1,3-Dibromopropane → 6-(3-Bromopropoxy)-3-methyl-1-benzofuran

Temperature

80 °C

To a solution of 3-methyl-1-benzofuran-6-ol (0.20 g, 1.35 mmol) in NaOH (6 M aqueous solution, 0.25 mL) was added 1,3-dibromopropane (0.48 mL, 0.46 mmol), and the mixture was heated at 80° C. for 2 h. The reaction mixture was cooled to rt, and NaOH (6 M aqueous solution, 0.11 mL) was added. The reaction mixture was heated at 80° C. for 1 h, cooled to rt, and partitioned between CH2Cl2 and NaHCO3 (saturated aqueous solution). The organic layer was dried, filtered, concentrated under reduced pressure, and purified by silica gel column chromatography (EtOAc/hexane (v/v)=1:19) to give 210 mg (58%) of the title compound containing minor impurities. This material was used in next step without further purification. 1H NMR (300 MHz, CDCl3): δ 7.38 (d, 1H), 7.32 (s, 1H), 7.0 (s, 1H), 6.88 (dd, 1H), 4.14 (t, 2H), 3.62 (t, 2H), 2.40-2.28 (m, 2H), 2.20 (s, 3).

1. temperatureThe reaction mixture was cooled to rt
2. temperatureThe reaction mixture was heated at 80° C. for 1 h
3. temperaturecooled to rt
4. custompartitioned between CH2Cl2 and NaHCO3 (saturated aqueous solution)
5. customThe organic layer was dried
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. custompurified by silica gel column chromatography (EtOAc/hexane (v/v)=1:19)

ORD record

ord-ebf929ad36364908a89205677f5736aa

Source dataset

uspto-grants-2010_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07714004B2