Nitrogen → Ethyl 5-bromo-4-oxopentanoate

Bromine (22 g, 7.2 mL, 138.8 mmol) was added to a solution of ethyllevulinate (20 g, 138.8 mmol) in 250 mL EtOH at room temperature under a flow of N2 for a period of 0.5 h. After the addition was complete, the reaction mixture was stirred at room temperature for another 0.5 h, and then refluxed for 1.5 h. The reaction mixture was cooled to room temperature and concentrated in vacuo. The residue was taken into ether, washed with saturated aqueous NaHCO3 (3×50 mL), water, brine, dried (MgSO4) and concentrated to give 20.3 g of K-13 as a dark brown oil. This was used without purification for next step. 1H NMR.

1. additionAfter the addition
2. temperaturerefluxed for 1.5 h
3. temperatureThe reaction mixture was cooled to room temperature
4. concentrationconcentrated in vacuo
5. washwashed with saturated aqueous NaHCO3 (3×50 mL), water, brine
6. dry with materialdried (MgSO4)
7. concentrationconcentrated
8. customto give 20.3 g of K-13 as a dark brown oil
9. customThis was used without purification for next step

ORD record

ord-355d4b33474e4a43ad5a530109d6c2ac

Source dataset

uspto-grants-2010_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07714017B2