4-Methyl-2-oxovaleric acid → Ethyl 3-bromo-4-methyl-2-oxopentanoate

Temperature

20 °C

To a solution of 4-methyl-2-oxopentanoic acid (5 g) in acetic acid (40 ml) was added pyridine hydrobromide perbromide (12.3 g) and the mixture stirred at 20° C. for 18 hr, then the solvent was removed in vacuo. The residue was dissolved in DCM (100 ml) and washed with water (100 ml), separated by hydrophobic frit and evaporated. The residue was taken up in ethanol (100 ml) and treated with concentrated sulphuric acid (1 ml) and heated at reflux for 18 h, then concentrated in vacuo to approx 30 ml. The mixture was diluted with water (250 ml) and extracted with diethyl ether (100 ml), dried over sodium sulphate and evaporated to give the title compound as a pale yellow oil (5.3 g).

1. customthe solvent was removed in vacuo
2. dissolutionThe residue was dissolved in DCM (100 ml)
3. washwashed with water (100 ml)
4. customseparated by hydrophobic frit
5. customevaporated
6. additiontreated with concentrated sulphuric acid (1 ml)
7. temperatureheated
8. temperatureat reflux for 18 h
9. concentrationconcentrated in vacuo to approx 30 ml
10. additionThe mixture was diluted with water (250 ml)
11. extractionextracted with diethyl ether (100 ml)
12. dry with materialdried over sodium sulphate
13. customevaporated

ORD record

ord-555e5145f1344fa6a5e3a477d46929df

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08658635B2