Potassium Carbonate → Tert-butyl 4-(3-chloropyridin-2-yl)piperazine-1-carboxylate

HRID 912763Notes

Reaction equation

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

Participants

Conditions

Temperature: 120 °C

Procedure

A mixture of 2,3-dichloropyridine (10 g, 67.5 mmol, Aldrich), tert-butyl 1-piperazinecarboxylate (12.58 g, 67.5 mmol, Aldrich), copper powder (0.5 g, 7.8 mmol) and K2CO3 (9.33 g, 67.5 mmol) in DMF (100 mL) was stirred at 120° C. for 16 h. The reaction mixture was cooled to room temperature, concentrated in vacuo and the residue was dissolved in EtOAc (200 mL). The organic solution was washed with saturated aqueous solution of NaHCO3 (50 mL) and brine (50 mL), dried over Na2SO4, and filtered. The solvent was removed in vacuo and the residue was purified by silica gel column chromatography, eluting with 15% EtOAc/hexane, to give the title compound as an orange oil. MS (ESI, pos. ion) m/z: 298 (M+1).

Workup

temperatureThe reaction mixture was cooled to room temperature
concentrationconcentrated in vacuo
dissolutionthe residue was dissolved in EtOAc (200 mL)
washThe organic solution was washed with saturated aqueous solution of NaHCO3 (50 mL) and brine (50 mL)
dry with materialdried over Na2SO4
filtrationfiltered
customThe solvent was removed in vacuo
customthe residue was purified by silica gel column chromatography
washeluting with 15% EtOAc/hexane

Sources & evidence

ORD record: ord-525e89e0db04423b8ae69121722b1efc
Source dataset: uspto-grants-2011_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08026241B2

Reaction notes

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