Hydrochloric Acid → 1,4-Dihydro-4-oxo-1-[3-(trifluoromethyl)phenyl]-3-pyridazinecarboxylic acid
Reaction equation
[O:1]=[C:2]1[CH:7]=[CH:6][N:5]([C:8]2[CH:13]=[CH:12][CH:11]=[C:10]([C:14]([F:17])([F:16])[F:15])[CH:9]=2)[N:4]=[C:3]1[C:18]([O:20]C)=[O:19].[OH-].[Na+].Cl>CO>[O:1]=[C:2]1[CH:7]=[CH:6][N:5]([C:8]2[CH:13]=[CH:12][CH:11]=[C:10]([C:14]([F:17])([F:16])[F:15])[CH:9]=2)[N:4]=[C:3]1[C:18]([OH:20])=[O:19]Participants
5
Procedure
To a suspension of methyl 4-oxo-1-[3-(trifluoromethyl)phenyl]-1,4-dihydropyridazine-3-carboxylate (10.0 g, 33.5 mmol) in MeOH (150 mL) was added 1 M NaOH aqueous solution (50 mL) at 0° C. The mixture was stirred at room temperature for 30 min. To the suspension was added 1 M HCl aqueous solution (50 mL) at 0° C. The mixture was concentrated in vacuo. The precipitates were collected by filtration, washed with water and dried in vacuo at 50° C. to yield the title compound (9.25 g, 97% yield) as a pale yellow solid: 1H NMR (DMSO-d6, 300 MHz): δ ppm 7.02 (1H, d, J=7.7 Hz), 7.81-7.96 (2H, m), 8.06-8.21 (2H, m), 9.16 (1H, d, J=7.7 Hz).
Workup
- concentrationThe mixture was concentrated in vacuo
- filtrationThe precipitates were collected by filtration
- washwashed with water
- customdried in vacuo at 50° C.
Sources & evidence
- ORD record
- ord-0e8cac1dd2314af1b33c5deba9413bbe
- Source dataset
- uspto-grants-2013_05
- Patent number
- US08435995B2
Reaction notes
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