1: diphenyl ether / 0.2 h / 250 °C 2: 84 percent / trifluoromethanesulfonic acid, trifluoroacetic acid, anisole / 2 h / Ambient temperature 3: 1.) potassium bicarbonate / 1.) DMF, 80 deg, 12 h, 2.) conc. sulfuric acid, 90 deg, 20 min. 4: 73 percent / sodium hydroxide, water / ethanol / 2 h / Heating 5: 41 percent / pyridine / 55 h / Heating View Scheme

1: diphenyl ether / 0.2 h / 250 °C 2: 84 percent / trifluoromethanesulfonic acid, trifluoroacetic acid, anisole / 2 h / Ambient temperature 3: 1.) potassium bicarbonate / 1.) DMF, 80 deg, 12 h, 2.) conc. sulfuric acid, 90 deg, 20 min. 4: 73 percent / sodium hydroxide, water / ethanol / 2 h / Heating 5: 52 percent / pyridine / 75 h / Heating View Scheme

1: diphenyl ether / 0.2 h / 250 °C 2: 84 percent / trifluoromethanesulfonic acid, trifluoroacetic acid, anisole / 2 h / Ambient temperature 3: 1.) sodium / 1.) ethanol, 0 de C,1,5 h, 2.) ethanol, RT, 3,5 h 4: 72 percent / conc. sulfuric acid / 1 h / 0 °C 5: 88 percent / sodium hydroxide, water / ethanol / 2 h / Heating 6: 13 percent / pyridine / 55 h / Heating View Scheme

1: diphenyl ether / 0.2 h / 250 °C 2: 84 percent / trifluoromethanesulfonic acid, trifluoroacetic acid, anisole / 2 h / Ambient temperature 3: 1.) sodium / 1.) ethanol, 0 de C,1,5 h, 2.) ethanol, RT, 3,5 h 4: 72 percent / conc. sulfuric acid / 1 h / 0 °C 5: 88 percent / sodium hydroxide, water / ethanol / 2 h / Heating 6: 34 percent / pyridine / 75 h / Heating View Scheme