Piperazine → 1-(4-(Trifluoromethyl)phenyl)piperazine

HRID 1772266Notes

Reaction equation

Br[C:2]1[CH:7]=[CH:6][C:5]([C:8]([F:11])([F:10])[F:9])=[CH:4][CH:3]=1.[NH:12]1[CH2:17][CH2:16][NH:15][CH2:14][CH2:13]1.C(O[Na])(C)(C)C>C1(C)C=CC=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd].C1C=CC(P(C2C(C3C(P(C4C=CC=CC=4)C4C=CC=CC=4)=CC=C4C=3C=CC=C4)=C3C(C=CC=C3)=CC=2)C2C=CC=CC=2)=CC=1>[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)=[CH:3][CH:4]=1

Participants

Conditions

Temperature: 70 °C

Procedure

The mixture of 1-bromo-4-(trifluoromethyl)benzene (15 g, 67 mmol), piperazine (28.8 g, 334.4 mmol, 5 eq.), Pd2(dba)3 (1.4 g, 1.53 mmol, 2 mol %), BINAP (420 mg, 0.67 mmol, 1 mol %) and t-BuONa (12.9 g, 134.2 mmol, 2 eq.) in toluene (200 ml) was stirred for 2 hours at 70° C. under nitrogen. Then the solids were filtered off and the mixture was concentrated under vacuum to give a residue, which was purified by silica gel column chromatography using 1% 5% methanol in dichloromethane to afford 1-[4-(trifluoromethyl)phenyl]piperazine as a dark red solid (10.5 g, 68%). (ES, m/z): [M+H]+ 231.1; 1H NMR (300 MHz, CDCl3): δ 7.48 (d, J=8.7 Hz, 2H), 6.92 (d, J=8.7 Hz, 2H), 3.32-3.20 (m, 4H), 3.04-3.01 (m, 4H).

Workup

filtrationThen the solids were filtered off
concentrationthe mixture was concentrated under vacuum
customto give a residue, which
customwas purified by silica gel column chromatography

Sources & evidence

ORD record: ord-d11d002d5e3d437f8065c2ace5f0418f
Source dataset: uspto-grants-2016_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09249102B2

Reaction notes

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