Sodium Carbonate → HCID 68461115, compound

HRID 970138Notes

Reaction equation

HRID 970138 reaction equation
Br[C:2]1[C:12]([N+:13]([O-:15])=[O:14])=[CH:11][CH:10]=[CH:9][C:3]=1[C:4]([O:6][CH2:7]C)=[O:5].[C:16]([O:20][C:21]([N:23]1[CH2:28][CH2:27][NH:26][CH2:25][CH2:24]1)=[O:22])([CH3:19])([CH3:18])[CH3:17].C([O-])([O-])=O.[Na+].[Na+]>C(O)CCC>[C:16]([O:20][C:21]([N:23]1[CH2:28][CH2:27][N:26]([C:2]2[C:12]([N+:13]([O-:15])=[O:14])=[CH:11][CH:10]=[CH:9][C:3]=2[C:4]([O:6][CH3:7])=[O:5])[CH2:25][CH2:24]1)=[O:22])([CH3:19])([CH3:17])[CH3:18]

Participants

5

Procedure

To a stirred solution of 736 mg (2.83 mmol) of ethyl 2-bromo-3-nitrobenzoate and 579 mg (3.1 mmol, 1.1 eq) of 1-tert-butyloxycarbonylpiperazine in n-butanol (6 mL) was added 330 mg (3.1 mmol, 1.1 eq) of Na2CO3. The mixture was heated to reflux for 4 h. The solvent was removed under reduced pressure. The crude product was partitioned between EtOAc (100 mL) and 20 mL of H2O. The organic layer was washed with H2O (2×20 mL), dried over Na2SO4 and concentrated. Column chromatography (silica, 10-20% EtOAc/hexanes) provided 744 mg (72%) of 4-(2-methoxycarbonyl-6-nitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester. TLC (silica, 20% EtOAc/hexanes): Rf=0.5. 1H NMR (400 MHz, CDCl3): 7.67 (dd, J=8.2, 1.4 Hz, 1H), 7.62 (dd, J=8.2, 1.4 Hz, 1H), 7.16 (t, J=8.2 Hz, 1H), 3.86 (s, 3H), 3.44-3.36 (m, 4H), 3.03-2.95 (m, 4H), 1.48 (s, 9H).

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux for 4 h
  3. customThe solvent was removed under reduced pressure
  4. customThe crude product was partitioned between EtOAc (100 mL) and 20 mL of H2O
  5. washThe organic layer was washed with H2O (2×20 mL)
  6. dry with materialdried over Na2SO4
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-782822216506472f82d3d997adc691f0
Source dataset
uspto-grants-2007_12
Patent number
US07309703B2

Reaction notes

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