 4: CBrCl3, 2-mercaptopyridine N-oxide sodium salt, 4-(dimethylamino)pyridine / 1 h / 80 °C / Irradiation 5: aq. AcOH, conc. HCl / 3 h / Ambient temperature 6: 100 percent / KOH / methanol / 3 h / Ambient temperature 7: 84 percent / propan-2-ol / 1.) 70 deg C, 9 h, 2.) r.t., 16 h View Scheme

1: 100 percent / KOH / methanol / 3 h / Ambient temperature 2: 84 percent / propan-2-ol / 1.) 70 deg C, 9 h, 2.) r.t., 16 h View Scheme

1: aq. AcOH, conc. HCl / 3 h / Ambient temperature 2: 100 percent / KOH / methanol / 3 h / Ambient temperature 3: 84 percent / propan-2-ol / 1.) 70 deg C, 9 h, 2.) r.t., 16 h View Scheme

1: CBrCl3, 2-mercaptopyridine N-oxide sodium salt, 4-(dimethylamino)pyridine / 1 h / 80 °C / Irradiation 2: aq. AcOH, conc. HCl / 3 h / Ambient temperature 3: 100 percent / KOH / methanol / 3 h / Ambient temperature 4: 84 percent / propan-2-ol / 1.) 70 deg C, 9 h, 2.) r.t., 16 h View Scheme

1: (COCl)2, DMF / toluene / 1 h 2: CBrCl3, 2-mercaptopyridine N-oxide sodium salt, 4-(dimethylamino)pyridine / 1 h / 80 °C / Irradiation 3: aq. AcOH, conc. HCl / 3 h / Ambient temperature 4: 100 percent / KOH / methanol / 3 h / Ambient temperature 5: 84 percent / propan-2-ol / 1.) 70 deg C, 9 h, 2.) r.t., 16 h View Scheme

1: 100 percent / 1 M aq. NaOH / ethanol / 18 h / Ambient temperature 2: (COCl)2, DMF / toluene / 1 h 3: CBrCl3, 2-mercaptopyridine N-oxide sodium salt, 4-(dimethylamino)pyridine / 1 h / 80 °C / Irradiation 4: aq. AcOH, conc. HCl / 3 h / Ambient temperature 5: 100 percent / KOH / methanol / 3 h / Ambient temperature 6: 84 percent / propan-2-ol / 1.) 70 deg C, 9 h, 2.) r.t., 16 h View Scheme

1: 13 percent / 1 M NaOH / ethanol / 0.25 h / Ambient temperature 2: 96 percent / acetonitrile / 20 h / Heating 3: NaBH4 / methanol / 1 h / -10 °C 4: HgCl2 / acetonitrile; H2O / 0.25 h 5: NaCNBH3, 1 M HCl, 3-Angstroem molecular sieves / methanol / 112 h / Ambient temperature View Scheme