(Diethylamino)sulfur trifluoride → 5-Fluoro-4-iodoindolin-2-one

Temperature

-25 °C

A suspension of 1,3-dihydro-1-hydroxy-4-iodo-2H-indol-2-one (2.43 g, 9 mmol) (prepared according to Kende et al., Synth. Commun. 20(14, 2133-2138 (1990)) in dry dichloromethane (500 mL) was cooled to −25° C. under an argon atmosphere with magnetic stirring. A solution of diethylaminosulfur trifluoride (DAST, 1.35 mL) (Aldrich) in dry dichloromethane (40 mL) was added dropwise at such a rate that the reaction temperature did not rise above −25° C. (about 15 min.) After stirring for an additional 30 min. at −25° C., the reaction was quenched by the addition of saturated aqueous sodium bicarbonate solution (180 mL) and allowed to warm to room temperature. The mixture was then filtered through Celite® (Fisher) and the layers separated. The aqueous layer was extracted with dichloromethane (2×300 mL). The dichloromethane layers were washed with saturated aqueous sodium chloride solution (200 mL), combined, dried (magnesium sulfate) and concentrated. The resulting residue was purified by flash chromatography on silics gel using ethyl acetate—dichloromethane (1:7, V/V) as solvent to give 1,3-dihydro-5-fluoro-4-iodo-2H-indol-2-one (Yield 1.08 g, 43%).

1. customdid not rise above −25° C.
2. custom(about 15 min.)
3. customthe reaction was quenched by the addition of saturated aqueous sodium bicarbonate solution (180 mL)
4. temperatureto warm to room temperature
5. filtrationThe mixture was then filtered through Celite® (Fisher)
6. customthe layers separated
7. extractionThe aqueous layer was extracted with dichloromethane (2×300 mL)
8. washThe dichloromethane layers were washed with saturated aqueous sodium chloride solution (200 mL)
9. dry with materialdried (magnesium sulfate)
10. concentrationconcentrated
11. customThe resulting residue was purified by flash chromatography on silics gel

ORD record

ord-22eabc799ee745908f97e450a8040c40

Source dataset

uspto-grants-2001_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06313310B1