1-Bromo-3-(2,2-diethoxyethoxy)benzene → 6-Bromo-1-benzofuran

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Reaction Conditions

Reaction Steps

To a solution of the acetal 1-2 in toluene (200 mL) was added polyphosphoric acid (20 g). The biphasic mixture was heated to 100° C. and stirred at this temperature for 4 h. The mixture was cooled to room temperature, poured onto ice, and extracted with Et2O (2×200 mL). The combined organic extracts were washed with saturated aq. NaHCO3 and brine. The solution was dried over MgSO4, filtered, and concentrated. The residue was purified by flash chromatography (100% hexanes) to give the product 1-3 as a yellow oil. TLC Rf=0.3 (100% hexanes). 1H NMR (300 MHz, CDCl3) δ 7.68 (s, 1H), 7.60 (d, 1H, J=2.1 Hz), 7.46 (d, 1H, J=8.4 Hz), 7.36 (dd, 1H, J=8.1, 1.5 Hz), 6.75 (dd, 1H, J=7.1, 0.9 Hz).

Provenance & Evidence