Potassium Carbonate → 3-bromo-6-nitro-1-(2-pyrrolidin-1-yl-ethyl)-1H-indazole

HRID 1790171Notes

Reaction equation

[Br:1][C:2]1[C:10]2[C:5](=[CH:6][C:7]([N+:11]([O-:13])=[O:12])=[CH:8][CH:9]=2)[NH:4][N:3]=1.C(=O)([O-])[O-].[K+].[K+].Cl[CH2:21][CH2:22][N:23]1[CH2:27][CH2:26][CH2:25][CH2:24]1>CN(C=O)C>[Br:1][C:2]1[C:10]2[C:5](=[CH:6][C:7]([N+:11]([O-:13])=[O:12])=[CH:8][CH:9]=2)[N:4]([CH2:21][CH2:22][N:23]2[CH2:27][CH2:26][CH2:25][CH2:24]2)[N:3]=1

Participants

Conditions

Temperature: 50 °C

Procedure

A mixture of 3-bromo-6-nitro-1H-indazole (1.0 g, 4.1 mmol) and potassium carbonate (2.9 g 21 mmol) in DMF (20 mL) was stirred for 30 minutes after which 1-(2-chloro-ethyl)-pyrrolidine (1.8 g, 10 mmol) was added. The mixture was heated to 50° C. for 6 hours, cooled to room temperature and filtered through a plug of silica gel which was rinsed with triethylamine/ethyl acetate (1/4). The filtrate was concentrated under reduced pressure and purified by flash chromatography (silica gel, triethylamine/ethyl acetate 1/30) to provide the title compound (900 mg, 64%). 1H NMR (300 MHz, DMSO-d6) ppm 1.61 (m, 4H), 2.47 (m, 4H), 2.90 (t, 2H, J=6.44), 4.69 (t, J=6.44, 2H), 7.82 (m, 1H), 8.02 (m, 1H), 8.86 (m, 1H); MS (DCI/NH3) m/z 339 [M+H]+.

Workup

additionwas added
temperaturecooled to room temperature
filtrationfiltered through a plug of silica gel which
washwas rinsed with triethylamine/ethyl acetate (1/4)
concentrationThe filtrate was concentrated under reduced pressure
custompurified by flash chromatography (silica gel, triethylamine/ethyl acetate 1/30)

Sources & evidence

ORD record: ord-d525da7ec79f45ea8aa85457cb1368cd
Source dataset: uspto-grants-2006_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07071182B2

Reaction notes

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