Sodium borohydride → (5-Bromo-2-fluoropyridin-3-yl)methanol

To a suspension of 5-bromo-2-fluoronicotinaldehyde (5.00 g, 24.51 mmol) in ethanol (125 mL) immersed in a room temperature bath to moderate any potential exotherm was added sodium borohydride (0.464 g, 12.26 mmol) in one portion. After 30 minutes at room temperature, LC/MS indicated clean, complete conversion to the product. The reaction was cooled to 0 C and quenched by the cautious addition of saturated ammonium chloride solution (effervescence). The reaction was concentrated and partitioned between water and ether. The etheral was washed with water (2×), then brine, dried over anhydrous magnesium sulfate and concentrated to give a yellow oil which solidified upon standing to give 4.66 g (92% yield) of title compound as yellow crystalline solid. 1H-NMR (CDCl3, 500 MHz) δ: 8.21 (s, 1H), 8.08 (ddd, J=8.3, 1.6, 0.8 Hz, 1H), 4.70-4.88 (m, 2H). Mass spec.: 206.0 (MH)+.

1. customimmersed in a room temperature
2. temperatureThe reaction was cooled to 0 C
3. customquenched by the cautious addition of saturated ammonium chloride solution (effervescence)
4. concentrationThe reaction was concentrated
5. custompartitioned between water and ether
6. washThe etheral was washed with water (2×)
7. dry with materialbrine, dried over anhydrous magnesium sulfate
8. concentrationconcentrated
9. customto give a yellow oil which

ORD record

ord-8e76ef2c09964307a8142c4556dcbe17

Source dataset

uspto-grants-2014_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08691821B2