Triethylamine → (2S,4R)-4-tert-butoxy-2-(2,2-dimethoxy-ethylcarbamoyl)-pyrrolidine-1-carboxylic acid benzyl ester

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Reaction Steps

To a stirred solution of (2S,4R)-4-tert-butoxy-pyrrolidine-1,2-dicarboxylic acid 1-benzyl ester (500 mg, 1.56 mmol) and 2,2-dimethoxy-ethylamine (163 mg, 1.56 mmol) in dichloromethane (5 mL) were added EDC-HCl (298 mg, 1.56 mmol), HOBt (210 mg, 1.56 mmol) and triethylamine (157 mg, 1.56 mmol). The mixture was stirred at room temp. for 24 h, diluted with water, extracted with ethyl acetate and washed with water and brine. The organic layer was dried over anhydrous sodium sulfate, filtered, concentrated and purified by column chromatography (using 15% EtOAc in hexane as eluent) to give (2S,4R)-4-tert-butoxy-2-(2,2-dimethoxy-ethylcarbamoyl)-pyrrolidine-1 -carboxylic acid benzyl ester (200 mg, 31.6% yield) as a light brown liquid. MS calcd. for C21H33N2O6 [(M+H)+] 409.0, obsd. 409.0.

Provenance & Evidence