Ethyl Acetate → 2,6-Difluoro-4-methoxy-benzoic acid tert-butyl ester

HRID 586720Notes

Reaction equation

C([O:5][CH:6]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])N(C)C)(C)(C)C.[F:15][C:16]1[CH:24]=[C:23]([O:25][CH3:26])[CH:22]=[C:21]([F:27])[C:17]=1C(O)=O.C(OCC)(=O)C>C1(C)C=CC=CC=1>[C:11]([O:10][C:6](=[O:5])[C:17]1[C:16]([F:15])=[CH:24][C:23]([O:25][CH3:26])=[CH:22][C:21]=1[F:27])([CH3:12])([CH3:13])[CH3:14]

Participants

Conditions

Temperature: 80 °C

Procedure

N,N-dimethylformamide di-tert-butyl acetal (75 ml, 0.31 mol) in toluene (60 ml) was added dropwise over 1.5 hours to 2,6-difluoro-4-methoxy-benzoic acid (15 g, 80 mmol)(Mol. Cryst. Liq. Cryst. 1989, 172) in toluene (120 ml) at 80° C. under a nitrogen atmosphere. The mixture was stirred at 80° C. for 30 minutes and then cooled to room temperature. Ethyl acetate (100 ml) was added and the organic solution was washed with saturated sodium hydrogen carbonate solution (2×150 ml), brine (150 ml), dried over magnesium sulphate and evaporated under reduced pressure. The residue was purified by chromatography on silica gel using diethyl ether in pentane as eluant (10:90) to give the title compound as an oil (17.91 g).

Workup

temperaturecooled to room temperature
washthe organic solution was washed with saturated sodium hydrogen carbonate solution (2×150 ml), brine (150 ml)
dry with materialdried over magnesium sulphate
customevaporated under reduced pressure
customThe residue was purified by chromatography on silica gel

Sources & evidence

ORD record: ord-06cf3c8c90444c36b3611ee81dae0485
Source dataset: uspto-grants-2005_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06936619B2

Reaction notes

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