1,3-Dibromopropane → 6-(3-Bromopropoxy)-3-methyl-1-benzofuran
Reaction equation
[CH3:1][C:2]1[C:6]2[CH:7]=[CH:8][C:9]([OH:11])=[CH:10][C:5]=2[O:4][CH:3]=1.[Br:12][CH2:13][CH2:14][CH2:15]Br>[OH-].[Na+]>[Br:12][CH2:13][CH2:14][CH2:15][O:11][C:9]1[CH:8]=[CH:7][C:6]2[C:2]([CH3:1])=[CH:3][O:4][C:5]=2[CH:10]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 80 °C
Procedure
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, 3H).