Trifluoroacetic acid → 1-(3-Methoxy-4-nitrophenyl)piperazine

HRID 419392Notes

Reaction equation

HRID 419392 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([N:12]2[CH2:17][CH2:16][N:15](C(OC(C)(C)C)=O)[CH2:14][CH2:13]2)[CH:6]=[CH:7][C:8]=1[N+:9]([O-:11])=[O:10].C(O)(C(F)(F)F)=O>C(Cl)Cl>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([N:12]2[CH2:17][CH2:16][NH:15][CH2:14][CH2:13]2)[CH:6]=[CH:7][C:8]=1[N+:9]([O-:11])=[O:10]

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 25918710Tert-butyl 4-(3-methoxy-4-nitrophenyl)piperazine-1-carboxylate

Product 1

HCID 39674091-(3-Methoxy-4-nitrophenyl)piperazineYield 97.4%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

1,1-Dimethylethyl 4-[3-(methyloxy)-4-nitrophenyl]-1-piperazinecarboxylate (combined batches) (5.16 g, 15.3 mmol) in DCM was cooled with an ice/H2O bath and TFA (30.0 mL, 398 mmol) was added dropwise via an addition funnel. Upon completion by TLC, the reaction was quenched slowly with 1N NaOH until the aqueous layer was basic as determined by pH paper. The mixture was extracted with DCM, dried (MgSO4) and concentrated to provide the title compound of step B (3.52 g, 14.9 mmol, 97%). 1H NMR (400 MHz, DMSO-d6) δ ppm 2.34 (br. s., 1H), 2.73-2.77 (m, 4H), 3.26-3.33 (m, 4H), 3.85 (s, 3H), 6.45 (d, J=2.4 Hz, 1H), 6.52 (dd, J=9.4, 2.5 Hz, 1H), 7.83 (d, J=9.3 Hz, 1H).

Workup

  1. customUpon completion by TLC, the reaction was quenched slowly with 1N NaOH until the aqueous layer
  2. extractionThe mixture was extracted with DCM
  3. dry with materialdried (MgSO4)
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-6b2539dd97ea4e638ddf2a4c836ed2f5
Source dataset
uspto-grants-2012_01
Patent number
US08093239B2

Reaction notes

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