反应详情

A mixture comprising of 3,4-diaminophenol (3.661 g, 29.5 mL), ethyl 2-(N-ethoxyamidino)propionate (7.423 g, 38.4 mmol) and ethanol (30 mL) was heated at reflux for 6 hours and concentrated in vacuo. The residue was dissolved in ethyl acetate (200 mL) and the solution was washed with saturated aqueous sodium hydrogencarbonate (3×20 mL) and brine (1×20 mL), dried (MgSO4) and concentrated in vacuo to provide ethyl 2-(5-hydroxy-1H-benzoimidazol-2-yl)propionate (6.3 g, 91% yield) as a dark solid. The solid was further purified by silica gel flash chromatography (100% ethyl acetate); MS (PB-PCI) C12H14N2O3 m/e calc 234.28; found 235 (MH+).

1. temperatureat reflux for 6 hours
2. concentrationconcentrated in vacuo
3. dissolutionThe residue was dissolved in ethyl acetate (200 mL)
4. washthe solution was washed with saturated aqueous sodium hydrogencarbonate (3×20 mL) and brine (1×20 mL)
5. dry with materialdried (MgSO4)
6. concentrationconcentrated in vacuo