trifluorormethanesulfonic acid in dichloromethane T=21°C; 0.25 h;

1.1: BuLi / tetrahydrofuran; hexane / 0.5 h / 0 °C 1.2: tetrahydrofuran; hexane; hexamethylphosphoric acid triamide / 15 h / 0 - 25 °C 2.1: 3.03 g / HCl; water / tetrahydrofuran / 1.5 h / 0 - 25 °C 3.1: 97 percent / hydrogen; quinoline / Pd/CaCO3 / methanol / 4 h / 25 °C 4.1: 100 percent / imidazole / dimethylformamide / 18 h / 0 - 25 °C 5.1: 88 percent / dichlorodicyanobenzoquinone / CH2Cl2; H2O / 1 h / 0 - 25 °C View Scheme