Reaktion #1447082

Reaktionsgleichung

acrolein

lithium diisopropylamide

ethyl [(1-methyl-3-trifluoromethyl-1H-pyrazole-4-carbonyl)amino]acetate

NH4Cl

→

Ethyl 3-hydroxy-2-[(1-methyl-3-trifluoromethyl-1H-pyrazole-4-carbonyl)amino]pent-4-enoate

Lösungsmittel

THF

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture was cooled to −78° C.
2. 2
   workup.ADDITIONwere added dropwise
3. 3
   workup.STIRRINGAfter 2 h of stirring at −78° C.
4. 4
   Temperaturwarmed to RT
5. 5
   SonstigeAfter separation of the phases
6. 6
   Sonstigethe organic phase was dried
7. 7
   Sonstigethe solvent was removed
8. 8
   SonstigeThe residue was purified chromatographically (SiO2, cyclohexane/ethyl acetate)
9. 9
   SonstigeThis gave 1.65 g (40% of theory) of the title compound as a colorless solid (about 1:1 diastereomer mixture) which was used without further purification

Vorschrift

At −50° C., 3.45 g (12.4 mmol) of ethyl [(1-methyl-3-trifluoromethyl-1H-pyrazole-4-carbonyl)amino]acetate dissolved in THF were added dropwise to 18.5 ml (37.0 mmol) of a 2M solution of lithium diisopropylamide in THF/heptanelethylbenzene. After 1.5 h of stirring at −50° C., the mixture was cooled to −78° C. and 0.83 g (14.8 mmol) of acrolein dissolved in THF were added dropwise. After 2 h of stirring at −78° C., the mixture was hydrolyzed with sat. NH4Cl solution and warmed to RT. After separation of the phases, the organic phase was dried and the solvent was removed. The residue was purified chromatographically (SiO2, cyclohexane/ethyl acetate). This gave 1.65 g (40% of theory) of the title compound as a colorless solid (about 1:1 diastereomer mixture) which was used without further purification.

Quelle