Potassium Carbonate → 4-nitro-2-(2-piperidin-1-ylethyl)-2H-indazole

HRID 1825818Notes

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+].Cl.Cl[CH2:21][CH2:22][N:23]1[CH2:28][CH2:27][CH2:26][CH2:25][CH2:24]1>CN(C)C=O>[N+:1]([C:4]1[C:5]2[C:9]([CH:10]=[CH:11][CH:12]=1)=[N:8][N:7]([CH2:21][CH2:22][N:23]1[CH2:28][CH2:27][CH2:26][CH2:25][CH2:24]1)[CH:6]=2)([O-:3])=[O:2]

Participants

Conditions

Temperature: 60 °C

Procedure

4-Nitroindazole (1.00 g, 6.14 mmol) was dissolved in 20 mL of N,N-dimethylformamide and potassium carbonate (2.50 g, 18.1 mmol) was added. The mixture was stirred for 30 minutes and then 1-(2-chloro-ethyl)-piperidine hydrochloride (1.73 g, 9.40 mmol) was added. The mixture was heated to 60° C. for 6 hours, cooled to room temperature, the mixture was filtered through a plug of silica gel and rinsed with triethylamine/ethyl acetate (1/4). The filtrate was concentrated in vacuo to remove N,N-dimethylformamide and the residue purified by flash chromatography (silica gel, triethylamine/ethyl acetate 1/30). 1H NMR (300 MHz, DMSO-D6) δ ppm 1.37 (m, 2 H) 1.45 (m, 4 H) 2.42 (m, 4 H) 2.85 (t, J=6.44 Hz, 2 H) 4.66 (t, J=6.61 Hz, 2 H) 7.49 (m, 1 H) 8.19 (m, 2 H) 8.91 (s, 1 H); MS (DCI/NH3) m/z 275 [M+H]+.

Workup

temperaturecooled to room temperature
filtrationthe mixture was filtered through a plug of silica gel
washrinsed with triethylamine/ethyl acetate (1/4)
concentrationThe filtrate was concentrated in vacuo
customto remove N,N-dimethylformamide
customthe residue purified by flash chromatography (silica gel, triethylamine/ethyl acetate 1/30)

Sources & evidence

ORD record: ord-da6d8dc870b34fbba194d23b29559da7
Source dataset: uspto-grants-2006_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07049307B2

Reaction notes

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