1H-imidazole in dichloromethane T=0°C; 1 h;

1: 96 percent / pyridine / 2 h / 60 °C 2: 80 percent / trifluoroacetic acid, water / 1 h / Ambient temperature 3: p-toluenesulfonic acid monohydrate / benzene / 1 h / Ambient temperature 4: 5.6 g / 80percent acetic acid / 0.25 h / Ambient temperature 5: 45 percent / mercuric bromide, mercuric cyanide, molecular sieves 4A / acetonitrile / Ambient temperature 6: 95 percent / NaOMe / methanol / 1 h View Scheme

1: p-toluenesulfonic acid / nitromethane; toluene / 1.5 h / 120 - 125 °C 2: 65percent acetic acid / H2O / 1.5 h / 60 °C 3: 70 percent / methanol; triethylamine; H2O / 24 h / 4 °C View Scheme