Imidazole → Benzyl N-(2-t-Butyldimethylsilyloxy-1-methylethyl)-carbamate

Participants

Reaction Steps

A solution of 13.72 g of t-butyldimethylsilyl chloride in 50 ml of dimethylformamide was added dropwise, whilst ice-cooling, to a mixture of 16.0 g of 2-benzyloxycarbonylaminopropanol (prepared as described in Preparation 7), 12.39 g of imidazole and 150 ml of dimethylformamide. The mixture was then stirred at room temperature for 6.5 hours. At the end of this time, the dimethylformamide was removed from the reaction mixture by evaporation under reduced pressure, and water was added to the resulting residue, which was then extracted with ethyl acetate. The extract was washed with an aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. The ethyl acetate was removed from the extract by evaporation under reduced pressure, and the resulting residue was purified by silica gel column chromatography, using a 1:6 by volume mixture of ethyl acetate and hexane as the eluent, to give 23.89 g of the title compound, melting at 68.0° C. to 70.2° C.

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