Diisopropylethylamine → Ethyl 4-(6-(trifluoromethyl)pyridin-2-yl)piperazine-2-carboxylate

HRID 1184573Notes

Reaction equation

Br[C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([C:8]([F:11])([F:10])[F:9])[N:3]=1.[NH:12]1[CH2:17][CH2:16][NH:15][CH2:14][CH:13]1[C:18]([O:20][CH2:21][CH3:22])=[O:19].C(N(CC)C(C)C)(C)C>CS(C)=O>[F:9][C:8]([F:11])([F:10])[C:4]1[N:3]=[C:2]([N:15]2[CH2:16][CH2:17][NH:12][CH:13]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[CH2:14]2)[CH:7]=[CH:6][CH:5]=1

Participants

Conditions

Temperature: 80 °C

Procedure

2-Bromo-6-(trifluoromethyl)pyridine (13.56 g, 60 mmol) and ethyl piperazine-2-carboxylate (U.S. Patent App. Publ. US2004/0147559, 9.49 g, 60.0 mmol) were mixed in dry dimethyl sulfoxide (40 mL) and then treated with N,N-diisopropylethylamine (31.1 mL, 180 mmol). The mixture was heated to 80° C. and stirred for 4 days. The solution was concentrated, and the residue was purified on a silica gel column (hexane:ethyl acetate=1:3) to give the title compound. 1H NMR (300 MHz, methanol-d4) δ ppm 1.27 (t, 3H, J=7 Hz), 2.83 (ddd, 1H, J=12, 9, 3 Hz), 3.11 (ddd, 1H, J=12, 5, 3 Hz), 3.33-3.38 (m, 1 H), 3.41-3.50 (m, 1 H), 3.56-3.62 (m, 1 H), 3.81 (ddd, 1H, J=13, 4, 3 Hz), 4.15-4.25 (m, 3 H), 7.00 (t, 2H, J=8 Hz), 7.65-7.75 (m, 1 H); MS (DCI) m/z 304 (M+H)+.

Workup

concentrationThe solution was concentrated
customthe residue was purified on a silica gel column (hexane:ethyl acetate=1:3)

Sources & evidence

ORD record: ord-ff731d27350d4d429c5e8acaac3e7aae
Source dataset: uspto-grants-2014_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08669255B2

Reaction notes

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