1-(2-Ethoxynaphthalen-1-yl)ethanone → 2,2-Dibromo-1-(2-ethoxy-naphthalen-1-yl)-ethanone

Temperature

0 °C

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).

1. waitat room temperature for 4.5 hours
2. washThe mixture was washed with water (200 mL)
3. extractionthe aqueous phase was extracted with diethyl ether
4. washThe combined organics were washed with water (200 mL)
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. customthe solvent removed under reduced pressure
8. customto afford a dark green sticky solid
9. customThe sticky solid was triturated with diethyl ether (100 mL)
10. filtrationfiltered

ORD record

ord-a2a4a3354b6c4a019a4763a618b012c4

Source dataset

uspto-grants-2008_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07429607B2