1: 1) diisopropylethylamine, n-BuLi / 1.) THF, hexane, -15 deg C, 1 h, 2.) THF, hexane, RT, 20 h 2: 95 percent / 6M aq. KOH / methanol / 4 h / Heating 3: 76 percent / N-chlorosuccinimide, silver nitrate / H2O; acetonitrile / 0.5 h / Ambient temperature 4: 70 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / toluene / 5 h / 100 °C View Scheme