Indoline-2-carboxylic acid, (S)- → (S)-(+)-2-Indolinemethanol

To a solution of (S)-indoline-2-carboxylic acid (9.2 mmol, 1.0 equiv.) in THF (18 ml) was added dropwise BH3-DMS solution (18.4 mmol, 2 equiv.) and the reaction mixture was heated to reflux for 12 h. The mixture was quenched with methanol (7.5 ml) and conc. HCl (2.5 ml) with cooling and was then refluxed for additional 2 h. The solvent was evaporated and the residue was basified with 40% NaOH solution and extracted with dichloromethane. The organic layer was washed with brine, dried over sodium sulfate and the solvent was evaporated under reduced pressure to give the crude product which was purified by silica gel column chromatography. Yield: 87%.

1. temperaturethe reaction mixture was heated
2. temperatureto reflux for 12 h
3. customThe mixture was quenched with methanol (7.5 ml) and conc. HCl (2.5 ml)
4. temperaturewith cooling
5. temperaturewas then refluxed for additional 2 h
6. customThe solvent was evaporated
7. extractionextracted with dichloromethane
8. washThe organic layer was washed with brine
9. dry with materialdried over sodium sulfate
10. customthe solvent was evaporated under reduced pressure

ORD record

ord-5980e20ebdce4253b889a339eb09cf2f

Source dataset

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08541573B2