1: 81 percent / triphenylphosphane; bromine; imidazole / CH2Cl2 / 2 h / 0 °C 2: 80 percent / ethanol; H2O / 6 h / Heating 3: aq. HCl; H2 / platinum oxide / propan-2-ol / 16 h / 2585.74 Torr View Scheme

1: 40 percent / Ph3P; Br2 2: 82 percent / TFA View Scheme

1.1: 73 percent / TEA / CH2Cl2 / 3.5 h / 0 - 20 °C 2.1: 47 percent / acetone / Heating 3.1: BCl3 / CH2Cl2 / 20 °C 3.2: 82 percent / MeOH View Scheme

1H-imidazole; bromine; triphenylphosphine in dichloromethane T=0°C; 2 h;