1: 64 percent / 20percent aqueous oxalic acid / hot 2: 51 percent / oxygen / palladium chloride, copper(II) chloride / dimethylformamide; H2O / 70 °C / 1) 150 min, 2) 1 h View Scheme

1: 64 percent / 20percent aqueous oxalic acid / hot 2: 51 percent / oxygen / palladium chloride, copper(II) chloride / dimethylformamide; H2O / 70 °C / 1) 150 min, 2) 1 h 3: 87 percent / sodium hydroxide / methanol / 3 h / 15 °C View Scheme

1: 64 percent / 20percent aqueous oxalic acid / hot 2: 4 percent / oxygen / palladium chloride, copper(II) chloride / dimethylformamide; H2O / 70 °C / 1) 150 min, 2) 1 h View Scheme