反应详情

2,4-dimethyl-3-pentanone (330 g, 2.89M) in chloroform (800 ml) was cooled in an ice water bath to 10° C. and bromine (462 g, 2.89M) was added slowly over 3 hours. After the addition, a slow stream of nitrogen was introduced to the mixture and HBr gas was slowly evolved from the flask. The nitrogen was left bubbling over a weekend to remove all of the HBr produced and then sodium carbonate (5 g) was added. The reaction mixture was then filtered through Celite and the chloroform removed using a rotary evaporator. Distillation of the crude product using a 1′ (2.54 cm) vigreux gave essentially pure 2-bromo-2,4-dimethyl-3-pentanone (478 g, 2.47M) b.pt. 50-52° C./10 mb (1000 Nm−2).

1. additionAfter the addition
2. waitThe nitrogen was left
3. custombubbling over a weekend
4. customto remove all of the HBr
5. customproduced
6. filtrationThe reaction mixture was then filtered through Celite
7. customthe chloroform removed
8. customa rotary evaporator
9. distillationDistillation of the crude product