반응 #595300

반응 방정식

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

수율 40.0%

용매

acetic acid

반응 조건

후처리

1. 1
   workup.STIRRINGthe reaction mixture was stirred at 20° C. for 66 h
2. 2
   기타was quenched by addition of sat. aq. sodium thiosulphate
3. 3
   추출The mixture was extracted with dichloromethane
4. 4
   건조the organic phase was dried over MgSO4
5. 5
   농축concentrated under reduced pressure
6. 6
   기타Purification of the residue on silica gel

실험 절차

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)].

출처