Реакция #595300

Уравнение реакции

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

Выход 40.0%

Растворители

acetic acid

Условия реакции

Обработка

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

Методика

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)].

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