反应条件
1: 62 percent / pyridine / dioxane / 1.) 2 h, room temperature, 2.) 1 h, 70 - 80 deg C. 2: 85 percent / potassium carbonate / dimethylformamide / 2 h / 140 - 150 °C 3: 92 percent / conc. H2SO4 / H2O; acetic acid / 1.5 h / Heating 4: 79 percent / pyridine / 8 h / Heating 5: 98 percent / conc. HCl / H2O / Heating View Scheme
