反应详情

A quantity (3.04 g., 0.01 mole) of 3,4,5-tribromopyrazole was dissolved in 70 ml. acetone and 2.76 g. (0.02 mole) solid anhydrous potassium carbonate was added. The mixture was heated at the reflux temperature with stirring for 10 minutes and after cooling, 1.85 g. (0.011 mole) of 2-bromoethyl acetate was added. This reaction mixture was heated at the reflux temperature for 12 hrs. cooled, filtered, and the acetone removed under reduced pressure. The resultant oil consisted of a mixture of the desired acetate and the corresponding alcohol. The mixture was dissolved in pyridine (15 ml.) and treated with acetic anhydride (3.06 g., 0.03 mole) at 0° C. This reaction mixture was kept at about 25° C. overnight, and then poured into 200 ml. of ice water. The precipitate that formed was collected on a filter, and washed with water. After drying and recrystallizing from hexane there was obtained 3,4,5-tribromopyrazole-1-ethanol acetate (ester) having a melting point at 64° to 67° C.

1. temperatureThe mixture was heated at the reflux temperature
2. temperatureafter cooling
3. temperatureThis reaction mixture was heated at the reflux temperature for 12 hrs
4. temperaturecooled
5. filtrationfiltered
6. customthe acetone removed under reduced pressure
7. additionThe resultant oil consisted of a mixture of the desired acetate
8. dissolutionThe mixture was dissolved in pyridine (15 ml.)
9. waitThis reaction mixture was kept at about 25° C. overnight
10. additionpoured into 200 ml
11. customThe precipitate that formed
12. customwas collected on a filter
13. washwashed with water
14. customAfter drying
15. customrecrystallizing from hexane