반응 #573544

반응 방정식

triisopropyl borate

1-bromo-3,4-difluorobenzene

magnesium

sulphuric acid

→

3,4-difluorophenylboric acid

용매

tetrahydrofuran

tetrahydrofuran

반응 조건

후처리

1. 1
   온도warmed to 14°-20° C.
2. 2
   workup.WAITleft
3. 3
   workup.WAITto stand overnight
4. 4
   여과the separated salt is filtered off
5. 5
   기타The aqueous phase of the filtrate is separated
6. 6
   추출extracted with diethyl ether
7. 7
   세척washed with sodium chloride solution
8. 8
   건조dried over sodium sulphate
9. 9
   기타evaporated

실험 절차

A Grignard reagent solution prepared from 46.8 g of 1-bromo-3,4-difluorobenzene and 6 g of magnesium in 150 ml of tetrahydrofuran is added dropwise at -65° C. under nitrogen to a solution of 72.8 ml of triisopropyl borate in 200 ml of tetrahydrofuran. The mixture is stirred at -65° C. for 1 hour, warmed to 14°-20° C., treated dropwise with 100 ml of 10 percent (v/v) sulphuric acid, left to stand overnight and the separated salt is filtered off. The aqueous phase of the filtrate is separated and extracted with diethyl ether. The organic phases are combined, washed with sodium chloride solution, dried over sodium sulphate and evaporated. After boiling with hexane the residue gives 22.1 g of colourless 3,4-difluorophenylboric acid m.p. 275°-277.5° C. (sublimed).

출처