反应详情

A solution of 2-mercapto-5-trifluoromethoxy-benzimidazole (1.26 g, 5.38 mmol) in tetrahydrofuran (10 ml) is added dropwise to a mixture of sodium hydride (60% dispersion in mineral oil, 0.344 g, 8.61 mmol) and tetrahydrofuran (5 ml) at 0° C. The mixture is stirred at room temperature for 2 hours. A solution of 5-nitro-2-furaldehyde (0.76 g, 5.38 mmol) in tetrahydrofuran (15 ml) is then added dropwise over a 15 minute period and the mixture is stirred for 16 hours at room temperature. The reaction mixture is concentrated under reduced pressure and the residue is dissolved in 10 ml of dichloromethane and filtered through a silica gel plug (40 ml). The silica gel plug is eluted with 800 ml of cylohexane/ethyl acetate (7/3, v/v). The organic filtrates are combined and concentrated under reduced pressure to yield 1.1 g of 5-(5-trifluoromethoxy-1H-benzoimidazol-2-ylsulfanyl)-furan-2-carbaldehyde as an oil. Yield=62%. Analytical LC/MS (method B): retention time=3.77 min., m/z=329.0 (positive ion mode).

1. stirringthe mixture is stirred for 16 hours at room temperature
2. concentrationThe reaction mixture is concentrated under reduced pressure
3. dissolutionthe residue is dissolved in 10 ml of dichloromethane
4. filtrationfiltered through a silica gel plug (40 ml)
5. washThe silica gel plug is eluted with 800 ml of cylohexane/ethyl acetate (7/3
6. concentrationconcentrated under reduced pressure