1: PPTS / acetone 2: Et3N / toluene / 1.5 h / 10 °C 3: 1.93 kg / NaOH; Bu4NBr / toluene; H2O / 2.5 h / 55 °C 4: aq. HCl / methanol / 3.5 h / Heating 5: 2-picoline / ethyl acetate / 8.5 h / 5 - 10 °C 6: 1.31 kg / Et3N / ethyl acetate / 0.5 h 7: 86 percent / K2CO3 / methanol; H2O / 7 h / 60 °C View Scheme

1: PPTS / acetone 2: Et3N / toluene / 1.5 h / 10 °C 3: 1.93 kg / NaOH; Bu4NBr / toluene; H2O / 2.5 h / 55 °C 4: aq. HCl / methanol / 3.5 h / Heating 5: 2-picoline / ethyl acetate / 8.5 h / 5 - 10 °C 6: 1.31 kg / Et3N / ethyl acetate / 0.5 h 7: 98 percent / KOH / dioxane; H2O / 1 h / 20 °C View Scheme