Water → 6-Chloropyridazine-3-carbonitrile

Temperature

-30 °C

A 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 (50 mm diameter, 30 mm 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%).

1. customthe internal temperature below -20° C
2. temperatureto warm to ambient temperature
3. washwashed with water (4×500 ml) until the aqueous phase
4. dry with materialThe organic phase was dried over MgSO4
5. filtrationfiltered through a pad of silica (50 mm diameter, 30 mm deep)
6. concentrationconcentrated in vacuo
7. customThe resulting solid was purified by MPLC (40% dichloromethane/20%ethyl acetate/hexane)

ORD record

ord-0041bc3013ac4e0fa969f2666b497cf7

Source dataset

uspto-grants-1999_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05994353