No. 5317776, 1-tert-butyl (S)-2-{(E)-(S)-1-[(S)-2-(4-but-2-ynyloxy-phenyl)-1-methoxycarbonyl-ethylcarbamoyl]-10-oxo-heptadec-2-enyl}-2-hydroxy-succinate (40.6 mg, 56.9 nmol) was dissolved in DMF (1.0 mL), and ammonium chloride (9.13 mg, 170.6 nmol), WSC (16.4 mg, 85.3 nmol), HOBt (11.5 mg, 85.3 nmol), N,N-diisopropylethylamine (59.4 mL, 341.2 nmol) were added. The mixture was stirred at room temperature for 20 hours. To the reaction solution was added water. The mixture was extracted with ethyl acetate, washed with 1 M hydrochloric acid, an aqueous solution of sodium bicarbonate, and a saturated brine. The organic layer was dried over anhydrous magnesium sulfate. The solvent was then distilled off under reduced pressure.
