Potassium Carbonate → 4-Boc-1-(5-bromo-2-pyridyl)piperazine

HRID 2403570Notes

Reaction equation

[Br:1][C:2]1[CH:3]=[CH:4][C:5](F)=[N:6][CH:7]=1.C([O-])([O-])=O.[K+].[K+].[N:15]1([C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22])[CH2:20][CH2:19][NH:18][CH2:17][CH2:16]1>CN(C=O)C>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([N:18]2[CH2:17][CH2:16][N:15]([C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22])[CH2:20][CH2:19]2)=[N:6][CH:7]=1

Participants

Conditions

Temperature: 130 °C

Procedure

5-Bromo-2-fluoropyridine (3.0 g) was dissolved in DMF (18 ml), and K2CO3 (1.31 g) and tert-butyl piperazine-1-carboxylate (1.76 g) were added thereto, followed by stirring at 130° C. for 3 days. The reaction mixture was concentrated under reduced pressure, and then a saturated aqueous sodium hydrogen carbonate solution was added thereto, followed by extraction with CHCl3. The organic layer was dried over Na2SO4 and the solvent was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (hexane/EtOAc) to obtain tert-butyl 4-(5-bromopyridin-2-yl)piperazine-1-carboxylate (1.21 g).

Workup

concentrationThe reaction mixture was concentrated under reduced pressure
additiona saturated aqueous sodium hydrogen carbonate solution was added
extractionfollowed by extraction with CHCl3
dry with materialThe organic layer was dried over Na2SO4
concentrationthe solvent was concentrated under reduced pressure
customThe obtained residue was purified by silica gel column chromatography (hexane/EtOAc)

Sources & evidence

ORD record: ord-74479b55d24d4a50b6a7ec2930dd5bb3
Source dataset: uspto-grants-2014_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08802679B2

Reaction notes

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