反应详情

To a solution of 6-(2,4-difluorophenoxy)-2-formylnicotinonitrile (2.24 g, 8.6 mmol) in 15 mL of EtOH at 0° C. was added anhydrous hydrazine (1.4 mL, 43 mmol). The resulting mixture was stirred at RT for 5 min. The EtOH was removed under reduced pressure. The remaining residue was treated with AcOH (10 mL) and the reaction mixture was heated at 90° C. for 15 min, resulting in the precipitation of a yellow solid. The suspension was treated with ice and stirred for 5 min. The solid was filtered, rinsed with 5 mL of water followed by 2×2 mL of ether, and dried in a vacuum oven at 45° C. for 18 h to 2-(2,4-difluorophenoxy)pyrido[3,2-d]pyridazin-5(6H)-one as a yellow fluffy solid. MS (ESI, pos.ion) m/z: M+1=276.0

1. customThe EtOH was removed under reduced pressure
2. additionThe remaining residue was treated with AcOH (10 mL)
3. temperaturethe reaction mixture was heated at 90° C. for 15 min
4. customresulting in the precipitation of a yellow solid
5. additionThe suspension was treated with ice
6. stirringstirred for 5 min
7. filtrationThe solid was filtered
8. washrinsed with 5 mL of water
9. dry with materialdried in a vacuum oven at 45° C. for 18 h to 2-(2,4-difluorophenoxy)pyrido[3,2-d]pyridazin-5(6H)-one as a yellow fluffy solid