Pentane → 5-Chloro-3-(2-methoxypyridin-3-yl)-3-hydroxy-1,3-dihydroindol-2-one

Temperatur

-78 °C

A 1.7 M solution of tert-butyllithium in pentane (28.9 ml, 49.1 mmol) was added to THF (100 ml) at −78° C. 2-Bromomesitylene (3.6 ml, 23.4 mmol) was added dropwise and the mixture stirred at −78° C. for 1 h. 2-Methoxypyridine (1.92 ml, 18 mmol) was added at −78° C. and then the mixture was stirred at 0° C. for 1 h and at ambient temperature for 0.5 h. A suspension of 5-chloroisatin (1.27 g, 9.0 mmol) in THF (50 ml) was added dropwise at −78° C. The reaction mixture was allowed to warm to room temperature and then saturated ammonium chloride solution was added. The mixture was extracted three times with ethyl acetate, and the collected extracts were washed with saturated brine. The organic phase was dried over magnesium sulfate, filtered and concentrated under reduced pressure. Purification by crystallization from dichloromethane yielded 1.1 g of the intermediate.

1. stirringthe mixture was stirred at 0° C. for 1 h and at ambient temperature for 0.5 h
2. additionwas added dropwise at −78° C
3. temperatureto warm to room temperature
4. extractionThe mixture was extracted three times with ethyl acetate
5. washthe collected extracts were washed with saturated brine
6. dry with materialThe organic phase was dried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customPurification
10. customby crystallization from dichloromethane

ORD-Eintrag

ord-2d428e217390467e91d21135773008f7

Quelldatensatz

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08580842B2