反应 #2028869

反应方程式

HCl

Ethyl difluoroacetate

sodium methoxide

methanol

4′-chloroacetophenone

→

yellow solid

收率 99.5%

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

收率 99.5%

溶剂

ether

diethyl ether

diethyl ether

反应条件

后处理

1. 1
   workup.ADDITIONadded to the reaction dropwise over 5 minutes
2. 2
   workup.ADDITIONwere added
3. 3
   其他The organic layer was collected
4. 4
   洗涤washed with brine (250 mL)
5. 5
   干燥dried over MgSO4
6. 6
   过滤filtered
7. 7
   浓缩concentrated in vacuo

实验过程

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.

来源