tris(4-methoxyphenyl)-phosphine; silver benzoate; palladium (II) bromide in 1,4-dioxane T=125°C; 16 h; Inert atmosphere;

O-(2,4,6-trimethylbenzenesulfonyl)hydroxylamine in chloroform T=25°C; 1 h;

potassium carbonate in N,N-dimethyl-formamide Ambient temperature;

sulfur in neat (no solvent) T=260°C; 1 h;

1: H2, 1percent aq. NaOH / Pd/C / H2O / Ambient temperature 2: 1.) NaNO2, HCl 3: 1.) SnCl2, conc. HCl; 2.) 2.5percent HCl / 1.) 15 h; 2.) reflux, 5 min 4: 15.5 g / p.toluenesulfonic acid / benzene / 6 h / Heating 5: Na / various solvent(s) / 1 h / Heating 6: 83 percent / NaOH / ethanol / 2.5 h / Heating 7: sulfur / neat (no solvent) / 1 h / 260 °C View Scheme

hydrogen iodide 3 h; Heating;

1: 15.5 g / p.toluenesulfonic acid / benzene / 6 h / Heating 2: Na / various solvent(s) / 1 h / Heating 3: 83 percent / NaOH / ethanol / 2.5 h / Heating 4: sulfur / neat (no solvent) / 1 h / 260 °C View Scheme

1: 15.5 g / p.toluenesulfonic acid / benzene / 6 h / Heating 2: Na / various solvent(s) / 1 h / Heating 3: 83 percent / NaOH / ethanol / 2.5 h / Heating 4: sulfur / neat (no solvent) / 1 h / 260 °C View Scheme

1: 1.) NaNO2, HCl 2: 1.) SnCl2, conc. HCl; 2.) 2.5percent HCl / 1.) 15 h; 2.) reflux, 5 min 3: 15.5 g / p.toluenesulfonic acid / benzene / 6 h / Heating 4: Na / various solvent(s) / 1 h / Heating 5: 83 percent / NaOH / ethanol / 2.5 h / Heating 6: sulfur / neat (no solvent) / 1 h / 260 °C View Scheme

1: Na / various solvent(s) / 1 h / Heating 2: 83 percent / NaOH / ethanol / 2.5 h / Heating 3: sulfur / neat (no solvent) / 1 h / 260 °C View Scheme