反应详情

To a cooled (0° C.) suspension of 5-(hydroxymethyl)-benzimidazole (920 mg, 6.2 mmol) in THF (12 mL) was added sequentially DPPA (1.46 mL, 6.8 mmol) and DBU (1.11 mL, 7.4 mmol). The resulting solution was heated to reflux for 5 h, cooled to RT, and concentrated in vacuo. The residue was partitioned between sodium bicarbonate and ethyl acetate. The organic layer was washed with brine, dried (Na2SO4), and concentrated in vacuo. Silica gel chromatography (15% MeOH—CHCl3), afforded the title compound as a brown solid: Rf (8:1:1 EtOAc-MeOH—NH4H)=0.31; m.p. 110-114° C.; 1H NMR (400 MHz, DMSO-d6): δ8.25 (s, 1H), 7.27 (d, J=8.4, 1H), 7.62-7.60 (m, 2H), 7.20 (d, J=8.2 Hz, 1H), 8.24 (s, 1H); HRMS (FAB) C8H8N5 calcd. 174.1847 (M+1). Found 174.1222.

1. temperatureTo a cooled
2. temperatureThe resulting solution was heated
3. temperatureto reflux for 5 h
4. concentrationconcentrated in vacuo
5. customThe residue was partitioned between sodium bicarbonate and ethyl acetate
6. washThe organic layer was washed with brine
7. dry with materialdried (Na2SO4)
8. concentrationconcentrated in vacuo