Iodoethane → 3-Bromo-4-ethyl-5-fluoropyridine

Temperature

0 °C

n-butyl lithium (92.3 mL, 0.147 mol, 1.6 M) was added to a solution of diisopropyl amine (20.1 mL, 0.147 mol) in tetrahydrofuran (120 mL) at −78° C. and allowed to stir for 30 min at 0° C. The reaction mixture was cooled to −78° C. and a solution of 3-bromo-5-fluoro-pyridine (20.0 g, 0.113 mol) in tetrahydrofuran (20 mL) was added and stirred for 30 min. Ethyl iodide (8.85 mL, 0.124 mol) was added to reaction mixture and allowed to stir at room temperature for 2 h. The reaction mixture was quenched with saturated ammonium chloride (100 mL) solution and extracted with ethyl acetate (3×200 mL). The combined organic extracts were washed with saturated sodium chloride, dried over sodium sulphate and concentrated to provide 3-bromo-5-fluoro-4-ethyl pyridine. 1H NMR (400 MHz, CDCl3) δ 8.49 (s, 1 H), 8.31 (s, 1 H), 2.87-2.82 (m, 2 H), 1.22-1.19 (t, J=4.0 Hz, 3 H). MS (M+1): 205.8.

1. temperatureThe reaction mixture was cooled to −78° C.
2. stirringstirred for 30 min
3. stirringto stir at room temperature for 2 h
4. customThe reaction mixture was quenched with saturated ammonium chloride (100 mL) solution
5. extractionextracted with ethyl acetate (3×200 mL)
6. washThe combined organic extracts were washed with saturated sodium chloride
7. dry with materialdried over sodium sulphate
8. concentrationconcentrated

ORD record

ord-0b6117b6172a4a8ea6f5d95cb42b8dbf

Source dataset

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09351973B2