(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) (see below) in dry dichloromethane (500 mL) was cooled to −25° C. under an argon atmosphere with magnetic stirring. A solution of (diethylamino)sulfur 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 Scientific) 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. Residue was purified by flash chromatography on sitics get 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 Scientific)
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. customResidue was purified by flash chromatography on sitics
12. customget

ORD record

ord-8ab785272bef4fd1acd4276488f943e8

Source dataset

uspto-grants-2001_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06303793B1