1: HBr / CH2Cl2 / 3 h / -20 °C 2: Bu3SnH, azobis(isobutyronitrile) / toluene / Heating 3: 30 percent / CF3SO3SiMe3 / acetonitrile / 5 h / Ambient temperature 4: 85 percent / NH3 / methanol / 18 h / Ambient temperature View Scheme

Multi-step reaction with 3 steps 1: 39.8 percent / dibenzo-18-crown-6 / dimethylsulfoxide / 4 h / 205 - 210 °C2: 98 percent / H2 / 10percent Pd/C / ethanol / 72 h / Ambient temperature3: 81 percent / pyridine / 12 h / Ambient temperature