Diisopropylethylamine → 1-Tert-butyl 3-methyl 4-(2-cyano-4-nitrophenyl)piperazine-1,3-dicarboxylate

HRID 2279213Notes

Reaction equation

HRID 2279213 reaction equation
[N:1]1([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[CH2:6][CH2:5][NH:4][CH:3]([C:7]([O:9][CH3:10])=[O:8])[CH2:2]1.C(N(CC)C(C)C)(C)C.F[C:28]1[CH:35]=[CH:34][C:33]([N+:36]([O-:38])=[O:37])=[CH:32][C:29]=1[C:30]#[N:31]>O1CCCC1>[C:30]([C:29]1[CH:32]=[C:33]([N+:36]([O-:38])=[O:37])[CH:34]=[CH:35][C:28]=1[N:4]1[CH2:5][CH2:6][N:1]([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[CH2:2][CH:3]1[C:7]([O:9][CH3:10])=[O:8])#[N:31]

Participants

5

Procedure

To a solution of 1-tert-butyl 3-methyl piperazine-1,3-dicarboxylate (80 g, 328 mmol) and N,N-diisopropylethylamine (192 mL, 741 mmol) in 300 mL of dry tetrahydrofuran was added 2-fluoro-5-nitrobenzonitrile (36 g, 219 mmol) at room temperature. The reaction mixture was heated to reflux for 36 hours. The reaction was concentrated and the resulting residue was purified by silica gel chromatography (30% ethyl acetate in hexane) to give the title compound: 1H NMR (300 MHz, DMSO-d6) δ ppm 1.41 (s, 9H), 3.01-3.15 (m, 1H), 3.29-3.36 (m, 1H), 3.34-3.36 (m, 1H), 3.48-3.55 (m, 1H), 3.66 (s, 3H), 3.72-3.76 (m, 1H), 4.43-7.48 (m, 1H), 4.96-4.98 (m, 1H), 7.30 (d, J=9.1 Hz, 1H), 8.32 (dd, J=9.5, 2.8 Hz, 1H), 8.55 (d, J=2.8 Hz, 1H); MS (DCI/NH3) m/z 391 (M+H)+.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux for 36 hours
  3. concentrationThe reaction was concentrated
  4. customthe resulting residue was purified by silica gel chromatography (30% ethyl acetate in hexane)

Sources & evidence

ORD record
ord-d76257e06932495682041b76ec889b87
Source dataset
uspto-grants-2015_09
Patent number
US09133206B2

Reaction notes

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