Sodium Hydroxide → 1H-Indazol-3-ylmethanol

Commercially available indazol-3-carboxylic acid (500 mg, 3.08 mmol) was dissolved in tetrahydrofuran (THF) (10 mL) and sodium bis(2-methoxyethoxy)aluminum hydride (70% toluene solution, 1.78 g, 6.17 mmol) was added thereto under ice-cooling, under argon atmosphere, followed by stirring for 2 hours under heating and reflux. Sodium bis(2-methoxyethoxy)aluminum hydride (70% toluene solution, 2.67 g, 9.25 mmol) was further added to the mixture under ice-cooling and the mixture was stirred for 2 hours under heating and reflux. Under ice-cooling, 2 mol/L sodium hydroxide solution (10 mL) was added, and the mixture was stirred for 15 minutes at a room temperature. The organic layer was separated and the aqueous layer was extracted with THF (5 mL, 3 times). The organic layer was collected, and washed with saturated brine. The aqueous layer was extracted with ethyl acetate (5 mL, 2 times), all organic layers were collected and dried over anhydrous magnesium sulfate followed by concentration under reduced pressure. The residue was recrystallized by toluene/THF (10:1) (5 mL) and the precipitated crystal was collected by filtration, followed by washing with torulene/THF (10:1) (1 mL). The obtained crystal was dried under reduced pressure to thereby yield Compound (I) (349 mg, 2.36 mmol, 77%).

1. temperatureunder ice-cooling, under argon atmosphere
2. temperatureunder heating
3. temperaturereflux
4. temperaturecooling
5. stirringthe mixture was stirred for 2 hours
6. temperatureunder heating
7. temperaturereflux
8. temperatureUnder ice-cooling
9. stirringthe mixture was stirred for 15 minutes at a room temperature
10. customThe organic layer was separated
11. extractionthe aqueous layer was extracted with THF (5 mL, 3 times)
12. customThe organic layer was collected
13. washwashed with saturated brine
14. extractionThe aqueous layer was extracted with ethyl acetate (5 mL, 2 times)
15. customall organic layers were collected
16. dry with materialdried over anhydrous magnesium sulfate
17. concentrationfollowed by concentration under reduced pressure
18. customThe residue was recrystallized by toluene/THF (10:1) (5 mL)
19. filtrationthe precipitated crystal was collected by filtration
20. washby washing with torulene/THF (10:1) (1 mL)

ORD record

ord-751bf28a5bf947789fbd974e5208db55

Source dataset

uspto-grants-2010_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07759491B2