1: 2) H2O / 1) dioxane, 120 deg C, 5 h, 2) dioxane, reflux, 1 h 2: 55.2 percent / Ac2O, azeotropic HBr in H2O / 4 h / 140 °C View Scheme

1: 64.2 percent / p-TsOH / benzene / Heating; azeotropic dist. 2: 2) H2O / 1) dioxane, 120 deg C, 5 h, 2) dioxane, reflux, 1 h 3: 55.2 percent / Ac2O, azeotropic HBr in H2O / 4 h / 140 °C View Scheme

1: 2.)water / 1.) dioxane, 5 h, reflux, 2.) 45 min, reflux 2: 55 percent / azeotropic hydrobromic acid / acetic anhydride View Scheme

1: 80 percent / NaOH / H2O / 6 h / Heating 2: 88 percent / NH3 / tetrahydrofuran / -78 deg C to room t. 3: 45percent NaOH / benzene; H2O / Ambient temperature 4: benzene / 4 h / Heating View Scheme

Heating;