1: triethylamine / H2O / 5 h / 70 °C 2: 34.7 g / pyridine / 5 h / Ambient temperature 3: 89 percent / acetonitrile / 1.5 h / Ambient temperature 4: dioxane; ethanol / 1.5 h / Ambient temperature 5: methanolic ammonia / 16 h / Ambient temperature View Scheme

1: 34.7 g / pyridine / 5 h / Ambient temperature 2: 89 percent / acetonitrile / 1.5 h / Ambient temperature 3: dioxane; ethanol / 1.5 h / Ambient temperature 4: methanolic ammonia / 16 h / Ambient temperature View Scheme

1: dioxane; ethanol / 1.5 h / Ambient temperature 2: methanolic ammonia / 16 h / Ambient temperature View Scheme

1: diphenyl carbonate, sodium hydrogen carbonate / hexamethylphosphoric acid triamide / 0.33 h / 150 °C 2: triethylamine / H2O / 5 h / 70 °C 3: 34.7 g / pyridine / 5 h / Ambient temperature 4: 89 percent / acetonitrile / 1.5 h / Ambient temperature 5: dioxane; ethanol / 1.5 h / Ambient temperature 6: methanolic ammonia / 16 h / Ambient temperature View Scheme

1: 89 percent / acetonitrile / 1.5 h / Ambient temperature 2: dioxane; ethanol / 1.5 h / Ambient temperature 3: methanolic ammonia / 16 h / Ambient temperature View Scheme

ammonia 16 h; Ambient temperature; Yield given;