N-bromobutanimide → 2-Amino-5-bromo-3-fluoropyridine

Temperature

0 °C

To a solution of 3-fluoro-pyridin-2-ylamine (1.0 g, 8.92 mmol) in 300 mL of acetonitrile, NBS (794 mg, 4.46 mmol) was added at 0° C. The reaction mixture was stirred vigorously for 15 minutes (protected from light) at 0° C. and then at room temperature for 1 hour. The additional portion of NBS (794 mg, 4.46 mmol) was added at 0° C. and the solution was stirred at room temperature for 2 hours. The reaction mixture was quenched by addition Na2S2O3 (saturated aqueous solution, 40 mL) and the product was extracted with EtOAc (3×40 mL). The combined organic extracts were washed with brine (2×50 mL), dried over MgSO4 and concentrated in vacuo. The obtained crude yellowish solid was purified by Biotage using 3-20% EtOAc in hexane to afford 5-bromo-3-fluoro-pyridin-2-ylamine (1.2 g). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 7.93 (d, J=1.56 Hz, 1 H) 7.37 (dd, J=9.76, 1.95 Hz, 1 H) 4.63 (br. s., 2 H)

1. waitat room temperature for 1 hour
2. stirringthe solution was stirred at room temperature for 2 hours
3. customThe reaction mixture was quenched by addition Na2S2O3 (saturated aqueous solution, 40 mL)
4. extractionthe product was extracted with EtOAc (3×40 mL)
5. washThe combined organic extracts were washed with brine (2×50 mL)
6. dry with materialdried over MgSO4
7. concentrationconcentrated in vacuo
8. customThe obtained crude yellowish solid
9. customwas purified by Biotage

ORD record

ord-4000ed5cb67c486e96dbe4d857f3a40d

Source dataset

uspto-grants-2010_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07772256B2