Water → 5-bromo-7-nitro-N-ethoxalylindoline

HRID 52461Notes

Reaction equation

HRID 52461 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[N:7]([C:11]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[O:12])[CH2:6][CH2:5]2.[N+:18]([O-])([O:20]C(C)C)=[O:19].O>S(=O)(=O)(O)O>[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[C:9]([N+:18]([O-:20])=[O:19])[CH:10]=1)[N:7]([C:11]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[O:12])[CH2:6][CH2:5]2

Participants

5

Reactant 3

HCID 962WaterHCID 15575Isopropyl nitrateHCID 100403095-bromo-N-ethoxalylindoline

Product 1

HCID 100202975-bromo-7-nitro-N-ethoxalylindolineYield 83.6%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 5-bromo-N-ethoxalylindoline (5.23 g, 17.5 mmol) in concentrated sulfuric acid was added slowly isopropyl nitrate (1.87 mL, 18.5 mmol) at 0° C. The mixture was stirred for 1 h at 0° C. and poured into a mixture of water and crashed ice. The mixture was extracted with ethyl acetate and the organic layer was washed with brine, dried over magnesium sulfate, and concentrated. The crude residue was purified by silica gel column chromatography to give 5.02 g of 5-bromo-7-nitro-N-ethoxalylindoline (83%): 1H NMR (270 MHz, CDCl3) δ7.91 (d, 1H, J=1 Hz), 7.62 (d, 1H, J=1 Hz), 4.39 (t, 2H, J=8 Hz), 4.38 (q, 2H, J=7 Hz), 3.22 (t, 2H, J=8 Hz), 1.39 (t, 3H, J=7 Hz).

Workup

  1. extractionThe mixture was extracted with ethyl acetate
  2. washthe organic layer was washed with brine
  3. dry with materialdried over magnesium sulfate
  4. concentrationconcentrated
  5. customThe crude residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-97088ed0433946a6a665735f78e31bc4
Source dataset
uspto-grants-1997_04
Patent number
US05616586

Reaction notes

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