Ethyl Acetoacetate → Ethyl 2-bromo-3-oxobutanoate

Temperature

0 °C

3-Oxobutanoic acid ethyl ester (1.26 mL, 10.0 mmol) was added dropwise to a suspension of N-bromosuccinimide (1.78 g, 10.0 mmol) and p-toluenesulfonic acid (10.0 mg, 0.0581 mmol) in methylene chloride (30.0 mL) at 0° C., and the resultant reaction mixture was stirred at 0° C. for 3 h, then warmed to RT and stirred at that temperature for 1 h. The reaction mixture was concentrated in vacuo and the resultant oily solid was treated with hexanes and the resultant suspension was filtered. The solid was washed with additional hexanes and the filtrate was concentrated in vacuo to give a crude oil. Purification by flash column chromatography (100% hexanes to 30% Et2O/hexanes) gave the desired product (1.20 g, 57%) as an oil.

1. customthe resultant reaction mixture
2. temperaturewarmed to RT
3. stirringstirred at that temperature for 1 h
4. concentrationThe reaction mixture was concentrated in vacuo
5. additionthe resultant oily solid was treated with hexanes
6. filtrationthe resultant suspension was filtered
7. washThe solid was washed with additional hexanes
8. concentrationthe filtrate was concentrated in vacuo
9. customto give a crude oil
10. customPurification by flash column chromatography (100% hexanes to 30% Et2O/hexanes)

ORD record

ord-0791d94e493a4beca0436df60fe04eb6

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09399640B2