Acetic Acid → 8-Bromo-5,6-dihydro-1H-pyrrolo[1,2,3-de]quinoxaline-2,3-dione

HRID 52462

Reaction equation

HRID 52462 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[C:9]([N+:11]([O-])=O)[CH:10]=1)[N:7]([C:14]([C:16]([O:18]CC)=O)=[O:15])[CH2:6][CH2:5]2.O.C(O)(=O)C>C1COCC1.[Cl-].[Cl-].[Cl-].[Ti+3]>[Br:1][C:2]1[CH:3]=[C:4]2[CH2:5][CH2:6][N:7]3[C:14](=[O:15])[C:16](=[O:18])[NH:11][C:9]([CH:10]=1)=[C:8]23

Participants

6

Reactant 3

HCID 176Acetic AcidHCID 962WaterHCID 100202975-bromo-7-nitro-N-ethoxalylindoline

Product 1

HCID 117777348-Bromo-5,6-dihydro-1H-pyrrolo[1,2,3-de]quinoxaline-2,3-dioneYield 50%

Reagents, catalysts & solvents 2

HCID 10313229titanium(III) trichlorideCatalystHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 5-bromo-7-nitro-N-ethoxalylindoline (2.0 g, 5.83 mmol) in a mixture of THF (50 mL), water (10 mL), and acetic acid (10 mL) was added aqueous 20% titanium trichloride (31 mL, 40.8 mmol) and the mixture was stirred for 4 h at room temperature. The precipitates formed were collected by filtration, washed with diluted aqueous hydrochloric acid and then distilled water, and dried in vacuo to give 772 mg of the title compound (50%): mp>300° C.; 1H NMR (270 MHz, DMSO-d6) δ11.91 (bs, 1H), 7.21 (d, 1H, J=1 Hz), 7.02 (d, 1H, J=1 Hz), 4.22 (t, 2H, J=7 Hz), 3.32 (t, 2H, J=7 Hz).

Workup

  1. customThe precipitates formed
  2. filtrationwere collected by filtration
  3. washwashed with diluted aqueous hydrochloric acid
  4. dry with materialdistilled water, and dried in vacuo

Sources & evidence

ORD record
ord-8bb1305d46414b1fb4b3af0acb2da657
Source dataset
uspto-grants-1997_04
Patent number
US05616586

Linked notes

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