Benzil → 6-methyl-2,3-diphenylquinoxaline

HRID 478917Notes

Reaction equation

HRID 478917 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([CH3:8])=[CH:4][C:3]=1[NH2:9].[C:10]1([C:16]([C:18]([C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)=O)=O)[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1>C(O)(=O)C>[CH3:8][C:5]1[CH:4]=[C:3]2[C:2](=[CH:7][CH:6]=1)[N:1]=[C:18]([C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)[C:16]([C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1)=[N:9]2

Participants

4

Reactant 2

HCID 8651BenzilHCID 103323,4-Diaminotoluene

Product 1

HCID 15520156-methyl-2,3-diphenylquinoxaline

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

1,2-Diamino-4-methylbenzene (25.0 g, 0.20 mol) and benzil (43 g, 0.20 mol) were refluxed in ethanoic acid (250 ml) overnight. The solvent was evaporated in vacuo and the black residue recrystallised three times from ethanol to give pale brown crystals of 6-methyl-2,3-diphenylquinoxaline, 39.6 g, 65% (m.pt. 114.5-116° C. (lit.iv 115-116° C.)). 1H NMR (CDCl3, 300 MHz) δ 8.08 (d, J 8.4 Hz, 1H, Hs of quinoxaline), 7.97 (bs, 1H, Hs of quinoxaline), 7.60 (d of d, J 8.4 Hz, J 1.8 Hz, 1H, Hs of quinoxaline), 7.50-7.58 (m, 4H, phenyl rings), 7.30-7.38 (m, 6H, phenyl rings), 2.62 (s, 3H, Ch3).

Workup

  1. customThe solvent was evaporated in vacuo
  2. customthe black residue recrystallised three times from ethanol

Sources & evidence

ORD record
ord-2015a74147a94ad78b6ceb205882f9d5
Source dataset
uspto-grants-2003_11
Patent number
US06642332B1

Reaction notes

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