4-(N,N-dimethlyamino)pyridine in water; N,N-dimethyl-formamide; acetonitrile

1: 91.2 percent / hydrazine hydrate / acetic acid; pyridine / Ambient temperature 2: 96 percent / sodium nitrite, fluoroacetic acid / 5 h / 0 °C 3: 65.8 percent / 0.05 N methanolic sodium methoxide / 3 h / 50 °C 4: 78 percent / phosphoryl chloride, triethylphosphate / 12 h / 0 °C 5: 1.) N,N'carbonyldiimidazole, 2.) tri-n-butylammonium pyrophosphate / 1.) DMF, RT, 3.5 h, 2.) DMF, RT, 24 h View Scheme

1: stannic chloride / acetonitrile / Ambient temperature 2: 980 mg / sodium methoxide / methanol / 5 h / Ambient temperature 3: 74 percent / tetrachloropyrophosphate / acetonitrile / Ambient temperature 4: 67 percent Spectr. / sodium nitrite, acetic acid / H2O / 4 h / Ambient temperature View Scheme

1: 980 mg / sodium methoxide / methanol / 5 h / Ambient temperature 2: 74 percent / tetrachloropyrophosphate / acetonitrile / Ambient temperature 3: 67 percent Spectr. / sodium nitrite, acetic acid / H2O / 4 h / Ambient temperature View Scheme

1: 4.0 g / H2SO4 / acetic acid; acetic anhydride / 2 h / Ambient temperature 2: stannic chloride / acetonitrile / Ambient temperature 3: 980 mg / sodium methoxide / methanol / 5 h / Ambient temperature 4: 74 percent / tetrachloropyrophosphate / acetonitrile / Ambient temperature 5: 67 percent Spectr. / sodium nitrite, acetic acid / H2O / 4 h / Ambient temperature View Scheme

1: 74 percent / tetrachloropyrophosphate / acetonitrile / Ambient temperature 2: 67 percent Spectr. / sodium nitrite, acetic acid / H2O / 4 h / Ambient temperature View Scheme

1: 67 percent Spectr. / sodium nitrite, acetic acid / H2O / 4 h / Ambient temperature View Scheme

Yield given. Multistep reaction;

1: 78 percent / phosphoryl chloride, triethylphosphate / 12 h / 0 °C 2: 1.) N,N'carbonyldiimidazole, 2.) tri-n-butylammonium pyrophosphate / 1.) DMF, RT, 3.5 h, 2.) DMF, RT, 24 h View Scheme

1: 96 percent / sodium nitrite, fluoroacetic acid / 5 h / 0 °C 2: 65.8 percent / 0.05 N methanolic sodium methoxide / 3 h / 50 °C 3: 78 percent / phosphoryl chloride, triethylphosphate / 12 h / 0 °C 4: 1.) N,N'carbonyldiimidazole, 2.) tri-n-butylammonium pyrophosphate / 1.) DMF, RT, 3.5 h, 2.) DMF, RT, 24 h View Scheme