Reaction #2146692

Reaction equation

4′-benzoyloxy-2-bromoacetophenone

2-amino-5-methoxypyridine

sodium hydrogencarbonate

→

2-(4′-benzoyloxyphenyl)-6-methoxyimidazo[1,2-a]pyridine

Yield 70.7%

Solvents

ethanol

Conditions

Workup

1. 1
   TemperatureThe resulting solution was refluxed for 2 hours
2. 2
   TemperatureAfter the reaction solution was cooled
3. 3
   OtherThe resulting reaction mixture
4. 4
   Temperaturewas further refluxed for 4 hours
5. 5
   OtherAfter the completion of the reaction
6. 6
   Concentrationthe solvent was concentrated under reduced pressure
7. 7
   workup.DISSOLUTIONThe resulting residue was dissolved in chloroform
8. 8
   Washwashed with water
9. 9
   DryingAfter the chloroform layer was dried over anhydrous sodium sulfate
10. 10
    workup.DISTILLATIONthe solvent was distilled off
11. 11
    OtherThe resulting crude product was purified by silica gel column chromatography (elution solvent: chloroform/ethyl acetate=20/1)

Procedure

13.33 g (corresponding to 43.68 mmol) of 4′-benzoyloxy-2-bromoacetophenone and 5.67 g (corresponding to 45.67 mmol) of 2-amino-5-methoxypyridine were dissolved in 481 mL of ethanol. The resulting solution was refluxed for 2 hours. After the reaction solution was cooled, 6.64 g (corresponding to 79.09 mmol) of sodium hydrogencarbonate was added thereto. The resulting reaction mixture was further refluxed for 4 hours. After the completion of the reaction, the solvent was concentrated under reduced pressure. The resulting residue was dissolved in chloroform and then washed with water. After the chloroform layer was dried over anhydrous sodium sulfate, the solvent was distilled off. The resulting crude product was purified by silica gel column chromatography (elution solvent: chloroform/ethyl acetate=20/1) to obtain 10.20 g (corresponding to 30.87 mmol) of 2-(4′-benzoyloxyphenyl)-6-methoxyimidazo[1,2-a]pyridine (FIG. 3, Step 5).

Source