selenium; hydrazine hydrate; sodium hydroxide in N,N-dimethyl-formamide 4 h; Reflux;

1: dimethylformamide / 5 h / 70 °C / var. halopyridines and polihalopyridines 2: sodium / hexamethylphosphoric acid triamide / 80 °C 3: hexamethylphosphoric acid triamide / 4 h / 120 °C View Scheme

1: sodium / hexamethylphosphoric acid triamide / 80 °C 2: hexamethylphosphoric acid triamide / 4 h / 120 °C View Scheme

in N,N,N',N',N'',N''-hexamethylphosphoric triamide T=120°C; 4 h; Yield given;

in ammonia 3.66667 h; Irradiation;