1: 44 percent / NaNO2 / dimethylsulfoxide / 1 h / 135 °C 2: 64 percent / pyridine / 20 h / Ambient temperature 3: 90 percent / conc. HCl / CHCl3; methanol / 64 h / Ambient temperature 4: 89 percent / aluminium isopropoxide / toluene; cyclohexanone / 0.75 h / Heating 5: 80 percent / 5percent KOH / methanol / 4 h / 65 °C View Scheme

potassium acetate in dimethyl sulfoxide T=100°C; 6 h;

sodium nitrite in dimethyl sulfoxide T=135°C; 1 h;

sodium nitrite in dimethyl sulfoxide T=135°C; 1 h;

(i) (heating), (ii) /BRN= 385737/, Py; Multistep reaction;