Methyl iodide → 2,4-Difluoro-3-methylbenzoic acid

To a stirred solution of diisopropylamine (1.7 g, 16.4 mmol) in THF 2.6 M solution of n-BuLi (1.1 g, 16.4 mmol) was added at −30° C. and the mixture was stirred for an hour at the same temperature. To this mixture a solution of 2,4-difluorobenzoic acid (1.0 g, 6.3 mmol) in THF was added slowly at −78° C., followed by methyl iodide (2.2 g, 15.7 mmol) and it was stirred for another 2 h at the same temperature and allowed to attain the room temperature. The reaction mixture was treated with saturated aqueous NH4Cl solution and the aqueous layer extracted with ethylacetate (3×25 mL). The organic phases were combined and dried over anhydrous sodium sulfate. After removal of solvent, the residue was purified over a silica gel flash column using a gradient of ethyl acetate in pet. ether to give product as a white solid. Yield: 0.77 g (70%)

1. stirringwas stirred for another 2 h at the same temperature
2. customthe room temperature
3. extractionthe aqueous layer extracted with ethylacetate (3×25 mL)
4. dry with materialdried over anhydrous sodium sulfate
5. customAfter removal of solvent
6. customthe residue was purified over a silica gel flash column
7. customto give product as a white solid

ORD-Eintrag

ord-7b7e5d33b4f54f66ba710cf08db8ff45

Quelldatensatz

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08658641B2