[Cl:1][C:2]1[N:7]=[N:6][C:5]([C:8]([NH2:10])=O)=[CH:4][CH:3]=1.N1C=CC=CC=1.C(OC(C(F)(F)F)=O)(C(F)(F)F)=O.O>ClCCl>[Cl:1][C:2]1[N:7]=[N:6][C:5]([C:8]#[N:10])=[CH:4][CH:3]=1A mixture of 6-chloropyridazine-3-carboxamide (described in reference example 3) (15 g, 95.5 mmol) and pyridine (22.6 g, 23.1 ml, 286.6 mmol) were was suspended in dichloromethane and cooled to −30 ° C. under argon. TFAA was added dropwise to the stirred mixture keeping the internal temperature below −20 ° C. The reaction was stirred for 19.5 hours allowing to warm to ambient temperature. The mixture was poured into water(500 ml) and washed with water (4×500 ml) until the aqueous phase was pale yellow. The organic phase was dried over MgSO4, filtered through a pad of silica (50mm diameter, 30mm deep), and concentrated in vacuo. The resulting solid was purified by MPLC (40% dichloromethane/20%ethyl acetate/hexane) to give 3-chloro-6-cyanopyridazine as a colourless solid (5.25 g, 59%).
불러오는 중…