potassium tert-butylate in tetrahydrofuran T=20°C; 2 h;

2,3-dicyano-5,6-dichloro-p-benzoquinone in benzene 4 h; Heating;

1.1: n-butyllithium / diethyl ether; hexane / 2 h / 0 °C 1.2: 82 percent / benzene; hexane / 8 h / Heating 2.1: 81 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / benzene / 4 h / Heating View Scheme