Diethyl Ether → Tert-butyl 4-(4-amino-3-methoxyphenyl)piperazine-1-carboxylate

HRID 705722Notes

Reaction equation

HRID 705722 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([N:12]2[CH2:17][CH2:16][N:15]([C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[CH2:14][CH2:13]2)[CH:6]=[CH:7][C:8]=1[N+:9]([O-])=O.C(OCC)C>CO.C(OCC)(=O)C.[Pd]>[NH2:9][C:8]1[CH:7]=[CH:6][C:5]([N:12]2[CH2:17][CH2:16][N:15]([C:18]([O:20][C:21]([CH3:22])([CH3:23])[CH3:24])=[O:19])[CH2:14][CH2:13]2)=[CH:4][C:3]=1[O:2][CH3:1]

Participants

6

Reactant 2

HCID 3283Diethyl EtherHCID 25918710Tert-butyl 4-(3-methoxy-4-nitrophenyl)piperazine-1-carboxylate

Product 1

HCID 67128946Tert-butyl 4-(4-amino-3-methoxyphenyl)piperazine-1-carboxylateYield 89.6%

Reagents, catalysts & solvents 3

HCID 23938PalladiumCatalystHCID 887MethanolSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of tert-butyl 4-(3-methoxy-4-nitrophenyl)piperazine-1-carboxylate (I1) (1.90 g, 5.63 mmol) in methanol (20 mL) and ethyl acetate (80 mL) was added 10% Pd/C (0.500 g). The mixture was evacuated and backfilled three times with hydrogen gas then stirred under a hydrogen atmosphere for 18 hours. The crude reaction mixture was filtered through a plug of Celite, washing with ethyl acetate and the filtrate evaporated in vacuo then dried under high vacuum to give a dark red viscous oil. The oil was suspended in a 2:1 solution of diethyl ether and petroleum ether (15 mL) and sonicated for 3 minutes. The resulting mixture was evaporated in vacuo and dried under high vacuum to give the title compound (I2) (1.55 g, 89%) as a dark red solid; 1H NMR (300 MHz, d6-DMSO) δ 1.47 (s, 9H), 2.97 (t, 4H, J=4.7 Hz), 3.57 (t, 4H, J=4.7 Hz), 3.83 (s, 3H), 6.40 (dd, 1H, J=8.3, 2.1 Hz), 6.50 (d, 1H, J=2.0 Hz) and 6.64 (d, 1H, J=8.3 Hz). LCMS Method B: rt 5.02 min; m/z 308.3 [M+H]+.

Workup

  1. customThe mixture was evacuated
  2. customThe crude reaction mixture
  3. filtrationwas filtered through a plug of Celite
  4. washwashing with ethyl acetate
  5. customthe filtrate evaporated in vacuo
  6. customthen dried under high vacuum
  7. customto give a dark red viscous oil
  8. customsonicated for 3 minutes
  9. customThe resulting mixture was evaporated in vacuo
  10. customdried under high vacuum

Sources & evidence

ORD record
ord-0581653fed874832abf4c45263082557
Source dataset
uspto-grants-2015_11
Patent number
US09174946B2

Reaction notes

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