Reaktion #67882

Reaktionsgleichung

hydrochloric acid ethyl acetate

triisopropyl borate

chloroiodomethane

n-butyllithium

pinacol

→

compound

Ausbeute 81.0%

2-(chloromethyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Ausbeute 81.0%

Lösungsmittel

n-hexane

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added dropwise at −78° C. (an outer temperature) for 20 min
2. 2
   workup.ADDITIONwas added dropwise
3. 3
   workup.STIRRINGthe reaction mixture was stirred at room temperature for 40 min
4. 4
   SonstigeThe solvents were evaporated under reduced pressure
5. 5
   workup.DISTILLATIONthe obtained residue was distilled under reduced pressure (63-70° C., 11 mmHg)

Vorschrift

To the mixture of triisopropyl borate (15 ml, 65 mmol), chloroiodomethane (13 g, 72 mmol), and tetrahydrofuran (78 ml), n-butyllithium (a 1.6 M n-hexane solution, 41 ml, 65 mmol) was added dropwise at −78° C. (an outer temperature) for 20 min, and then the obtained mixture was stirred at room temperature for 2.5 hours. The reaction mixture was cooled to 0° C. (an outer temperature), and a 4 N hydrochloric acid-ethyl acetate solution was added dropwise thereto at the same temperature until the reaction mixture became neutral. At the same temperature, pinacol (7.7 g, 65 mmol) was added to the reaction mixture, and then the reaction mixture was stirred at room temperature for 40 min. The solvents were evaporated under reduced pressure, and then the obtained residue was distilled under reduced pressure (63-70° C., 11 mmHg), thereby obtaining the entitled compound (9.2 g, 52 mmol, 81%).

Quelle