1: 92 percent / pyridine / 2 h / Ambient temperature 2: (PhO)2POCl, Et3N / acetonitrile / 1.5 h / Ambient temperature 3: 32percent aq. NH3 / dioxane / 0.33 h 4: EtNMe2 / methanol / 24 h / 50 °C View Scheme

ethanol; pyridinium p-toluenesulfonate 24 h; Heating;

1: (PhO)2POCl, Et3N / acetonitrile / 1.5 h / Ambient temperature 2: 32percent aq. NH3 / dioxane / 0.33 h 3: EtNMe2 / methanol / 24 h / 50 °C View Scheme

1: 32percent aq. NH3 / dioxane / 0.33 h 2: EtNMe2 / methanol / 24 h / 50 °C View Scheme

1: 87 percent / p-TsOH / dimethylformamide / 2.5 h / 0 °C 2: 25.1 g / 1 N aq. NaOH / methanol / 1.5 h / Ambient temperature 3: 57 percent / diethylaminosulfur trifluoride (DAST), pyridine / CH2Cl2 / 3 h / Heating 4: 1.) 4-chlorophenyl phosphorodichloridate, 1,2,4-triazole, pyridine, 2.) conc. NH4OH / 1.) RT, 2 d, 2.) dioxane, RT, 1 d 5: 66 percent / pyridinium p-toluenesulfonate (PPTS), C2H5OH / 24 h / Heating View Scheme

1: 25.1 g / 1 N aq. NaOH / methanol / 1.5 h / Ambient temperature 2: 57 percent / diethylaminosulfur trifluoride (DAST), pyridine / CH2Cl2 / 3 h / Heating 3: 1.) 4-chlorophenyl phosphorodichloridate, 1,2,4-triazole, pyridine, 2.) conc. NH4OH / 1.) RT, 2 d, 2.) dioxane, RT, 1 d 4: 66 percent / pyridinium p-toluenesulfonate (PPTS), C2H5OH / 24 h / Heating View Scheme

1: 57 percent / diethylaminosulfur trifluoride (DAST), pyridine / CH2Cl2 / 3 h / Heating 2: 1.) 4-chlorophenyl phosphorodichloridate, 1,2,4-triazole, pyridine, 2.) conc. NH4OH / 1.) RT, 2 d, 2.) dioxane, RT, 1 d 3: 66 percent / pyridinium p-toluenesulfonate (PPTS), C2H5OH / 24 h / Heating View Scheme

1: 82 percent / conc. aq. NH3 / dioxane / 1 h 2: 56 percent / conc. NH3 / 50 °C View Scheme

1: 1.) 4-chlorophenyl phosphorodichloridate, 1,2,4-triazole, pyridine, 2.) conc. NH4OH / 1.) RT, 2 d, 2.) dioxane, RT, 1 d 2: 66 percent / pyridinium p-toluenesulfonate (PPTS), C2H5OH / 24 h / Heating View Scheme

potassium fluoride