N-Fluorobenzenesulfonimide → Methyl 2-fluoro-2-pyridin-2-ylpropanoate

Temperature

0 °C

To a stirred, cooled (−78° C.) solution of 5.00 mL (10.0 mmol) of a 2.0 M solution of lithium diisopropylamine in tetrahydrofuran under an atmosphere of nitrogen was added a solution of 1.5 g (9.1 mmol) of methyl 2-pyridin-2-yl-propanoate in 4.0 mL of anhydrous THF. The reaction mixture was allowed to stir for 10 min then warmed to 0° C. over 30 min. The mixture was then re-cooled to −78° C. and a solution of 3.70 g (11.8 mmol) of N-fluoro-N-(phenylsulfonyl)benzenesulfonamide in 4.0 mL THF was added. The resulting mixture was allowed to warm to ambient temperature and stir for 2 h. The reaction was quenched with 50 mL of a saturated ammonium chloride solution and then extracted with diethyl ether (3×50 mL). The combined organic layers were dried over magnesium sulfate, filtered and evaporated in vacuo. The crude residue was purified by silica gel chromatography eluting with a 0-40% ethyl acetate in hexanes gradient to afford the title compound as a dark oil (1.3 g, 78%). LC-MS: m/z (E/S) 184 (MH)+.

1. temperatureThe mixture was then re-cooled to −78° C.
2. temperatureto warm to ambient temperature
3. stirringstir for 2 h
4. customThe reaction was quenched with 50 mL of a saturated ammonium chloride solution
5. extractionextracted with diethyl ether (3×50 mL)
6. dry with materialThe combined organic layers were dried over magnesium sulfate
7. filtrationfiltered
8. customevaporated in vacuo
9. customThe crude residue was purified by silica gel chromatography
10. washeluting with a 0-40% ethyl acetate in hexanes gradient

ORD record

ord-32a63da1ed234b4da36c4a1529fc1d5e

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08501786B2