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

Reactant 3

HCID 887Methanol

HCID 1118Sulfuric Acid

HCID 27741412,3-Difluoro-4-methylbenzoic acid

Product 1

HCID 55255640Methyl 2,3-difluoro-4-methylbenzoateYield 83.2%

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).