Ethanol → 2-phenylimidazo[1,2-a]pyridine

HRID 1446437Notes

Reaction equation

HRID 1446437 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][N:3]=1.Br[CH2:9][C:10]([C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=O.C(=O)([O-])O.[Na+].C(O)C>CCCCCC.C(Cl)Cl>[C:12]1([C:10]2[N:1]=[C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][N:3]3[CH:9]=2)[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1

Participants

6

Reactant 4

HCID 702EthanolHCID 6259Phenacyl bromideHCID 104392-AminopyridineHCID 516892Sodium Bicarbonate

Product 1

HCID 2011362-phenylimidazo[1,2-a]pyridineYield 90%

Reagents, catalysts & solvents 1

HCID 21226440Methylenechloride HexaneSolvent

Procedure

Placing 2-aminopyridine in an amount of 3.5 g (36 mmol), α-bromoacetophenone in an amount of 7.2 g (36 mmol) and sodium hydrogen carbonate in an amount of 3.6 g (43 mmol) into a flask, the resultant mixture reacted among 120 milliliter of ethanol for 4 hours at the room temperature and subsequently for 2 hours under refluxing. Separating insoluble by filtration, the resultant filtrate was concentrated. Extracting with the use of methylene chloride in an amount of 150 milliliter, the resultant extract was washed three times using 200 milliliter of water. After drying an organic layer with the use of magnesium sulfide and removing the solvent, brown crystals were obtained. Refining the crystals by means of silicagel column (hexane/methylene chloride), 6.3 g of 2-phenylimidazo[1,2-a]pyridine Intermediate 1-1b as white crystals was obtained (yield: 90%). The white crystals were confirmed as the aimed compound from 1H-NMR spectrum. The measurement result is shown as follows:

Workup

  1. temperatureunder refluxing
  2. filtrationSeparating insoluble by filtration
  3. concentrationthe resultant filtrate was concentrated
  4. extractionExtracting with the use of methylene chloride in an amount of 150 milliliter
  5. extractionthe resultant extract
  6. washwas washed three times
  7. dry with materialAfter drying an organic layer with the use of magnesium sulfide
  8. customremoving the solvent
  9. custombrown crystals were obtained

Sources & evidence

ORD record
ord-c49b04f548184d0095c090edd4d43043
Source dataset
uspto-grants-2010_02
Patent number
US07667228B2

Reaction notes

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