Reaction #1960532

Reaction equation

2-bromo-4′-hydroxyacetophenone

2-amino-5-bromopyridine

→

6-bromo-2-(4′-hydroxyphenyl)imidazo[1,2-a]pyridine

Yield 83.2%

Solvents

acetonitrile

Conditions

Workup

1. 1
   OtherAfter the completion of the reaction
2. 2
   Temperaturethe reaction solution was cooled down to room temperature
3. 3
   Otherprecipitates
4. 4
   Filtrationwere filtered
5. 5
   Otherrecovered
6. 6
   WashThe precipitates were washed with acetonitrile
7. 7
   Otherdried under reduced pressure
8. 8
   workup.ADDITIONThen, about 25 mL of a saturated sodium hydrogencarbonate solution was added
9. 9
   Otherthe mixture was sonicated for 5 minutes
10. 10
    OtherPrecipitates
11. 11
    Filtrationwere filtered
12. 12
    Otherrecovered from the resulting mixture
13. 13
    Washsufficiently washed with water
14. 14
    Otherdried under reduced pressure

Procedure

2.15 g (corresponding to 10.0 mmol) of 2-bromo-4′-hydroxyacetophenone and 1.74 g (corresponding to 10.0 mmol) of 2-amino-5-bromopyridine were dissolved in 50 mL of acetonitrile. The resulting solution was refluxed in an oil bath at 105° C. for 6 hours. After the completion of the reaction, the reaction solution was cooled down to room temperature, and precipitates were filtered and recovered. The precipitates were washed with acetonitrile and dried under reduced pressure. The resulting crude crystals were suspended in a mixed solution of 20 mL of water and 20 mL of methanol. Then, about 25 mL of a saturated sodium hydrogencarbonate solution was added thereto, and the mixture was sonicated for 5 minutes using an ultrasonic washing machine. Precipitates were filtered and recovered from the resulting mixture, sufficiently washed with water, and dried under reduced pressure, to obtain 2.41 g (corresponding to 8.32 mmol) of 6-bromo-2-(4′-hydroxyphenyl)imidazo[1,2-a]pyridine (FIG. 1-2, Step 2).

Source