1: KOH, hydrazine monohydrate, diethylene glycol / 6 h / 140 °C 2: thionyl chloride / benzene / 0.67 h / Heating 3: AlCl3 / CS2 / 4 h / Heating View Scheme

1: 53 percent / Zn, HgCl2, conc. HCl / H2O; toluene / 24 h / Heating 2: 81 percent / P2O5, H3PO4 / CH2Cl2 / 0.33 h / 70 - 80 °C 3: 69 percent / Zn / tetrahydrofuran / 2 h 4: 62 percent / Pd-black / 2 h / 280 - 300 °C 5: 1) Mg / 1) Et2O, 30 min 2) Et2O, 3h 6: P2O5, H3PO4 / 0.5 h / 60 - 70 °C 7: 86 percent / BBr3 / CH2Cl2 / 1 h / Ambient temperature 8: 40 percent / Potassium nitrosodisulfonate, potassium hydrogen phosphate / acetone; H2O View Scheme

1: 53 percent / Zn, HgCl2, conc. HCl / H2O; toluene / 24 h / Heating 2: 81 percent / P2O5, H3PO4 / CH2Cl2 / 0.33 h / 70 - 80 °C 3: 69 percent / Zn / tetrahydrofuran / 2 h 4: 62 percent / Pd-black / 2 h / 280 - 300 °C 5: 1) Mg / 1) Et2O, 30 min 2) Et2O, 3h 6: P2O5, H3PO4 / 0.5 h / 60 - 70 °C 7: 80 percent / pyridinium chlorochromate / CH2Cl2 / 96 h / Ambient temperature 8: 82 percent / NaBH4 / ethanol / 1 h / Ambient temperature 9: 42 percent / CH3SO2Cl, Et3N / CH2Cl2 / 0 °C 10: 77 percent / NaH, EtSH / dimethylformamide / 3 h / 150 °C 11: 57 percent / potassium nitrosodisulfonate, potassium hydrogen phosphate / H2O; acetone / 4 h View Scheme