1: 1.) hexamethyldisilazane, ammonium sulfate, 2.) trimethylsilyl triflate / 1.) reflux, 2.) MeCN, reflux, 5 h 2: Cs2CO3 / acetonitrile / 4 h / Ambient temperature 3: NH3 / methanol / Ambient temperature 4: 4-(dimethylamino)pyridine / acetonitrile / 24 h / Ambient temperature View Scheme

1: NaHCO3 / H2O; diethyl ether / 4 h / Ambient temperature 2: pyridine / 16 h / 8 - 10 °C 3: aq. TFA / 4 h / Ambient temperature 4: pyridine / Ambient temperature 5: 1.) hexamethyldisilazane, ammonium sulfate, 2.) trimethylsilyl triflate / 1.) reflux, 2.) MeCN, reflux, 5 h 6: Cs2CO3 / acetonitrile / 4 h / Ambient temperature 7: NH3 / methanol / Ambient temperature 8: 4-(dimethylamino)pyridine / acetonitrile / 24 h / Ambient temperature View Scheme

1: pyridine / 16 h / 8 - 10 °C 2: aq. TFA / 4 h / Ambient temperature 3: pyridine / Ambient temperature 4: 1.) hexamethyldisilazane, ammonium sulfate, 2.) trimethylsilyl triflate / 1.) reflux, 2.) MeCN, reflux, 5 h 5: Cs2CO3 / acetonitrile / 4 h / Ambient temperature 6: NH3 / methanol / Ambient temperature 7: 4-(dimethylamino)pyridine / acetonitrile / 24 h / Ambient temperature View Scheme

1: Cs2CO3 / acetonitrile / 4 h / Ambient temperature 2: NH3 / methanol / Ambient temperature 3: 4-(dimethylamino)pyridine / acetonitrile / 24 h / Ambient temperature View Scheme

4-(N,N-dimethlyamino)pyridine in acetonitrile 24 h; Ambient temperature; Yield given;