Ethanol → Ethyl 2-oxovalerate

Temperatur

80 °C

0.1 mol of 2,2-(dimethylthio)pentanoic acid (11) (19.4 g) was dissolved in 150 ml of toluene and admixed with 2.0 eq of H2O (3.6 ml) and a spatula-tip of p-toluenesulfonic acid monohydrate. Subsequently, the mixture was heated to boiling point and a nitrogen stream was passed through the solution via a frit. After 3 h under reflux, the reaction mixture was cooled to 80° C. and admixed with 200 ml of ethanol and a further spatula-tip of p-toluenesulfonic acid monohydrate. After a further 3 h under reflux, the mixture was cooled to 20° C., 200 ml of water were added and the mixture was extracted three times with 100 ml each time of diethyl ether. The combined ether phases were subsequently washed to neutrality with a dilute sodium hydrogencarbonate solution and dried over magnesium sulfate. After filtration, all of the solvent was drawn off with a rotary evaporator. The ethyl 2-oxovalerate (12) (10.2 g, yield=71%) was obtained as a pale yellowish oil.

1. temperatureSubsequently, the mixture was heated
2. temperatureAfter 3 h under reflux
3. temperatureAfter a further 3 h under reflux
4. temperaturethe mixture was cooled to 20° C.
5. extractionthe mixture was extracted three times with 100 ml each time of diethyl ether
6. washThe combined ether phases were subsequently washed to neutrality with a dilute sodium hydrogencarbonate solution
7. dry with materialdried over magnesium sulfate
8. filtrationAfter filtration
9. customall of the solvent was drawn off with a rotary evaporator

ORD-Eintrag

ord-81de71cd93d54403bbaf1150c150dc65

Quelldatensatz

uspto-grants-2012_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08299293B2