1: 94 percent / 25percent aqueous KOH / 2 h / Heating 2: 70 percent / dimethylformamide / 1 h / Heating View Scheme

1: 94 percent / 25percent aqueous KOH / 2 h / Heating 2: 70 percent / dimethylformamide / 1 h / Heating 3: 83 percent / oxalylchloride / hexane / 1 h / Heating 4: 100 percent / diethyl ether / 0.5 h / 0 °C View Scheme

1: 94 percent / 25percent aqueous KOH / 2 h / Heating 2: 70 percent / dimethylformamide / 1 h / Heating 3: 83 percent / oxalylchloride / hexane / 1 h / Heating 4: 96 percent / diethyl ether / 0.5 h / 0 °C 5: 94 percent / 10 wt percent Cu(acac)2 / benzene / Heating 6: 91 percent / 0.08 h / 400 °C View Scheme