Reacción #2028869

Ecuación de reacción

HCl

Ethyl difluoroacetate

sodium methoxide

methanol

4′-chloroacetophenone

→

yellow solid

Rendimiento 99.5%

4,4-difluoro-1-[4-(chloro)phenyl]-butane-1,3-dione

Rendimiento 99.5%

Disolventes

ether

diethyl ether

diethyl ether

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONadded to the reaction dropwise over 5 minutes
2. 2
   workup.ADDITIONwere added
3. 3
   OtroThe organic layer was collected
4. 4
   Lavadowashed with brine (250 mL)
5. 5
   Secadodried over MgSO4
6. 6
   Filtraciónfiltered
7. 7
   Concentraciónconcentrated in vacuo

Procedimiento

Ethyl difluoroacetate (24.82 g, 200 mmol) was placed in a 500 mL three-necked round bottom flash, and dissolved in diethyl ether (200 mL). To the stirred solution was added 25% sodium methoxide in methanol (48 mL, 210 mmol) via an addition funnel over a 2 minute period. Next, 4′-chloroacetophenone (25.94 g, 200 mmol) was dissolved in diethyl ether (50 mL), and added to the reaction dropwise over 5 minutes. After stirring overnight (18 hours), 1N HCl (250 mL) and ether (250 mL) were added. The organic layer was collected, washed with brine (250 mL), dried over MgSO4, filtered, and concentrated in vacuo to give 46.3 g of a yellow solid. The solid was recrystallized from methylene chloride and iso-octane to give 31.96 g (69%) of the dione: mp 65°-66.5° C.

Fuente