반응 #51994

반응 방정식

tert-Butyl 2-(4-bromophenyl)-2-hydroxyethyl(methyl)carbamate

DMF

MeMgBr

ammonium chloride

tetramethyl ethylenediamine

nBuLi

→

product

수율 68.6%

tert-Butyl 2-(4-formylphenyl)-2-hydroxyethyl(methyl)carbamate

수율 68.6%

용매

THF

ether

hexane

반응 조건

후처리

1. 1
   온도The stirred mixture was cooled in an ice bath
2. 2
   workup.ADDITIONwas added
3. 3
   workup.ADDITIONwas added
4. 4
   기타Most of the organic solvent was evaporated
5. 5
   추출the residual mass was extracted with ethyl acetate (3×500 ml)
6. 6
   세척washed with water (300 ml) and brine (100 ml)
7. 7
   건조then dried over magnesium sulfate
8. 8
   여과Filtration and evaporation
9. 9
   기타gave a viscous oil that
10. 10
    기타was chromatographed over silica gel (500 g)
11. 11
    세척Elution with 25-40% ethyl acetate-hexane

실험 절차

tert-Butyl 2-(4-bromophenyl)-2-hydroxyethyl(methyl)carbamate (36.7 g, 111.2 mmol) was dissolved in dry THF (600 ml) under N2 and tetramethyl ethylenediamine (42.2 ml, 32.5 g, 280.1 mmol) was added. The stirred mixture was cooled in an ice bath and a 3M ether solution of MeMgBr (46.4 ml, 139.3 mmol). After stirring for 1 hr a 1.6M hexane solution of nBuLi (150 ml, 240 mmol) was added and stirred for an additional 1 hr at which time dry DMF (50 ml, 47.2 g, 647 mmol) was added. After 1 hr a satd. solution (100 ml) of ammonium chloride was added. Most of the organic solvent was evaporated and the residual mass was extracted with ethyl acetate (3×500 ml), washed with water (300 ml) and brine (100 ml) then dried over magnesium sulfate. Filtration and evaporation gave a viscous oil that was chromatographed over silica gel (500 g). Elution with 25-40% ethyl acetate-hexane gave the product as a pale yellow gum (21.3 g) which very slowly crystallized to a yellow solid.

출처