反応 #2028869

反応方程式

HCl

Ethyl difluoroacetate

sodium methoxide

methanol

4′-chloroacetophenone

→

yellow solid

収率 99.5%

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

収率 99.5%

溶媒

ether

diethyl ether

diethyl ether

反応条件

後処理

1. 1
   workup.ADDITIONadded to the reaction dropwise over 5 minutes
2. 2
   workup.ADDITIONwere added
3. 3
   その他The organic layer was collected
4. 4
   洗浄washed with brine (250 mL)
5. 5
   乾燥dried over MgSO4
6. 6
   ろ過filtered
7. 7
   濃縮concentrated in vacuo

実験手順

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.

出典