Imidazole → t-butyldiphenylsilyloxy-N-carbobenzyloxy-L-serine methyl ester

Participants

Reaction Steps

Subsequently, to a solution of N-carbobenzyloxy-L-serine methyl ester (4.40 g, 16.7 mmol) in dimethylformamide (210 ml) were added t-butyldiphenylsilyl chloride (5.20 ml, 20.0 mmol) and imidazole (1.36 g, 20.0 mmol) in an ice bath, and the mixture was stirred at room temperature for 3 days. After checking the completion of the reaction, the reaction mixture was partitioned between ethyl acetate and 10% aqueous sodium chloride solution. The organic layer was washed successively with saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by chromatography on a silica gel column using n-hexane:ethyl acetate (8:1→6:1) as the eluant to afford t-butyldiphenylsilyloxy-N-carbobenzyloxy-L-serine methyl ester (18.8 g, 99%).

Provenance & Evidence