Dimethylformamide → 2-Chloro-5-nitro-3-(trifluoromethyl)pyridine

Temperature

80 °C

To a solution of 5-nitro-3-(trifluoromethyl)pyridin-2-ol (1 g, 4.81 mmol) in SOCl2 (10 mL, 137 mmol) was added DMF (0.372 mL, 4.81 mmol). The resulting mixture was stirred at 80° C. for 16 h. After TLC analysis showed the starting material had disappeared, the solvent was removed in vacuo. The residue was dissolved in DCM (60 mL) and washed with aqueous NaHCO3 (20 mL) and brine (20 mL). The organic layer was dried over Na2SO4, filtered and concentrated. The crude product was purified by column chromatography (PE/EA=20/1) to yield a yellow solid of 2-chloro-5-nitro-3-(trifluoromethyl)pyridine (0.8 g, 3.53 mmol, 73.5% yield): 1H NMR (400 MHz, CD3OD) δ 9.42 (d, J=2.8 Hz, 1H), 8.91 (d, J=2.4 Hz, 1H).

1. customthe solvent was removed in vacuo
2. dissolutionThe residue was dissolved in DCM (60 mL)
3. washwashed with aqueous NaHCO3 (20 mL) and brine (20 mL)
4. dry with materialThe organic layer was dried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. customThe crude product was purified by column chromatography (PE/EA=20/1)

ORD record

ord-8ae5d78767694e468ff88d1ea45be6cc

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09382238B2