O-Phenylenediamine → 3-(2-Thienyl)-1,2-dihydroquinoxalin-2-one

HRID 553451Notes

Reaction equation

HRID 553451 reaction equation
[C:1]1([NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH2:7].[S:9]1[CH:13]=[CH:12][CH:11]=[C:10]1[C:14](=O)[C:15](OCC)=[O:16]>CO>[S:9]1[CH:13]=[CH:12][CH:11]=[C:10]1[C:14]1[C:15](=[O:16])[NH:7][C:2]2[C:1]([N:8]=1)=[CH:6][CH:5]=[CH:4][CH:3]=2

Participants

4

Reactant 2

HCID 7243O-PhenylenediamineHCID 77693Ethyl 2-thiopheneglyoxylate

Product 1

HCID 7236983-(2-Thienyl)-1,2-dihydroquinoxalin-2-oneYield 70.1%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of o-phenylenediamine (2.16 g, 20 mmol) and ethyl thiophene-2-glyoxylate (3.68 g, 20 mmol.) in anhydrous methanol (60 mL) was stirred at room temperature for 12 hours under nitrogen atmosphere. The precipitate formed during this time was collected and washed with methanol to give a crude yellow solid, which was recrystallized from ethanol to give pure 3(2-thienyl)quinoxalin-2(1 H)-one (3.2 g, 70%). 1 H NMR (400 MHz, DMSO-d6) δ 12.7 (s, 1 H), 8.39 (d, J=4.4 Hz, 1 H), 7.83 (d, J=5.2 Hz, 1 H), 7.77 (d, J=8.0 Hz, 1H), 7.50 (t, J=7.6 Hz, 1H), 7.35˜7.29 (m, 1 H), 7.22 (t, J=4.8 Hz, 1 H).

Workup

  1. customThe precipitate formed during this time
  2. customwas collected
  3. washwashed with methanol
  4. customto give a crude yellow solid, which
  5. customwas recrystallized from ethanol

Sources & evidence

ORD record
ord-bf08d39f67eb41638511bdae3c1cb79a
Source dataset
uspto-grants-2011_11
Patent number
US08048862B2

Reaction notes

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