1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → Di-tert-butyl N-(3-(2-(5-(tert-butoxycarbonyl)-5-(2-tert-butoxy-2-oxoethyl)-4,5-dihydro-1,2-oxazol-3-yl)-4-hydroxyphenyl)propanoyl)-L-aspartate

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Reaction Steps

A mixture of 3-(2-(5-(tert-butoxycarbonyl)-5-(2-tert-butoxy-2-oxoethyl)-4,5-dihydro-1,2-oxazol-3-yl)-4-hydroxyphenyl)propanoic acid (214 mg), di-tert-butyl L-aspartate hydrochloride (161 mg), WSC (89 mg), HOBt (77 mg), triethylamine (0.080 mL), and DMF (2 mL) was stirred at room temperature for 3 days. To the reaction mixture, water was added, followed by extraction with ethyl acetate. The extract was washed with brine and dried over anhydrous magnesium sulfate, and then, the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/hexane) to obtain the title compound (154 mg).

Provenance & Evidence