Ethanol → 2-(2,4-Difluorophenoxy)pyrido[3,2-d]pyridazin-5(6H)-one
Reaction equation
[F:1][C:2]1[CH:18]=[C:17]([F:19])[CH:16]=[CH:15][C:3]=1[O:4][C:5]1[CH:12]=[CH:11][C:8]([C:9]#N)=[C:7]([CH:13]=O)[N:6]=1.[NH2:20][NH2:21].CC[OH:24]>>[F:1][C:2]1[CH:18]=[C:17]([F:19])[CH:16]=[CH:15][C:3]=1[O:4][C:5]1[CH:12]=[CH:11][C:8]2[C:9](=[O:24])[NH:20][N:21]=[CH:13][C:7]=2[N:6]=1Participants
4
Procedure
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
Workup
- customThe EtOH was removed under reduced pressure
- additionThe remaining residue was treated with AcOH (10 mL)
- temperaturethe reaction mixture was heated at 90° C. for 15 min
- customresulting in the precipitation of a yellow solid
- additionThe suspension was treated with ice
- stirringstirred for 5 min
- filtrationThe solid was filtered
- washrinsed with 5 mL of water
- 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
Sources & evidence
- ORD record
- ord-e0760bdfb5ea4303a256d303171b866d
- Source dataset
- uspto-grants-2014_07
- Patent number
- US08772481B2
Reaction notes
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