Sodium Carbonate → Benzofuran-5-ol

Temperature

0 °C

To an ice-cooled solution of 5-methylbenzofuran (0.5 g, 3.37 mmol) in DCM (7 mL) was added boron tribromide (3.4 mL, 3.37 mmol, 1M in DCM). The light brown solution was stirred at 0° C. for 1 h, another equivalent of boron tribromide (3.4 mL) was then added. The mixture was stirred at room temperature for 2 h. TLC analysis indicated the completion of the reaction. The mixture was poured into ice and the pH was adjusted to 7 with Na2CO3. The aqueous was extracted with DCM (×2). The combined organic layers were washed with brine, dried over Na2SO4 and concentrated. The resulting light brown sold gave the satisfactory purity without further purification for next step: 0.36 g (79.6% yield), 1H NMR (400 MHz, CD3OD) δ 7.59 (d, J=2.0 Hz, 1H), 7.35 (d, J=9.2 Hz, 1H), 7.01 (d, J=2.4 Hz, 1H), 6.82 (dd, J=8.8 Hz, J=2.8 Hz, 1H), 6.67 (m, 1H), 4.73 (s, 1H).

1. stirringThe mixture was stirred at room temperature for 2 h
2. customthe completion of the reaction
3. additionThe mixture was poured into ice
4. extractionThe aqueous was extracted with DCM (×2)
5. washThe combined organic layers were washed with brine
6. dry with materialdried over Na2SO4
7. concentrationconcentrated
8. customThe resulting light brown sold gave the satisfactory purity
9. customwithout further purification for next step

ORD record

ord-bbf5106910004ecd9a131cd106e9fc88

Source dataset

uspto-grants-2011_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07919519B2