Cesium carbonate → Tert-butyl 4-(4-chloro-2-methylphenyl)piperazine-1-carboxylate

HRID 457160Notes

Reaction equation

Br[C:2]1[CH:7]=[CH:6][C:5]([Cl:8])=[CH:4][C:3]=1[CH3:9].[N:10]1([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[CH2:15][CH2:14][NH:13][CH2:12][CH2:11]1.C(P(C(C)(C)C)C(C)(C)C)(C)(C)C.C(=O)([O-])[O-].[Cs+].[Cs+]>C1(C)C=CC=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd]>[C:19]([O:18][C:16]([N:10]1[CH2:15][CH2:14][N:13]([C:2]2[CH:7]=[CH:6][C:5]([Cl:8])=[CH:4][C:3]=2[CH3:9])[CH2:12][CH2:11]1)=[O:17])([CH3:22])([CH3:20])[CH3:21]

Participants

Conditions

Temperature: 80 °C

Procedure

2-Bromo-5-chlorotoluene (0.82 g, 4 mmol) and tert-Butyl 1-piperazine carboxylate (0.89 g, 2.32 mmol) were added to a solution of tri-t-butyl phosphine (0.033 g, 4 mmol %), tris(dibenzylideneacetone)dipalladium(0) (0.075 g, 2.0 mmol %) and cesium carbonate (1.95 g, 6.0 mmol) in toluene and heated to 80° C. overnight. The reaction mixture was filtered through celite and concentrated in vacuo. The crude product was purified on silica gel (gradient elution from 20% ethyl acetate/hexane to 50% ethyl acetate/hexane) to give the title compound in 20% yield. ESI-MS m/z: 311 (M+1), UV retention time: 3.49 min.

Workup

filtrationThe reaction mixture was filtered through celite and
concentrationconcentrated in vacuo
customThe crude product was purified on silica gel (gradient elution from 20% ethyl acetate/hexane to 50% ethyl acetate/hexane)

Sources & evidence

ORD record: ord-6b5c1f8277504c4689871d4a49871d23
Source dataset: uspto-grants-2007_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07186729B2

Reaction notes

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