Sodium Carbonate → 4-Chloro-7,8-dimethyl-imidazo[1,2-a]quinoxaline

HRID 1025479Notes

Reaction equation

HRID 1025479 reaction equation
[Cl:1][C:2]1[C:3]([NH2:14])=[N:4][C:5]2[C:10]([N:11]=1)=[CH:9][C:8]([CH3:12])=[C:7]([CH3:13])[CH:6]=2.[CH2:15](OC(OCC)CBr)[CH3:16].CC1C=CC(S([O-])(=O)=O)=CC=1.C1C=C[NH+]=CC=1.C(=O)([O-])[O-].[Na+].[Na+]>O.C1COCC1>[Cl:1][C:2]1[C:3]2[N:4]([CH:15]=[CH:16][N:14]=2)[C:5]2[C:10]([N:11]=1)=[CH:9][C:8]([CH3:12])=[C:7]([CH3:13])[CH:6]=2

Participants

6

Reactant 4

HCID 10340Sodium CarbonateHCID 74852Ethane, 2-bromo-1,1-diethoxy-HCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)HCID 856592133-Chloro-6,7-dimethyl-quinoxalin-2-ylamine

Product 1

HCID 866653244-Chloro-7,8-dimethyl-imidazo[1,2-a]quinoxalineYield 67.4%

Reagents, catalysts & solvents 1

HCID 21881883Oxolane--water (1/1)Solvent

Procedure

To a stirred suspension of 3-chloro-6,7-dimethyl-quinoxalin-2-ylamine (30.9 g, 0.16 mol) in water/THF 1:1 (540 mL) at room temperature was added bromoacetaldehyde diethyl acetal (94.6 g, 0.48 mol) and 5 g of PPTS in one portion. After stirring at room temperature for 1 h, the mixture was heated to reflux for 3 h under stirring and then stirred for an additional 15 h at room temperature. The pH value of the mixture was adjusted to pH 8 by addition of solid sodium carbonate. The precipitate formed was filtered off to give 25 g of the title compound. 1H-NMR (300 MHz, d6-DMSO): δ=8.85 (1H, s), 8.19 (1H, s), 7.73 (1H, bs), 7.80 (1H, bs), 3.60 (6H, s) ppm.

Workup

  1. temperaturethe mixture was heated
  2. temperatureto reflux for 3 h
  3. stirringunder stirring
  4. stirringstirred for an additional 15 h at room temperature
  5. customThe precipitate formed
  6. filtrationwas filtered off

Sources & evidence

ORD record
ord-27ad3a4c5ccd4239b9cd8f6df08ecdf8
Source dataset
uspto-grants-2014_05
Patent number
US08729082B2

Reaction notes

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