Piperazine → 1-(5-Bromopyridin-2-yl)piperazine
Reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([Br:8])=[CH:4][N:3]=1.[NH:9]1[CH2:14][CH2:13][NH:12][CH2:11][CH2:10]1>>[Br:8][C:5]1[CH:6]=[CH:7][C:2]([N:9]2[CH2:14][CH2:13][NH:12][CH2:11][CH2:10]2)=[N:3][CH:4]=1Participants
3
Procedure
A mixture of 2,5-dibromopyridine (10.00 g, 42.21 mmol) and piperazine (7.98 g, 92.79 mmol) were heated as a melt at 125° for 3 h. On cooling to room temperature the mixture was triturated with 10% methanol-dichloromethane and filtered. The filtrate was evaporated and the residue subjected to column chromatography (silica, 5-8% methanol-dichloromethane) to afford the 5-bromo-2-(1-piperazinyl)pyridine (7.00 g) as a beige solid δH (CDCl3) 2.75 (1H, br s), 2.97 (4H, m), 3.47 (4H, m), 6.52 (1H, d, J 9.1 Hz), 7.52 (1H, dd, J 9.1, 2.1 Hz), and 8.18 (1H, d, J 2.1 Hz).
Workup
- temperaturewere heated as a melt at 125° for 3 h
- customwas triturated with 10% methanol-dichloromethane
- filtrationfiltered
- customThe filtrate was evaporated
Sources & evidence
- ORD record
- ord-778b8d892e034ff185fe310a099e5639
- Source dataset
- uspto-grants-2003_04
- Patent number
- US06552029B1
Reaction notes
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