反应 #5281

反应方程式

benzyl bromide

ethyl 2-cyanoethyl(diethoxymethyl)phosphinate

ammonium chloride

diisopropylamine

n-butyllithium

→

ethyl 2-benzyl-2-cyanoethyl(diethoxymethyl)phosphinate

溶剂

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

hexane

反应条件

后处理

1. 1
   workup.ADDITIONis introduced
2. 2
   workup.ADDITIONis added
3. 3
   萃取The aqueous layer is then extracted with 2×25 ml of diethyl ether
4. 4
   干燥dried over magnesium sulphate
5. 5
   其他The solvent is then evaporated under reduced pressure
6. 6
   其他the crude product chromatographed on silica gel

实验过程

To a solution of 0.97 g of diisopropylamine in 40 ml of tetrahydrofuran at -78° C. under an atmosphere of nitrogen are added 6.0 ml of a 1.6M solution of n-butyllithium in hexane. This solution is then stirred for a period of 10 minutes at this temperature, after which time a solution of 2.0 g of ethyl 2-cyanoethyl(diethoxymethyl)phosphinate in 10 ml of tetrahydrofuran is added. This mixture is then stirred for a period of 1 hour at -78° C. after which time a solution of 1.4 g of benzyl bromide in 10 ml of tetrahydrofuran is introduced. This mixture is then allowed to warm to room temperature when 40 ml of a saturated ammonium chloride solution is added. The aqueous layer is then extracted with 2×25 ml of diethyl ether and the organic extracts are combined and dried over magnesium sulphate. The solvent is then evaporated under reduced pressure and the crude product chromatographed on silica gel using ethyl acetate as an eluent to give ethyl 2-benzyl-2-cyanoethyl(diethoxymethyl)phosphinate as a viscous oil, 31P=+40.7 and +40.5 ppm (CDCl3).

来源