反应详情

Diisopropylamine (5.04 ml, 1.5 eq) in anhydrous THF at −78° C. and n-butyllithium in hexane were mixed and dissolved into 2.5 M of solution (10.55 ml, 1.1 eq). The 2-(4-bromophenyl)-methylbutyric acid methyl ester (6.5 g, 1 eq) in the Step 2 was added into the solution and stirred. After 30 minutes, 1,3-dibromopropane (7.31 ml, 3 eq) was dissolved in anhydrous THF. The mixture was dropped into the solution and stirred at room temperature overnight. When the reaction was completed, the compound was extracted with diethylether and water, washed with 1N HCl and saturated NaHCO3. The organic layer was dried with anhydrous magnesium sulfate and the solvent was removed at low pressures. Subsequently, the target compound 5-bromo-2-(4-bromophenyl)-2-isopropylpentanoic methyl ester was obtained by separation and purification of the mixture using a column chromatography (ethyl acetate:n-hexane=1:100) (5.98 g, 44%).

1. additionThe mixture was dropped into the solution
2. stirringstirred at room temperature overnight
3. extractionthe compound was extracted with diethylether and water
4. washwashed with 1N HCl and saturated NaHCO3
5. dry with materialThe organic layer was dried with anhydrous magnesium sulfate
6. customthe solvent was removed at low pressures