Reaktion #56928

Reaktionsgleichung

hydrochloric acid

sodium chloride

4-chloro-1-ethyl-2-iodo-benzene

isopropyl magnesium chloride

trimethyl borate

→

5-chloro-2-ethyl-phenyl boronic acid

Ausbeute 52.0%

Lösungsmittel

ethyl acetate

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe mixture was stirred for 1.5 hours
2. 2
   TrocknenThe organic layer was dried over sodium sulfate
3. 3
   Einengenconcentrated under reduced pressure
4. 4
   workup.ADDITIONThe residue was treated with hexane (50 ml)
5. 5
   Filtrationthe solid was filtered

Vorschrift

To a solution of 4-chloro-1-ethyl-2-iodo-benzene (5 g, 18.8 mmol) in anhydrous tetrahydrofuran (40 ml), cooled to −30° C., was added isopropyl magnesium chloride (2 M in tetrahydrofuran, 10 ml, 20 mmol) dropwise. After stirring at −30° C. for 30 minutes, trimethyl borate (4.2 ml, 38 mmol) was added dropwise and the mixture was stirred for 1.5 hours. The mixture was treated with hydrochloric acid (1 M, 25 ml), ethyl acetate (100 ml), and saturated aqueous sodium chloride solution (100 ml). The organic layer was dried over sodium sulfate and concentrated under reduced pressure. The residue was treated with hexane (50 ml) and the solid was filtered to afford 5-chloro-2-ethyl-phenyl boronic acid (1.8 g, 52% yield) as a white powder.

Quelle