1: 54 percent / pyridine / dioxane / 1.) 2 h, room temperature, 2.) 1 h, 70 - 80 deg C. 2: 74 percent / potassium t-butylate / dioxane / 1.) 30 min, room temperature, 2.) 2 h, reflux 3: 91 percent / conc. H2SO4 / H2O; acetic acid / 1.5 h / Heating View Scheme

in water

1: 54 percent / pyridine / dioxane / 1.) 2 h, room temperature, 2.) 1 h, 70 - 80 deg C. 2: 74 percent / potassium t-butylate / dioxane / 1.) 30 min, room temperature, 2.) 2 h, reflux View Scheme