phosphoric acid; phosphorus pentoxide in dichloromethane T=70 - 80°C; 0.333333 h;

1: AlCl3 / CH2Cl2 / 6 h / Ambient temperature 2: 5 N NaOH / ethanol / 3 h / Ambient temperature 3: KOH, hydrazine monohydrate, diethylene glycol / 6 h / 140 °C 4: thionyl chloride / benzene / 0.67 h / Heating 5: AlCl3 / CS2 / 4 h / Heating View Scheme

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

aluminium trichloride in carbon disulfide 4 h; Heating;

1: 5 N NaOH / ethanol / 3 h / Ambient temperature 2: KOH, hydrazine monohydrate, diethylene glycol / 6 h / 140 °C 3: thionyl chloride / benzene / 0.67 h / Heating 4: AlCl3 / CS2 / 4 h / Heating View Scheme

1: 87 percent / 20percent aq. NaOH / 2 h / Heating 2: 53 percent / AlCl3 / nitrobenzene / Ambient temperature 3: 53 percent / Zn, HgCl2, conc. HCl / H2O; toluene / 24 h / Heating 4: 81 percent / P2O5, H3PO4 / CH2Cl2 / 0.33 h / 70 - 80 °C View Scheme

1.1: hydroxylamine hydrochloride; aq. NaOH / methanol / 4 h / Heating 2.1: 16.9 g / acetic anhydride; acetic acid; hydrogen chloride / 100 °C 3.1: sodium nitrite; aq. HCl / 0.5 h / 0 °C 3.2: 40 percent / CuCl; aq. HCl / 0 - 75 °C 4.1: 97.53 percent / NiCl2(dppp) / diethyl ether 5.1: 100 percent / AlCl3 / CH2Cl2 / 0.5 h / 0 °C 6.1: boron tribromide / CH2Cl2 / 2 h / 20 °C 7.1: 0.8 g / Dess-Martin periodinane / CH2Cl2 / 20 °C View Scheme

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