1: 96 percent / polyphosphoric acid / 1 h / 90 °C 2: 92 percent / trimethylphenylammonium tribromide / CH2Cl2 / 24 h / Ambient temperature 3: dioxane / 18 h / Ambient temperature 4: NaBH4 / dioxane; methanol; H2O / 12 h / Ambient temperature 5: 78 percent / K2CO3 / dimethylformamide / 48 h / Ambient temperature 6: 91 percent / K2CO3 / dimethylformamide View Scheme