Pyrazole → 1-(5-Bromo-3-fluoro-2-nitro-phenyl)-1H-pyrazole

Temperature

0 °C

To a suspension of sodium hydride (44 mg, 1.1 mmol, 60% oil dispersion) in THF (4 mL), stirred at 0° C., was added a solution of pyrazole (72 mg, 1.05 mmol) in THF (1 mL). The resulting mixture was stirred at 0° C. for 5 minutes and a solution of 5-bromo-1,3-difluoro-2-nitro-benzene (238 mg, 1 mmol) in THF (1 mL) was added. The mixture was stirred at room temperature for 1 hour, quenched by addition of water (1 mL), then partitioned between water (20 mL) and ethyl acetate (50 mL). The organic layer was washed with brine, dried (MgSO4), and concentrated in vacuo. The residue was purified by column chromatography over silica gel eluted with ethyl acetate:hexanes (1:6), to afford 240 mg (86%) of the title compound. 1H NMR (CDCl3) δ 6.55 (t, 1H), 7.45 (d, 1H), 7.60 (s, 1H), 7.80 (m, 2H). MS M+1 287, M+1+2 289.

1. stirringThe resulting mixture was stirred at 0° C. for 5 minutes
2. stirringThe mixture was stirred at room temperature for 1 hour
3. customquenched by addition of water (1 mL)
4. custompartitioned between water (20 mL) and ethyl acetate (50 mL)
5. washThe organic layer was washed with brine
6. dry with materialdried (MgSO4)
7. concentrationconcentrated in vacuo
8. customThe residue was purified by column chromatography over silica gel
9. washeluted with ethyl acetate:hexanes (1:6)

ORD record

ord-c723dde19f414430bdb3d217bd5fc7c8

Source dataset

uspto-grants-2009_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07582641B2