Reacción #5281

Ecuación de reacción

benzyl bromide

ethyl 2-cyanoethyl(diethoxymethyl)phosphinate

ammonium chloride

diisopropylamine

n-butyllithium

→

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

Disolventes

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

hexane

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONis introduced
2. 2
   workup.ADDITIONis added
3. 3
   ExtracciónThe aqueous layer is then extracted with 2×25 ml of diethyl ether
4. 4
   Secadodried over magnesium sulphate
5. 5
   OtroThe solvent is then evaporated under reduced pressure
6. 6
   Otrothe crude product chromatographed on silica gel

Procedimiento

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).

Fuente