Methanol → Methyl 2,3-difluoro-4-methylbenzoate
Reaction equation
[F:1][C:2]1[C:10]([F:11])=[C:9]([CH3:12])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[CH3:13]O.S(=O)(=O)(O)O>>[CH3:13][O:5][C:4](=[O:6])[C:3]1[CH:7]=[CH:8][C:9]([CH3:12])=[C:10]([F:11])[C:2]=1[F:1]Participants
4
Procedure
2,3-Difluoro-4-methyl-benzoic acid (10.0 g, 58.1 mmol) was dissolved in MeOH (200 mL, 6.0 mol) and sulfuric acid (1.00 mL, 19.0 mmol), and was heated at reflux overnight. The mixture was then cooled and concentrated under reduced pressure. The resulting residue was taken up in EtOAc and washed with saturated aqueous NaCl, dried over MgSO4, filtered and concentrated to yield 9.0 g of intermediate (7a) as a white solid. 1H-NMR (CDCl3): 7.61 (1H, t), 7.00 (1H, t), 3.93 (3H, s), 2.35 (3H, s).
Workup
- temperatureat reflux overnight
- temperatureThe mixture was then cooled
- concentrationconcentrated under reduced pressure
- washwashed with saturated aqueous NaCl
- dry with materialdried over MgSO4
- filtrationfiltered
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-e7196562bfc5462eb8a6d714b662ccfb
- Source dataset
- uspto-grants-2011_09
- Patent number
- US08013005B2
Reaction notes
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