formic acid; dihydrogen peroxide T=4°C;

1: 69 percent / dimethylformamide / 3 h / 90 °C 2: p-toluenesulfonic acid / acetonitrile; H2O / 5 h / Heating 3: HCO2H; aq. H2O2 / 0 - 5 °C View Scheme

1: p-toluenesulfonic acid / acetonitrile; H2O / 5 h / Heating 2: HCO2H; aq. H2O2 / 0 - 5 °C View Scheme

1.1: H2SO4; KNO3 / 12 h / 0 - 130 °C 1.2: 2.5 g / benzeneselenic anhydride / dioxane / 10 h / Heating 2.1: 90 percent / p-toluenesulfonic acid / toluene / 2 h / Heating 3.1: 69 percent / dimethylformamide / 3 h / 90 °C 4.1: p-toluenesulfonic acid / acetonitrile; H2O / 5 h / Heating 5.1: HCO2H; aq. H2O2 / 0 - 5 °C View Scheme

1: 90 percent / p-toluenesulfonic acid / toluene / 2 h / Heating 2: 69 percent / dimethylformamide / 3 h / 90 °C 3: p-toluenesulfonic acid / acetonitrile; H2O / 5 h / Heating 4: HCO2H; aq. H2O2 / 0 - 5 °C View Scheme

hydrogenchloride in ethanol 3 h; Heating;