(3aS)-1-methyl-3,3-diphenyl-hexahydropyrrolo(1,2-c)(1,3,2)oxazaborole → (S)-2-bromo-1-pyridin-3-yl-ethanol

(S)-2-Methyl-CBS-oxazaborolidine (1M in toluene, 189 μL, 0.18 mmol) and borane-methyldisulfide complex (2M in toluene, 100 μL) in THF (11 mL) was allowed to stir at room temperature for 10 min. Then, the rest of BH3—S(CH3)2 (2M in toluene, 1.33 mL, 2.85 mmol) was added to the reaction solution followed by a suspension of 3-(bromoacetyl)pyridine hydrochloride (0.5 g, 1.78 mmol) in THF (11 mL). The heterogeneous reaction mixture was stirred at room temperature for 16 h. The reaction mixture was then cooled to 0° C. and quenched with MeOH (1.5 mL). After 5 min of stirring, the solvent was removed and the resulting residue was diluted with CH2Cl2. The solution was treated with saturated NaHCO3 and the organic phase was separated. The aqueous phase was re-extracted with CH2Cl2. The combined organic phase was dried over Na2SO4 and concentrated. The resulting residue was purified by silica gel prep TLC using 95:5 CH2Cl2:MeOH as an eluent to afford 0.24 g of (S)-2-bromo-1-pyridin-3-yl-ethanol as a colorless oil (66%).

1. stirringThe heterogeneous reaction mixture was stirred at room temperature for 16 h
2. temperatureThe reaction mixture was then cooled to 0° C.
3. customquenched with MeOH (1.5 mL)
4. stirringAfter 5 min of stirring
5. customthe solvent was removed
6. additionthe resulting residue was diluted with CH2Cl2
7. additionThe solution was treated with saturated NaHCO3
8. customthe organic phase was separated
9. extractionThe aqueous phase was re-extracted with CH2Cl2
10. dry with materialThe combined organic phase was dried over Na2SO4
11. concentrationconcentrated
12. customThe resulting residue was purified by silica gel prep TLC

ORD record

ord-54ebadcc923c4a23874584b3d1a8029a

Source dataset

uspto-grants-2009_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07601714B2