HCID 54077828, compound → 6-bromo-3-methyl-3,4-dihydro-1H-quinoxalin-2-one

HRID 1007111Notes

Reaction equation

HRID 1007111 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]([N+:14]([O-])=O)=[C:6]([NH:8][C@H:9]([C:11](O)=[O:12])[CH3:10])[CH:7]=1>C(O)(=O)C.[Fe]>[Br:1][C:2]1[CH:7]=[C:6]2[C:5](=[CH:4][CH:3]=1)[NH:14][C:11](=[O:12])[CH:9]([CH3:10])[NH:8]2

Participants

4

Reactant 1

HCID 54077828HCID 54077828, compound

Product 1

HCID 117156816-bromo-3-methyl-3,4-dihydro-1H-quinoxalin-2-oneYield 51.3%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 176Acetic AcidSolvent

Conditions

Temperature
90 °C

Procedure

To a solution of N-(5-bromo-2-nitrophenyl)-alanine (22 g, 76 mmol) in acetic acid (300 ml) was added iron powder (10 g, 180 mmol), and the mixture was stirred for 2 hours at 90° C. The reaction mixture was cooled and filtered, and the acetic acid was evaporated. The remaining slurry was extracted with methylene chloride (3×200 ml). The combined extracts were combined, dried over magnesium sulfate, filtered, and evaporated to afford 6-bromo-3-methyl-3,4-dihydro-1H-quinoxalin-2-one (9.4 g, 51%). A sample was recrystallized from ethanol: m.p. 133-135° C. 1H-NMR (DMSO-d6) δ 1.23 (d, J=6.81 Hz, 3H), 3.80 (q, J=6.81 Hz, 1H), 6.27 (bs, 1H), 6.63 (d, J=8.35 Hz, 1H), 6.72 (dd, J=8.35, 1.76 Hz, 1H), 6.80 (d, J=1.76 Hz, 1H), 10.29 (s, 1H).

Workup

  1. temperatureThe reaction mixture was cooled
  2. filtrationfiltered
  3. customthe acetic acid was evaporated
  4. extractionThe remaining slurry was extracted with methylene chloride (3×200 ml)
  5. dry with materialdried over magnesium sulfate
  6. filtrationfiltered
  7. customevaporated

Sources & evidence

ORD record
ord-0fc573a39b3c4698989505b4fa2a3140
Source dataset
uspto-grants-2004_09
Patent number
US06794373B2

Reaction notes

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