Potassium Carbonate → 1-Methyl-4-(3-nitrobenzyl)piperazine

HRID 1989027Notes

Reaction equation

[N+:1]([C:4]1[CH:5]=[C:6]([CH:9]=[CH:10][CH:11]=1)[CH2:7]Br)([O-:3])=[O:2].[CH3:12][N:13]1[CH2:18][CH2:17][NH:16][CH2:15][CH2:14]1.C(=O)([O-])[O-].[K+].[K+]>CN(C=O)C>[CH3:12][N:13]1[CH2:18][CH2:17][N:16]([CH2:7][C:6]2[CH:9]=[CH:10][CH:11]=[C:4]([N+:1]([O-:3])=[O:2])[CH:5]=2)[CH2:15][CH2:14]1

Participants

Conditions

Temperature: 90 °C

Procedure

m-Nitrobenzyl bromide (500 mg, 2.31 mmol) was added to a mixture of 1-methylpiperazine (277 mg, 2.77 mmol) and potassium carbonate (414 g, 3.0 mmol) in 5 mL of DMF. The mixture was stirred at 90° C. for 16 hours. After cooling to room temperature, the mixture was extracted into ethyl acetate (EtOAc), washed with water, brine and then dried with sodium sulfate (Na2SO4). Removal of the solvent and chromatography on silica, eluting with EtOAc/CH3OH/NH4OH (10:1:0.1, v/v), gave 510 mg of 1-methyl-4-(3-nitro-benzyl)-piperazine, which was converted to the title compound under normal hydrogenation conditions. The titled compound was obtained as a yellow solid (450 mg, 95%). 1H NMR (400 MHz, CDCl3) δ (ppm): 7.02 (t, J=7.6 Hz, 1H), 6.62 (s, 1H), 6.60 (d, J=7.6 Hz, 1H), 6.54 (d, J=7.6 Hz, 1H), 3.43 (s, 2H), 2.76 (br, 4H), 2.65 (br, 4H), 2.82 (m, 4H), 2.46 (s, 3H).

Workup

temperatureAfter cooling to room temperature
extractionthe mixture was extracted into ethyl acetate (EtOAc)
washwashed with water, brine
dry with materialdried with sodium sulfate (Na2SO4)
customRemoval of the solvent and chromatography on silica
washeluting with EtOAc/CH3OH/NH4OH (10:1:0.1

Sources & evidence

ORD record: ord-5a86f034f58444d385de5bfe85e63b49
Source dataset: uspto-grants-2010_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07642270B2

Reaction notes

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