Reacción #1447082

Ecuación de reacción

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

Disolventes

THF

THF

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturathe 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
   Temperaturawarmed to RT
5. 5
   OtroAfter separation of the phases
6. 6
   Otrothe organic phase was dried
7. 7
   Otrothe solvent was removed
8. 8
   OtroThe residue was purified chromatographically (SiO2, cyclohexane/ethyl acetate)
9. 9
   OtroThis 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

Procedimiento

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.

Fuente