反应详情

温度

0 °C

A solution of 17.10 g of 4-methyl-1,3-dihydrobenzimidazol-2-one in 250 ml of anhydrous N,N-dimethylformamide is admixed at 0° C. with 4.070 g of sodium hydride dispersion (60%). The reaction mixture is stirred at 0° C. over a further 30 minutes and 7.5 ml of ethyl iodide are added dropwise. The reaction mixture is stirred at 30° C. over 14 hours, poured onto 500 ml of saturated aqueous sodium hydrogencarbonate solution and extracted with ethyl acetate (2×500 ml). The combined organic phases are washed with 500 ml of brine, dried over sodium sulphate and concentrated by evaporation. The title compound is obtained as a brown solid from the residue by means of flash chromatography (SiO2 60F). Rf=0.20 (200:5:1 dichloromethane-methanol-25% conc. ammonia); Rt=3.17.

1. stirringThe reaction mixture is stirred at 30° C. over 14 hours
2. extractionextracted with ethyl acetate (2×500 ml)
3. washThe combined organic phases are washed with 500 ml of brine
4. dry with materialdried over sodium sulphate
5. concentrationconcentrated by evaporation