Phosphorus oxybromide → 4-Bromo-2-(2,6-dichloro-4-fluorophenyl)-7-fluoro-2H-pyrazolo[4,3-c]pyridine

HRID 626744Notes

Reaction equation

[Cl:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[C:4]([Cl:9])[C:3]=1[N:10]1[CH:20]=[C:13]2[CH:14]=[N+:15]([O-])[CH:16]=[C:17]([F:18])[C:12]2=[N:11]1.P(Br)(Br)([Br:23])=O>ClCCCl.C(Cl)Cl>[Br:23][C:14]1[C:13]2=[CH:20][N:10]([C:3]3[C:2]([Cl:1])=[CH:7][C:6]([F:8])=[CH:5][C:4]=3[Cl:9])[N:11]=[C:12]2[C:17]([F:18])=[CH:16][N:15]=1

Participants

Conditions

Temperature: 0 °C

Procedure

To a cooled (0° C.) suspension of 2-(2,6-dichloro-4-fluorophenyl)-7-fluoro-2H-pyrazolo[4,3-c]pyridine-5-oxide (2.95 g, 9.3 mmol) in DCE (50 mL) was added phosphorus oxybromide (8.0 g, 28 mmol). The reaction mixture was stirred at 0° C. for 1 hour, warmed to room temperature, and stirred for a further 3 hours. The reaction mixture was diluted with DCM and washed with sodium carbonate (sat. aq.). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by silica gel flash chromatography (0-20% ethyl acetate in cyclohexane) to afford the title compound as a white solid (1.0 g, 28% yield). LCMS (Method D): RT=3.82 min, m/z: 380 [M+H+].

Workup

temperatureTo a cooled
temperaturewarmed to room temperature
stirringstirred for a further 3 hours
washwashed with sodium carbonate (sat. aq.)
dry with materialThe organic layer was dried over anhydrous sodium sulfate
concentrationconcentrated under reduced pressure
customThe residue was purified by silica gel flash chromatography (0-20% ethyl acetate in cyclohexane)

Sources & evidence

ORD record: ord-7ac276e6a27d4cddb5ac05b6f17f9cd0
Source dataset: uspto-grants-2016_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09309240B2

Reaction notes

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