反应 #595300

反应方程式

hydrogen peroxide

Maleic anhydride

hydrogen peroxide

1-[3-bromo-1-(2-chlorophenyl)prop-1-en-2-yl]-2,4-difluorobenzene

→

2-(bromomethyl)-3-(2-chlorophenyl)-2-(2,4-difluorophenyl)oxirane

收率 40.0%

溶剂

acetic acid

反应条件

后处理

1. 1
   workup.STIRRINGthe reaction mixture was stirred at 20° C. for 66 h
2. 2
   其他was quenched by addition of sat. aq. sodium thiosulphate
3. 3
   萃取The mixture was extracted with dichloromethane
4. 4
   干燥the organic phase was dried over MgSO4
5. 5
   浓缩concentrated under reduced pressure
6. 6
   其他Purification of the residue on silica gel

实验过程

Maleic anhydride (2.05 g, 20.9 mmol) and then hydrogen peroxide (35% by weight strength solution, 2.04 g, 20.9 mmol) were added to a stirred solution of 1-[3-bromo-1-(2-chlorophenyl)prop-1-en-2-yl]-2,4-difluorobenzene (720 mg, 2.09 mmol) in acetic acid (20 ml). The reaction mixture was stirred at 40° C. for 24 h, more hydrogen peroxide (35% by weight strength solution, 2.04 g, 20.9 mmol) was then added and the reaction mixture was stirred at 20° C. for 66 h. Excess oxidizing agent was quenched by addition of sat. aq. sodium thiosulphate. The mixture was extracted with dichloromethane, and the organic phase was dried over MgSO4 and concentrated under reduced pressure. Purification of the residue on silica gel gave 2-(bromomethyl)-3-(2-chlorophenyl)-2-(2,4-difluorophenyl)oxirane as a 59/41 mixture of diastereoisomers [316 mg, colourless oil, yield 40%; GC/MS: m/z=279 ([M-Br]+); HPLC/MS: log P(HCOOH)=4.61 (major diastereoisomer), 5.00 (minor diastereoisomer)].

来源