toluene-4-sulfonic acid; potassium iodide; sodium nitrite in water; acetonitrile T=5 - 20°C; 4.16667 h;

1: 2.) 6M aq. HCl / 1.) DMSO, 180 deg C, 5 min, 2.) reflux, 90 min 2: 86 percent / 25percent aq. NH3, H2S / 125 - 135 °C 3: 1.) aq. NaNO2, HCl, 2.) urea, 3.) 10percent aq. KI View Scheme

1: 1.) 48 percent HBr, Br2; 2.) NaNO2 / 1) 30-40 deg C; 2) -5 deg C, H2O; 10-15 Deg C, 90 min.; 3) 40 deg C. 15 min 2: dimethylsulfoxide / 0.08 h / 180 °C 3: 54 percent / HCl / 1.5 h / Heating 4: 70 percent / H2S, 25 percent NH3 5: 1) conc. HCl, NaNO2, urea; 2) KI / 1) H2O, -5 to 0 deg C, 10 min, 0 deg C, 15 min; 2) H2O, 0 deg C, 5 min View Scheme

hydrogenchloride; urea; potassium iodide; sodium nitrite 1) H2O, -5 to 0 deg C, 10 min, 0 deg C, 15 min; 2) H2O, 0 deg C, 5 min; Yield given. Multistep reaction;

1: 86 percent / 25percent aq. NH3, H2S / 125 - 135 °C 2: 1.) aq. NaNO2, HCl, 2.) urea, 3.) 10percent aq. KI View Scheme

potassium permanganate

1: 54 percent / HCl / 1.5 h / Heating 2: 70 percent / H2S, 25 percent NH3 3: 1) conc. HCl, NaNO2, urea; 2) KI / 1) H2O, -5 to 0 deg C, 10 min, 0 deg C, 15 min; 2) H2O, 0 deg C, 5 min View Scheme

1: sulfur trioxide; sulfuric acid; iodine / 210 °C 2: aqueous KMnO4 View Scheme

sulfuric acid