Pyridine → 1-Cyclohexene-1-carboxylic acid, 4-methyl-6-oxo-, ethyl ester

Temperatur

0 °C

A suspension of phenylselenium chloride (27.29 g) in dichloromethane (250 mL) was stirred at 0° C. and treated dropwise with pyridine (11.81 g). The resulting mixture was stirred for 30 min, and then treated with a solution of racemic ethyl 4-methyl-2-oxocyclohexanecarboxylate (25 g) in dichloromethane (20 mL) in one portion. The color changed from brown to yellow, and the mixture was stirred at 0° C. for 15 min. After this time, the mixture was washed twice with 1 M aqueous HCl. The organic layer was cooled to 0° C. and then treated with 30% aqueous hydrogen peroxide (10.5 mL). After stirring for 10 min, an additional 30% aqueous hydrogen peroxide (10.5 mL) was added, followed by another an additional 30% aqueous hydrogen peroxide (10.5 mL) after 20 min. The resulting solution was stirred for 15 min and then treated with water (100 mL). The aqueous and organic layers were separated and the aqueous layer was extracted twice more with dichloromethane. The combined organic layers were washed with saturated aqueous sodium bicarbonate, dried over magnesium sulfate and concentrated under vacuum to provide racemic ethyl 4-methyl-6-oxocyclohex-1-enecarboxylate (26 g).

1. stirringThe resulting mixture was stirred for 30 min
2. stirringwas stirred at 0° C. for 15 min
3. washAfter this time, the mixture was washed twice with 1 M aqueous HCl
4. temperatureThe organic layer was cooled to 0° C.
5. additiontreated with 30% aqueous hydrogen peroxide (10.5 mL)
6. stirringAfter stirring for 10 min
7. additionan additional 30% aqueous hydrogen peroxide (10.5 mL) was added
8. customafter 20 min
9. stirringThe resulting solution was stirred for 15 min
10. additiontreated with water (100 mL)
11. customThe aqueous and organic layers were separated
12. extractionthe aqueous layer was extracted twice more with dichloromethane
13. washThe combined organic layers were washed with saturated aqueous sodium bicarbonate
14. dry with materialdried over magnesium sulfate
15. concentrationconcentrated under vacuum

ORD-Eintrag

ord-792713bb7f5d47cd8cef49ecbef26e0e

Quelldatensatz

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08507559B2