Reaktion #11166

Reaktionsgleichung

(2,6-dichloro-4-methoxyphenyl)methanol

HBr

triphenylphosphine

→

phosphonium

Ausbeute 100.0%

(2,6-Dichloro-4-methoxybenzyl)(triphenyl)phosphonium bromide

Ausbeute 100.0%

Lösungsmittel

acetic acid

benzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONpoured onto ice-water (120 mL)
2. 2
   Extraktionextracted with pentane (6×100 mL)
3. 3
   WaschenThe extracts were washed with water (3×200 mL)
4. 4
   SonstigeRemoval of the solvent
5. 5
   Sonstigegave the crude bromide as white crystals, which
6. 6
   Temperaturat reflux for 15 h
7. 7
   TemperaturAfter cooling
8. 8
   Filtrationthe precipitate was collected by filtration
9. 9
   Waschenwashing thoroughly with dry benzene
10. 10
    Trocknenpentane, and dried under vacuum at 50° C.

Vorschrift

A solution of (2,6-dichloro-4-methoxyphenyl)methanol (3.00 g, 14.5 mmol) in 30% HBr in acetic acid (45 mL) was stirred at 20° C. for 3 h, then poured onto ice-water (120 mL) and extracted with pentane (6×100 mL). The extracts were washed with water (3×200 mL), backextracting with pentane (100 mL). Removal of the solvent gave the crude bromide as white crystals, which was immediately redissolved in benzene (80 mL) and treated with triphenylphosphine (5.70 g, 21.7 mmol), stirring at reflux for 15 h. After cooling, the precipitate was collected by filtration, washing thoroughly with dry benzene, then pentane, and dried under vacuum at 50° C. to give the phosphonium salt (521) as a white solid (7.75 g, 100%), mp (CH2Cl2/benzene) 188–190° C. 1H NMR (CDC3) δ 7.83–7.60 (m, 15H), 6.74 (s, 2H), 5.37 (d, J=13.5 Hz, 2H), 3.76 (s, 3H). Found: C, 58.40; H, 4.35. C26H22BrCl2OP requires C, 58.67; H, 4.17.

Quelle