Reacción #828711

Ecuación de reacción

HCl

Hydrogen

borane methyl sulfide

cyclohexene

→

title product

Rendimiento 75.0%

Dicyclohexylchloroborane

Rendimiento 75.0%

Disolventes

ether

diethyl ether

diethyl ether

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroA 500-mL round-bottom flask capped with a rubber septum, a magnetic stirring bar, and a connecting tube
2. 2
   TemperaturaThe flask was cooled in an ice bath
3. 3
   OtroDicyclohexylborane precipitated as a white solid
4. 4
   OtroThe supernatant liquid was removed by a double-ended needle
5. 5
   Lavadothe solid was washed with ether
6. 6
   Otrothe liquid was removed
7. 7
   OtroA clear solution was obtained
8. 8
   workup.DISTILLATIONDistillation

Procedimiento

A 500-mL round-bottom flask capped with a rubber septum, a magnetic stirring bar, and a connecting tube attached to a mercury bubbler was charged with diethyl ether (150 mL) and cyclohexene (41 mL, 400 mmol). The flask was cooled in an ice bath, borane-methyl sulfide (BMS, 20 mL, 200 mmol) was added slowly, and stirring was continued for 3 h at 0° C. Dicyclohexylborane precipitated as a white solid. The supernatant liquid was removed by a double-ended needle, the solid was washed with ether, and the liquid was removed. Then the solid was suspended in 100 mL of diethyl ether, and anhydrous HCl in ether (66.7 mL of 3M solution, 200 mmol) was added slowly to the suspension at 0° C. Hydrogen is rapidly evolved and should be safely vented. A clear solution was obtained. The 11B NMR analysis of the resulting solution showed formation of Chx2BCl (δ 66 ppm in diethyl ether). Distillation provides the pure title product (δ 76 ppm in hexane), 31.6 g, 75% yield, bp 95°-96 ° C. (0.35 mm).

Fuente