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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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).

Herkunft & Nachweise