1208318-08-4

132434-53-8

1208318-08-4

Step 2: Synthesis of ethyl 7-(4-bromophenyl)-4,7-dioxoheptanoate (5B) 1-(4-Bromophenyl)-3-(furan-2-yl)propan-2-one (5A) (20.0 g, 72.2 mmol) was dissolved in ethanol (160 mL) and 48% aqueous hydrobromic acid (40 mL) was added. The reaction mixture was stirred under reflux conditions for 8 hours. Upon completion of the reaction, the reaction solution was concentrated under reduced pressure. The pH was adjusted to 7 by adding saturated sodium bicarbonate solution to the concentrated residue, which was subsequently extracted with ethyl acetate. The organic layers were combined, washed with saturated brine and dried over anhydrous magnesium sulfate. After filtration, the filtrate was concentrated under reduced pressure and the resulting crude product was purified by silica gel column chromatography (petroleum ether:ethyl acetate=5:1) to afford ethyl 7-(4-bromophenyl)-4,7-dioxoheptanoate (5B) as a yellow solid (7.0 g, 28% yield).