Potassium Carbonate → Tert-butyl 4-(2-chloro-4-nitrophenyl)piperazine-1-carboxylate

HRID 1503832Notes

Reaction equation

Br[C:2]1[CH:7]=[CH:6][C:5]([N+:8]([O-:10])=[O:9])=[CH:4][C:3]=1[Cl:11].[N:12]1([C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[CH2:17][CH2:16][NH:15][CH2:14][CH2:13]1.C(=O)([O-])[O-].[K+].[K+]>[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.CS(C)=O.O>[Cl:11][C:3]1[CH:4]=[C:5]([N+:8]([O-:10])=[O:9])[CH:6]=[CH:7][C:2]=1[N:15]1[CH2:14][CH2:13][N:12]([C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[CH2:17][CH2:16]1

Participants

Conditions

Temperature: 125 °C

Procedure

A mixture of 1-bromo-2-chloro-4-nitrobenzene (1 g, 4.2 mmol), tert-butyl piperazine-1-carboxylate (0.86 g, 4.6 mmol), potassium carbonate (878 mg, 6.4 mmol) and tetrabutyl ammonium bromide (137 mg, 0.42 mmol) in dimethylsulfoxide (20 mL) was heated at 125° C. for 3 hours. After cooling to ambient temperature, the mixture was diluted with water and extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered, and concentrated. The residue was purified by flash chromatography on silica gel eluting with 5/1 petroleum ether/ethyl acetate to give the title compound. MS: 342 (M+H+)

Workup

temperatureAfter cooling to ambient temperature
extractionextracted with ethyl acetate
washThe organic layer was washed with brine
dry with materialdried over anhydrous sodium sulfate
filtrationfiltered
concentrationconcentrated
customThe residue was purified by flash chromatography on silica gel eluting with 5/1 petroleum ether/ethyl acetate

Sources & evidence

ORD record: ord-2e226740e29b46618a14f04d69b57eed
Source dataset: uspto-grants-2015_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09212192B2

Reaction notes

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