Dimethylformamide → (5-Bromopyridin-2-yl)methanol

Temperature

-78 °C

Dissolve 2,5-dibromopyridine (10 g, 42 mmol) in toluene (500 mL) and cool to −78° C. Add 2.5M n-butyllithium in hexane (20.3 mL, 50.6 mmol) and stir the mixture for 7 h at the same temperature. Add DMF (4.2 mL, 54.87 mmol) and stir for 1 h. Warm the solution to 0° C. and add sodium borohydride (3.2 g, 84.42 mmol). Stir the mixture at ambient temperature for 3 h. Dilute with EtOAc and saturated aqueous NH4Cl. Separate the layers and extract the aqueous layer three times with EtOAc. Dry over anhydrous Na2SO4, filter and concentrate in vacuo. Recrystallization from hexane/EtOAc (9:1) gives the desired intermediate as a white solid (5.3 g, 66%).

1. temperatureWarm the solution to 0° C.
2. stirringStir the mixture at ambient temperature for 3 h
3. customSeparate the layers
4. extractionextract the aqueous layer three times with EtOAc
5. dry with materialDry over anhydrous Na2SO4
6. filtrationfilter
7. concentrationconcentrate in vacuo
8. customRecrystallization from hexane/EtOAc (9:1)

ORD record

ord-f2f88fca1fb2402793b339b828839a83

Source dataset

uspto-grants-2011_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08022062B2