Water → 2-[4-(4-Bromophenoxymethyl)-2,5-dioxo-imidazolidin-1-yl]-3-methyl-butyric acid methyl ester

関与物質

反応手順

The compound obtained in step f above (22f) (900 mg, 1.907 mmol) was stirred in TFA (8 mL) at 0° C. for 5 h, and then concentrated under vacuum. The residue was diluted with CH2Cl2, washed with saturated NaHCO3 and brine, dried over anhydrous Na2SO4, concentrated to give the crude product. The obtained crude product was stirred in dioxane (9 mL) and water (1 mL) at 0° C., DIEA (737 mg, 5.72 mmol) and phenyl chloroformate (446 mg, 2.861 mmol) were added, and the mixture was stirred for 1.5 h. The solvent was removed under vacuum; the residue was diluted with EtOAc and washed with brine. The combined organic layers were dried and concentrated to give a yellow oil. The obtained oil was then stirred with DIEA (737 mg, 5.72 mmol) in DMF (10 mL) for 24 h. After general workup, the crude product was purified by silica gel column chromatography to give the title compound as colorless oil (245 mg, 32% from step f.

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