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

Temperature

100 °C

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).

1. temperatureThe mixture was cooled to room temperature
2. additionpoured onto ice
3. extractionextracted with Et2O (2×200 mL)
4. washThe combined organic extracts were washed with saturated aq. NaHCO3 and brine
5. dry with materialThe solution was dried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated
8. customThe residue was purified by flash chromatography (100% hexanes)

ORD record

ord-50d4b31ea8164fcb93de0e9320dcf1d2

Source dataset

uspto-grants-2000_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06017926