sodium hydroxide in ethanol 0.5 h; Heating;

1: 82 percent / Dowex 50W (H+) resin, H2O / methanol / 1.5 h / 70 °C 2: 81 percent / pyridine / 1.25 h / 10 °C 3: 7 h / Heating 4: HCl / ethyl acetate 5: MeOH / 2 h / Heating View Scheme