Sodium Thiosulfate → 2-(2,6-Dichloro-4-fluorophenyl)-2H-pyrazolo[4,3-c]pyridine-5-oxide

HRID 626701Notes

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:18]=[C:13]2[CH:14]=[N:15][CH:16]=[CH:17][C:12]2=[N:11]1.C1C=C(Cl)C=C(C(OO)=[O:27])C=1.S([O-])([O-])(=O)=S.[Na+].[Na+]>C(Cl)Cl>[Cl:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[C:4]([Cl:9])[C:3]=1[N:10]1[CH:18]=[C:13]2[CH:14]=[N+:15]([O-:27])[CH:16]=[CH:17][C:12]2=[N:11]1

Participants

Conditions

Temperature: 0 °C

Procedure

To a cooled (0° C.) solution of 2-(2,6-dichloro-4-fluorophenyl)-2H-pyrazolo[4,3-c]pyridine (1.6 g, 5.67 mmol) in DCM (30 mL) under nitrogen, was added mCPBA (1.47 g, 8.51 mmol). The reaction mixture was stirred at 0° C. for 2 hours, warmed to room temperature, and stirred for a further 16 hours. Sodium thiosulfate (sat. aq.) was added and the organic layer was separated, washed with sodium hydrogen carbonate (sat. aq.) and brine, dried over anhydrous magnesium sulfate, and concentrated to dryness under reduced pressure. The residue was purified by silica gel flash chromatography (5-10% methanol in DCM) to afford the title compound as a white solid (1.4 g, 83% yield). 1H NMR (300 MHz, DMSO-d6): δ 8.90 (s, 1H), 8.82 (s, 1H), 7.98-7.87 (m, 3H), 7.83 (d, J=7.5 Hz, 1H).

Workup

temperaturewarmed to room temperature
stirringstirred for a further 16 hours
customthe organic layer was separated
washwashed with sodium hydrogen carbonate (sat. aq.) and brine
dry with materialdried over anhydrous magnesium sulfate
concentrationconcentrated to dryness under reduced pressure
customThe residue was purified by silica gel flash chromatography (5-10% methanol in DCM)

Sources & evidence

ORD record: ord-4532c6d355074943a6863d25634fa6b1
Source dataset: uspto-grants-2016_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09309240B2

Reaction notes

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