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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 1900555Generated: October 30, 2026

Piperazine → 1-(5-Chloropyridin-2-yl)piperazine

https://huagongshe.com/reaction/1900555

Reaction equation

Participants

RoleNameHCIDCharge
ReactantPiperazineHCID 4837—
Reactant2,5-DichloropyridineHCID 27685—
SolventDichloromethaneHCID 6344—
Product1-(5-Chloropyridin-2-yl)piperazineHCID 380530192%

Reaction Conditions

Temperature165 °C

Reaction Steps

A mixture of 2,5-dichloropyridine (10.0 g, 67.6 mmol) and piperazine (58.1 g, 675 mmol) was stirred at 165° C. for 2 H. The mixture was allowed to cool, slurried with dichloromethane (200 ml) and the solid collected by filtration. The filtrate was concentrated in vacuo and the procedure repeated. The residue after concentration of the filtrate was purified by flash chromatography twice (eluting with 1% ammonia, 10% methanol in dichloromethane) to give 1-(5-chloro-2-pyridyl)piperazine (12.25 g, 92%) as a tan solid. A portion of this solid (0.484 g, 2.45 mmol) was added to a solution of 3-dimethylaminomethyl-1H-pyrrolo[2,3-b]pyridine (0.392 g, 2.24 mmol) in toluene (10 ml) and the mixture heated at reflux under nitrogen for 6 h. The mixture was allowed to cool and the crystallised product filtered off. Recrystallisation from toluene gave the title compound (0.229 g, 31%), m.p. 196°-198° C.; (Found: C, 63.16; H, 5.60; N, 21.18. C17H18ClN5. 0.1PhMe requires C, 63.08; H, 5.62; N, 20.78%); δH (DMSO-d6) 2.46 (4H, t, J 5.0 Hz, 2×piperazinyl CH2), 3.45 (4H, t, J 5.0 Hz, 2×piperazinyl CH2), 3.67 (2H, s, CH2N), 6.82 (1H, d, J 9.1 Hz, 3'-H), 7.04 (1H, dd, J 7.8, 4.6 Hz, 5-H), 7.37 (1H, d, J 2.1 Hz, 2-H), 7.56 (1H, dd, J 9.1, 2.7 Hz, 4'-H), 8.05 (1H, dd, J 7.8, 1.4 Hz, 4-H), 8.08 (1H, d, J 2.7 Hz, 6'-H), 8.19 (1H, dd, J 4.6, 1.4 Hz, 6-H), and 11.46 (1H, br s, NH); m/z (CI+, NH3) 328 [(M+H)+, ±Cl].

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS05576319
Source datasetuspto-grants-1996_11
ORD IDord-85fd68f1665e4f5abeeee8269f95d4f0
Source noteuspto-grants-1996_11