hydrogen; palladium on activated charcoal

2,3-dicyano-5,6-dichloro-p-benzoquinone in 1,4-dioxane 1 h;

1: DDQ / dioxane / 1 h 2: 19.88 g / Et3N / CH2Cl2 View Scheme

1: DDQ / dioxane / 1 h 2: 19.88 g / Et3N / CH2Cl2 3: phenyltrimethylammonium tribromide / 1,2-dimethoxy-ethane; CH2Cl2 / 1 h / 40 - 45 °C 4: 18.43 g / Et3N / ethyl acetate / 1.5 h / 20 °C 5: 82 percent / PhPOCl2 / acetonitrile / 2.5 h / Heating 6: 96 percent / aq. NaOH / ethanol / 2 h / 65 - 70 °C View Scheme