Reaktion #828711

Reaktionsgleichung

HCl

Hydrogen

borane methyl sulfide

cyclohexene

→

title product

Ausbeute 75.0%

Dicyclohexylchloroborane

Ausbeute 75.0%

Lösungsmittel

ether

diethyl ether

diethyl ether

Reaktionsbedingungen

Aufarbeitung

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

Vorschrift

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).

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