1: 15 percent / NaH / hexamethylphosphoric acid triamide / 4 h / 110 °C 2: 2N aq. KOH / dioxane / 20 h / 20 °C 3: 1.) 1,1'-carbonyldiimidazole / 1.) DMF, from 40 deg C to 45 deg C, 10 min, 2.) DMF, 20 deg C, 30 min View Scheme

1: 15 percent / NaH / hexamethylphosphoric acid triamide / 4 h / 110 °C 2: 2N aq. KOH / dioxane / 20 h / 20 °C 3: 1.) 1,1'-carbonyldiimidazole / 1.) DMF, from 40 deg C to 45 deg C, 10 min, 2.) DMF, 20 deg C, 30 min View Scheme

1: 2N aq. KOH / dioxane / 20 h / 20 °C 2: 1.) 1,1'-carbonyldiimidazole / 1.) DMF, from 40 deg C to 45 deg C, 10 min, 2.) DMF, 20 deg C, 30 min View Scheme

1,1'-carbonyldiimidazole 1.) DMF, from 40 deg C to 45 deg C, 10 min, 2.) DMF, 20 deg C, 30 min; Multistep reaction;