Reaktion #61842

Reaktionsgleichung

1-(2-ethoxy-naphthalen-1-yl)-ethanone

phenyl trimethylammonium tribromide

→

2,2-dibromo-1-(2-ethoxy-naphthalen-1-yl)-ethanone

Ausbeute 43.9%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITat room temperature for 4.5 hours
2. 2
   WaschenThe mixture was washed with water (200 mL)
3. 3
   Extraktionthe aqueous phase was extracted with diethyl ether
4. 4
   WaschenThe combined organics were washed with water (200 mL)
5. 5
   Trocknendried over magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   Sonstigethe solvent removed under reduced pressure
8. 8
   Sonstigeto afford a dark green sticky solid
9. 9
   SonstigeThe sticky solid was triturated with diethyl ether (100 mL)
10. 10
    Filtrationfiltered

Vorschrift

To a solution of 1-(2-ethoxy-naphthalen-1-yl)-ethanone (26 g) in tetrahydrofuran (200 mL) at 0° C. was added phenyl trimethylammonium tribromide (50 g). The mixture was stirred at 0° C. for 10 minutes and then at room temperature for 4.5 hours. The mixture was washed with water (200 mL) and the aqueous phase was extracted with diethyl ether. The combined organics were washed with water (200 mL), dried over magnesium sulfate, filtered and the solvent removed under reduced pressure to afford a dark green sticky solid. The sticky solid was triturated with diethyl ether (100 mL) and filtered to give 2,2-dibromo-1-(2-ethoxy-naphthalen-1-yl)-ethanone (12.6 g, 35%) as an off-white solid. The filtrate was evaporated to a dark green oil and purified by column chromatography, elution with 40% to 60% dichloromethane in cyclohexane, affording 2-bromo-1-(2-ethoxy-naphthalen-1-yl)-ethanone (15.8 g, 44%) as an off-white solid. 1H NMR (CDCl3): 1.45 (3H, m), 4.2 (2H, m), 4.5 (2H, m), 7.2 (1H, m), 7.4 (1H, m), 7.5 (1H, m), 7.8 (2H, m), 7.9 (1H, m).

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