Reaction #2146706

Reaction equation

sodium hydrogencarbonate

2-bromo-4′-hydroxyacetophenone

2-amino-5-methoxypyridine

water

→

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

Yield 81.6%

Solvents

acetonitrile

methanol

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
   OtherThe recovered precipitates
7. 7
   Washwere washed with acetonitrile
8. 8
   Otherdried under reduced pressure
9. 9
   Otherto obtain crude crystals
10. 10
    Othersonicated for 5 minutes by an ultrasonic washing machine
11. 11
    FiltrationThe precipitates were filtered
12. 12
    Otherrecovered from the resulting mixture
13. 13
    Washwashed with water
14. 14
    Otherdried under reduced pressure

Procedure

2.15 g (corresponding to 10.0 mmol) of 2-bromo-4′-hydroxyacetophenone and 1.25 g (corresponding to 10.0 mmol) of 2-amino-5-methoxypyridine were dissolved in 50 mL of acetonitrile. The resulting solution was refluxed in an oil bath at 90° C. for 3.5 hours. After the completion of the reaction, the reaction solution was cooled down to room temperature, and precipitates were filtered and recovered. The recovered precipitates were washed with acetonitrile, and dried under reduced pressure to obtain crude crystals. The resulting crude crystals were suspended in a mixed solution of 40 mL of water and 40 mL of methanol. The suspension was supplemented with about 20 mL of a saturated sodium hydrogencarbonate solution, and sonicated for 5 minutes by an ultrasonic washing machine. The precipitates were filtered and recovered from the resulting mixture, washed with water, and dried under reduced pressure, to obtain 1.96 g (corresponding to 8.16 mmol) of 2-(4′-hydroxyphenyl)-6-methoxyimidazo[1,2-a]pyridine (FIG. 1, Step 5).

Source