Réaction #2146693

Équation de réaction

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

boron tribromide

methanol

→

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

Rendement 89.5%

Solvants

dichloromethane

Conditions de réaction

Traitement

1. 1
   Autreto remove moisture
2. 2
   workup.DISSOLUTIONwas dissolved in 245 mL of chloroform
3. 3
   TempératureAfter the temperature of the resulting solution was raised to room temperature
4. 4
   AutreAfter the completion of the reaction
5. 5
   Températurethe reaction solution was cooled with ice
6. 6
   workup.STIRRINGfurther stirred at room temperature for 3 hours
7. 7
   ConcentrationThe reaction mixture was then concentrated under reduced pressure
8. 8
   Autreto obtain slurry
9. 9
   Autreprecipitates
10. 10
    Filtrationwere filtered
11. 11
    Autrerecovered
12. 12
    AutreThe precipitates recovered
13. 13
    Lavagewere washed with chloroform
14. 14
    Autredried under reduced pressure

Mode opératoire

4.90 g (corresponding to 14.83 mmol) of 2-(4′-benzoyloxyphenyl)-6-methoxyimidazo[1,2-a]pyridine that was sufficiently dried to remove moisture was dissolved in 245 mL of chloroform and cooled down to −15° C. To this solution, a solution of 12.62 mL (corresponding to 133.48 mmol) of boron tribromide in 134 mL of dichloromethane was added dropwise. After the temperature of the resulting solution was raised to room temperature, the solution was stirred for 17 hours. After the completion of the reaction, the reaction solution was cooled with ice and supplemented with 668 mL of methanol, and further stirred at room temperature for 3 hours. The reaction mixture was then concentrated under reduced pressure. The resulting crude product was supplemented with 290 mL of chloroform and 29 mL of methanol to obtain slurry, and then precipitates were filtered and recovered. The precipitates recovered were washed with chloroform and then dried under reduced pressure, to obtain 3.00 g (corresponding to 13.28 mmol) of 2-(4′-hydroxyphenyl)-6-hydroxyimidazo[1,2-a]pyridine (FIG. 3, Step 6).

Source