Dichloromethane → 1-(2-Chloro-6-nitrophenyl)piperazine

HRID 970121Notes

Reaction equation

HRID 970121 reaction equation
C(OC([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[C:19]([N+:20]([O-:22])=[O:21])=[CH:18][CH:17]=[CH:16][C:15]=2[Cl:23])[CH2:10][CH2:9]1)=O)(C)(C)C.C(Cl)Cl>FC(F)(F)C(O)=O>[Cl:23][C:15]1[CH:16]=[CH:17][CH:18]=[C:19]([N+:20]([O-:22])=[O:21])[C:14]=1[N:11]1[CH2:12][CH2:13][NH:8][CH2:9][CH2:10]1

Participants

4

Reactant 2

HCID 6344DichloromethaneHCID 587677041-Boc-4-(2-chloro-6-nitrophenyl)piperazine

Product 1

HCID 27714081-(2-Chloro-6-nitrophenyl)piperazineYield 95.3%

Reagents, catalysts & solvents 1

HCID 6422Trifluoroacetic acidSolvent

Procedure

4-(2-Chloro-6-nitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (1.87 g, 5.47 mmol) was dissolved in trifluoroacetic acid (5.0 mL) and CH2Cl2 (5.0 mL) and allowed to stir for 2 h. The reaction mixture was concentrated, diluted with EtOAc, and washed with saturated aq. NaHCO3. The organic layer was dried over Na2SO4, concentrated and purified by column chromatography (silica, 100% CH2Cl2) to afford 1-(2-chloro-6-nitro-phenyl)-piperazine (1.26 g, 95%). MS (electrospray): exact mass calculated for C10H12ClN3O2, 241.1; m/z found, 242.1 [M+H]+. 1H NMR (400 MHz, CDCl3): 7.54 (dd, J=8.2, 1.6 Hz, 1H), 7.49 (dd, J=8.2, 1.6 Hz, 1H), 7.10 (t, J=8.2 Hz, 1H), 3.08 (br s, 4H), 2.99 (br s, 4H), 2.07-2.12 (m, 1H).

Workup

  1. concentrationThe reaction mixture was concentrated
  2. additiondiluted with EtOAc
  3. washwashed with saturated aq. NaHCO3
  4. dry with materialThe organic layer was dried over Na2SO4
  5. concentrationconcentrated
  6. custompurified by column chromatography (silica, 100% CH2Cl2)

Sources & evidence

ORD record
ord-062c214a9fdc46ea9c3c8a5f0ccc4e6d
Source dataset
uspto-grants-2007_12
Patent number
US07309703B2

Reaction notes

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