Water → 3,3-Dimethyl-5-(methylsulfonyl)indolin-2-one

Temperature

-75 °C

5-Bromo-3,3-dimethyl-1,3-dihydro-2H-indol-2-one (2 g, 8.3 mmol) was dissolved in freshly distilled tetrahydrofuran with tetramethylethylenediamine (2 g, 17.2 mmol) and was cooled to -75° C. under nitrogen. n-Butyllithium in hexane (2.5M, 8 ml, 20 mmol) was added and the mixture was stirred at -75° C. for 40 minutes. Dimethyl disulfide (1 g, 10.6 mmol) was added and the mixture was allowed to warm to room temperature. Water (5 ml) was added and the mixture was concentrated under reduced pressure, the resulting oil was taken up in dichloromethane, washed with dilute hydrochloric acid, dried (MgSO4), filtered and concentrated to dry under reduced pressure. The resulting oil was taken up in acetic acid, sodium perborate (7 g, 45 mmol) was added and the mixture was stirred at 50° C. overnight. The mixture was poured into water and extracted with ethyl acetate. The combined organic phases were washed with 2N sodium hydroxide solution, dried (MgSO4), filtered and concentrated under reduced pressure. Column chromatography on silica gel (eluent ethyl acetate/hexane) gave 3,3-dimethyl-5-methanesulfonyl-1,3-dihydro-2H-indol-2-one as a pale yellow solid.

1. temperatureto warm to room temperature
2. concentrationthe mixture was concentrated under reduced pressure
3. washwashed with dilute hydrochloric acid
4. dry with materialdried (MgSO4)
5. filtrationfiltered
6. concentrationconcentrated
7. customto dry under reduced pressure
8. stirringthe mixture was stirred at 50° C. overnight
9. extractionextracted with ethyl acetate
10. washThe combined organic phases were washed with 2N sodium hydroxide solution
11. dry with materialdried (MgSO4)
12. filtrationfiltered
13. concentrationconcentrated under reduced pressure

ORD record

ord-cc8a18b5e13d4dafb2bbab0281685605

Source dataset

uspto-grants-1998_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05773448