2,4,4,6-tetrabromo-2,5-cyclohexadien-1-one in dichloromethane T=20°C;

1: 31 percent / potassium carbonate; acetic acid / ethanol / 48 h / 20 °C / Heating 2: 92 percent / 2,4,4,6-tetrabromo-2,5-cyclohexadien-1-one / CH2Cl2 / 20 °C View Scheme

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;