Hydrochloric Acid → Ethyl 6-methyl-2,3,4,5-tetrafluorobenzoylacetate

Temperatur

-5 °C

A solution of 10.1 g (76.5 mmol) of malonic acid monoethylester, bipyridyl (catalytic), and 200 ml of dry THF was cooled to -35° C. under argon, treated with 52 ml of 1.5M n-butyllithium (78 mmol), and warmed to -5° C. To this mixture was added 52 ml of 1.5M n-butyllithium (78 mmol) until a pale pink color persisted for 10 minutes. The suspension was cooled to -78° C. and was treated with a solution of 8.8 g (38.8 mmol) of 2,3,4,5-tetrafluoro-6-methylbenzoyl chloride in 100 ml of dry THF. The reaction mixture was stirred at -78° C. for 45 minutes, then warmed to -35° C. and poured into a mixture of ice and 1N hydrochloric acid (77 ml). The organic layer was washed with 5% sodium bicarbonate solution, 3M hydrochloric acid, and water and dried over magnesium sulfate. Concentration gave an orange oil which was chromatographed on silica gel (E. Merck 230-400 Mesh), eluting with 80:20 chloroform:ethyl acetate, to give 8.2 g of the title compound.

1. temperatureThe suspension was cooled to -78° C.
2. temperaturewarmed to -35° C.
3. washThe organic layer was washed with 5% sodium bicarbonate solution, 3M hydrochloric acid, and water
4. dry with materialdried over magnesium sulfate
5. concentrationConcentration
6. customgave an orange oil which
7. customwas chromatographed on silica gel (E. Merck 230-400 Mesh)
8. washeluting with 80:20 chloroform

ORD-Eintrag

ord-c873e5700fbf4b78bd0db59754c4b10a

Quelldatensatz

uspto-grants-1990_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04920120