1: 4-bromo-N,N-dibutyl-1-naphthylamine With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 1 h; 2: N,N-dimethyl-formamide in tetrahydrofuran; hexane T=-78 - 20°C; 3: With hydrogenchloride in tetrahydrofuran; hexane 6 h;

1.1: 92 percent / 2,4,4,6-tetrabromo-2,5-cyclohexadien-1-one / CH2Cl2 / 20 °C 2.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -78 °C 2.2: tetrahydrofuran; hexane / -78 - 20 °C 2.3: 55 percent / hydrochloric acid / tetrahydrofuran; hexane / 6 h View Scheme

1.1: 31 percent / potassium carbonate; acetic acid / ethanol / 48 h / 20 °C / Heating 2.1: 92 percent / 2,4,4,6-tetrabromo-2,5-cyclohexadien-1-one / CH2Cl2 / 20 °C 3.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -78 °C 3.2: tetrahydrofuran; hexane / -78 - 20 °C 3.3: 55 percent / hydrochloric acid / tetrahydrofuran; hexane / 6 h View Scheme