反应详情

Phenyltrimethylammonium tribromide (1.55 g, 4.13 mmol) was added to a solution of 2′-(benzyloxy)-4′-fluoroacetophenone (1.01 g, 4.13 mmol) in THF (10 mL), and the mixture stirred at room temperature for 45 minutes, over which time the orange solution faded and a white precipitate formed. Tlc analysis (9:1 hexane:EtOAc) showed the reaction to be complete. The mixture was poured into water (20 mL) and extracted with ether (2×50 mL). The combined ethereal extracts were dried (MgSO4) and the solvents removed in vacuo to give crude 2′-(benzyloxy)-2-bromo-4′-fluoroacetophenone as a colourless oil, which was used in the following step without purification. Rf 0.47 (9:1 hexane:EtOAc); δH (CDCl3) 7.89 (1H, dd, J=9.4 and 6.9 Hz), 7.45-7.40 (5H, m), 6.77-6.74 (2H, m), 5.15 (2H, s), 4.47 (2H, s); LCMS retention time 2.75 min, M+H+ 323.3/325.3.

1. customa white precipitate formed
2. customthe reaction
3. extractionextracted with ether (2×50 mL)
4. dry with materialThe combined ethereal extracts were dried (MgSO4)
5. customthe solvents removed in vacuo