potassium carbonate in N,N-dimethyl-formamide T=60°C; 7 h;

1: 86 percent / K2CO3 / dimethylformamide / 6 h / 60 °C 2: 82 percent / silica gel-supported nitric acid / CH2Cl2 / 0.25 h 3: 92 percent / hydrazine monohydrate; graphite / ethanol / 12 h / Heating 4: 85 percent / aq. HBF4; t-butyl nitrite / CH2Cl2; tetrahydrofuran / 0.17 h / 10 - 15 °C 5: 88 percent / potassium acetate; 18-crown-6; I2 / CHCl3 / 6 h View Scheme

1: 86 percent / K2CO3 / dimethylformamide / 6 h / 60 °C 2: 82 percent / silica gel-supported nitric acid / CH2Cl2 / 0.25 h 3: 92 percent / hydrazine monohydrate; graphite / ethanol / 12 h / Heating 4: 85 percent / aq. HBF4; t-butyl nitrite / CH2Cl2; tetrahydrofuran / 0.17 h / 10 - 15 °C 5: 88 percent / potassium acetate; 18-crown-6; I2 / CHCl3 / 6 h View Scheme

copper(l) iodide; triethylamine; bis-triphenylphosphine-palladium(II) chloride 4 h; Heating;

sulfuryl dichloride in diethyl ether T=23°C;

1: 90 percent / sulfuryl chloride / diethyl ether / 23 °C 2: 74 percent / NEt3; CuI / bis(triphenylphosphine)palladium(II)dichloride / 5 h / Heating View Scheme

1: 90 percent / sulfuryl chloride / diethyl ether / 23 °C 2: 74 percent / NEt3; CuI / bis(triphenylphosphine)palladium(II)dichloride / 5 h / Heating 3: 85 percent / K2CO3; MeOH / tetrahydrofuran / 3 h / 23 °C View Scheme