反应详情

A solution of 2-mercapto-5-fluoro-benzimidazole (2.24 g, 13.3 mmol) in tetrahydrofuran (10 ml) is added dropwise to a mixture of sodium hydride (60% dispersion in mineral oil, 0.852 g, 21.3 mmol) and tetrahydrofuran (5 ml). The mixture is stirred at room temperature for 2 hours. A solution of 5-nitro-2-furaldehyde (1.88 g, 13.3 mmol) in tetrahydrofuran (15 ml) is then added dropwise over a 15 minute period and the mixture is stirred for 2 hours at room temperature. The reaction mixture is concentrated under reduced pressure and the residue is dissolved in 200 ml of ethyl acetate and washed with water (2×60 ml). The organic phase is dried over MgSO4 and concentrated under reduced pressure. The residue is purified on a silica gel column (40 g) eluted with dichloromethane to yield 700 mg of 5-(5-fluoro-1H-benzoimidazol-2-ylsulfanyl)-furan-2-carbaldehyde as an orange powder. Yield=20%. Analytical LC/MS (method B): retention time=3.08 min., m/z=263.05 (positive ion mode).

1. stirringthe mixture is stirred for 2 hours at room temperature
2. concentrationThe reaction mixture is concentrated under reduced pressure
3. dissolutionthe residue is dissolved in 200 ml of ethyl acetate
4. washwashed with water (2×60 ml)
5. dry with materialThe organic phase is dried over MgSO4
6. concentrationconcentrated under reduced pressure
7. customThe residue is purified on a silica gel column (40 g)
8. washeluted with dichloromethane