Sodium hydride → 1-Ethyl-4-methyl-3-(2-trimethylsilanylethoxymethyl)-1,3-dihydrobenzimidazol-2-one

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Reaction Conditions

Reaction Steps

A solution of 3.500 g of 1-ethyl-4-methyl-1,3-dihydrobenzimidazol-2-one in 40 ml of anhydrous N,N-dimethylformamide is admixed at 0° C. with 0.874 g of sodium hydride dispersion (60%). The reaction mixture is stirred at 0° C. over a further 30 minutes and 4.06 ml of 2-(trimethylsilanyl)ethoxymethyl chloride are added dropwise. The reaction mixture is stirred at 20° C. over 14 hours, poured onto 150 ml of saturated aqueous sodium hydrogencarbonate solution and extracted with tert-butyl methyl ether (2×200 ml). The combined organic phases are dried over sodium sulphate and concentrated by evaporation. The title compound is obtained as a brown oil from the residue by means of flash chromatography (SiO2 60F). Rf=0.20 (1:3 EtOAc-heptane); Rt=5.62.

Provenance & Evidence