sodium tungstate; dihydrogen peroxide in 1,4-dioxane T=60°C; 24 h;

1: 58.8 percent / Et3N / dioxane / 40 h / Ambient temperature 2: 65.5 percent / Na2WO4*2H2O, 30 percent aq. H2O2 / dioxane / 24 h / 60 °C View Scheme