Piperazine → 1-(5-Trifluoromethyl-pyridin-2-yl)-piperazine

HRID 1416275Notes

Reaction equation

HRID 1416275 reaction equation
Cl[C:2]1[CH:7]=[CH:6][C:5]([C:8]([F:11])([F:10])[F:9])=[CH:4][N:3]=1.[NH:12]1[CH2:17][CH2:16][NH:15][CH2:14][CH2:13]1>O>[F:9][C:8]([F:11])([F:10])[C:5]1[CH:6]=[CH:7][C:2]([N:12]2[CH2:17][CH2:16][NH:15][CH2:14][CH2:13]2)=[N:3][CH:4]=1

Participants

4

Reactant 2

HCID 4837PiperazineHCID 923422-Chloro-5-(trifluoromethyl)pyridine

Product 1

HCID 6676181-(5-Trifluoromethyl-pyridin-2-yl)-piperazineYield 75.2%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
100 °C

Procedure

A mixture of 2-chloro-5-trifluoromethylpyridine (Aldrich; 2.296 g), piperazine (5.45 g), and water is heated at 100° C. for 16 h. After cooling, the mixture is partitioned between dichloromethane and aq. sodium bicarbonate. The organic layers are dried over sodium sulfate and concentrated. The residue is chromatographed on silica gel using methanol/dichloromethane (8/92) with about 0.5% ammonium hydroxide present, to give 2.20 g of 1-(5-trifluoromethylpyridin-2-yl)piperazine; mp 45-47° C.; IR (mineral oil) 1127, 1323, 1319, 1118, 1614 cm-1 ; 1H NMR (CDCl3) δ2.98, 3.62, 6.63, 7.62, 8.40.

Workup

  1. temperatureAfter cooling
  2. customthe mixture is partitioned between dichloromethane and aq. sodium bicarbonate
  3. dry with materialThe organic layers are dried over sodium sulfate
  4. concentrationconcentrated
  5. customThe residue is chromatographed on silica gel

Sources & evidence

ORD record
ord-4a68f93665f64a51bad6382e78a058df
Source dataset
uspto-grants-1999_06
Patent number
US05912246

Reaction notes

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