Potassium Carbonate → 1-(4-methoxybenzyl)-4-nitro-1H-indazole

HRID 2237409Notes

Reaction equation

[N+:1]([C:4]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:5]=1[CH:6]=[N:7][NH:8]2)([O-:3])=[O:2].C(=O)([O-])[O-].[K+].[K+].[CH3:19][O:20][C:21]1[CH:28]=[CH:27][C:24]([CH2:25]Cl)=[CH:23][CH:22]=1>CN(C=O)C.O>[CH3:19][O:20][C:21]1[CH:28]=[CH:27][C:24]([CH2:25][N:8]2[C:9]3[C:5](=[C:4]([N+:1]([O-:3])=[O:2])[CH:12]=[CH:11][CH:10]=3)[CH:6]=[N:7]2)=[CH:23][CH:22]=1

Participants

Conditions

Temperature: 110 °C

Procedure

To a suspension of 4-nitro-1H-indazole (10 g, 61.30 mmol) and potassium carbonate (9.32 g, 67.43 mmol) in DMF (100 mL) at 25° C. was added 4-methoxybenzyl chloride (9.14 mL, 67.43 mmol). The resulting mixture was stirred at 110° C. for 2 hours. The reaction mixture was cooled and diluted with water. The aqueous layer was extracted with DCM (2×100 mL). The organic layer was dried over MgSO4, filtered and concentrated. The residue was purified by flash chromatography on silica gel eluting with 0 to 2% ethyl acetate in dichloromethane. The solvent was evaporated to dryness to afford 1-(4-methoxybenzyl)-4-nitro-1H-indazole (9.00 g, 51.8%) as a orange solid. NMR Spectrum: (DMSOd6) 3.70 (s, 3H), 5.73 (s, 2H), 6.87 (d, 2H), 7.25 (d, 2H), 7.65 (dd, 1H), 8.17 (d, 1H), 8.34 (d, 1H), 8.54 (s, 1H).

Workup

temperatureThe reaction mixture was cooled
extractionThe aqueous layer was extracted with DCM (2×100 mL)
dry with materialThe organic layer was dried over MgSO4
filtrationfiltered
concentrationconcentrated
customThe residue was purified by flash chromatography on silica gel eluting with 0 to 2% ethyl acetate in dichloromethane
customThe solvent was evaporated to dryness

Sources & evidence

ORD record: ord-1992ebb7709840239c92dbdc8e8e50f8
Source dataset: uspto-grants-2010_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07718653B2

Reaction notes

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