Hydrochloric Acid → HCID 19973073, Verbindung

To 40 ml of a solution of lithium diisopropylamide in dried diethyl ether prepared from 4.3 g of diisopropylamine and 26.0 ml of a 1.64N n-hexane solution of n-butyllithium was dropwise added 10 ml of a dried diethyl ether solution containing 5.1 g of ethyl 2-fluoropropionate at -70° to -60° C. The mixture was stirred at the same temperature for 15 minutes. Thereto was dropwise added 60 ml of a dried diethyl ether solution containing 6.2 g of 2-chloro-2',4'-difluoroacetophenone at -70° to -60° C. Then, the temperature of the mixture was elevated to 20° C. in 5 hours. The reaction mixture obtained was introduced into a mixed solvent consisting of 100 ml of ethyl acetate and 50 ml of water. The resulting solution was adjusted to pH 2.0 with 6N hydrochloric acid. The organic layer was separated, washed with a saturated aqueous sodium chloride solution, and then dried over anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure. The residue thus obtained was purified by a column chromatography (eluant: n-hexane/toluene=2/1) to obtain 3.9 g of oily ethyl 3-(2,4-difluorophenyl)-3,4-epoxy-2-fluoro-2methylbutyrate (a mixture of diastereomers).

1. waitThen, the temperature of the mixture was elevated to 20° C. in 5 hours
2. customThe reaction mixture obtained
3. additionwas introduced into a mixed solvent
4. customThe organic layer was separated
5. washwashed with a saturated aqueous sodium chloride solution
6. dry with materialdried over anhydrous magnesium sulfate
7. customThe solvent was removed by distillation under reduced pressure
8. customThe residue thus obtained
9. customwas purified by a column chromatography (eluant: n-hexane/toluene=2/1)

ORD-Eintrag

ord-c989f2be73fd4b24842f5b59afb81b4b

Quelldatensatz

uspto-grants-1997_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05605921