Hydrochloric Acid → 3-(4-Aminophenyl)-4-methylpiperazin-2-one

HRID 1772091Notes

Reaction equation

HRID 1772091 reaction equation
[CH3:1][N:2]1[CH2:7][CH2:6][NH:5][C:4](=[O:8])[CH:3]1[C:9]1[CH:14]=[CH:13][C:12]([N+:15]([O-])=O)=[CH:11][CH:10]=1.Cl.C(=O)([O-])[O-].[K+].[K+]>[Fe].C(O)C>[NH2:15][C:12]1[CH:11]=[CH:10][C:9]([CH:3]2[N:2]([CH3:1])[CH2:7][CH2:6][NH:5][C:4]2=[O:8])=[CH:14][CH:13]=1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 11430Potassium CarbonateHCID 666098864-Methyl-3-(4-nitrophenyl)piperazine-2-one

Product 1

HCID 666098603-(4-Aminophenyl)-4-methylpiperazin-2-oneYield 100%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 702EthanolSolvent

Procedure

A 25-mL single-neck round-bottomed flask equipped with a reflux condenser and magnetic stirrer was purged with nitrogen and charged with 104b (210 mg, 0.89 mmol), ethanol (6 mL), iron powder (−325 mesh, 491 mg, 8.93 mmol) and 2N hydrochloric acid (0.70 mL, 1.40 mmol), and the mixture was heated at reflux for 30 min. After this time, the reaction was cooled to room temperature, and powdered potassium carbonate (3.03 g, 22.0 mmol) was added. The resulting suspension was filtered and the filter cake washed with ethanol (4×10 mL). The filtrate was concentrated under reduced pressure to afford 104c in 100% yield (185 mg) as a white solid: mp 153-154° C.; 1H NMR (300 MHz, DMSO-d6) δ 7.74 (d, 1H, J=2.7 Hz), 6.90 (d, 2H, J=8.4 Hz), 6.47 (d, 2H, J=8.4 Hz), 4.95 (bs, 2H), 3.45 (m, 1H), 3.42 (s, 1H), 3.14 (m, 1H), 2.89 (m, 1H), 2.44 (m, 1H), 2.02 (s, 3H); MS (ESI+) m/z 206 (M+H).

Workup

  1. customA 25-mL single-neck round-bottomed flask equipped with a reflux condenser and magnetic stirrer
  2. customwas purged with nitrogen
  3. temperaturethe mixture was heated
  4. temperatureat reflux for 30 min
  5. filtrationThe resulting suspension was filtered
  6. washthe filter cake washed with ethanol (4×10 mL)
  7. concentrationThe filtrate was concentrated under reduced pressure

Sources & evidence

ORD record
ord-19db17a772694d148d257106df5ac8b0
Source dataset
uspto-grants-2016_02
Patent number
US09249123B2

Reaction notes

Loading…