Diisopropylethylamine → Ethyl (s)-3-((s)-2-(4,4-bis(trifluoromethyl)-3-(4-(3-(2-methylphenyl)ureido)-3-methoxybenzyl)-2,5-dioxoimidazolidin-1-yl)-2-(2-methylpropyl)acetylamino)-3-phenylpropionate

Participants

Reaction Steps

1.89 g (5.77 mmol) of TOTU and 932 μL of N,N-diisopropylethylamine were added at 0° C. to a solution of 3.57 g (5.77 mmol) of (S)-2-(4,4-bis(trifluoromethyl)-3-(4-(3-(2-methylphenyl)ureido)-3-methoxybenzyl)-2, 5-dioxoimidazolidin-1-yl)-2-(2-methylpropyl)acetic acid (prepared from (S)-2-(4,4-bis(trifluoromethyl)-2,5-dioxoimidazolidin-1-yl)-2-(2-methylpropyl)acetic acid and 4-(3-(2-methylphenyl)ureido)-3-methoxybenzyl chloride as described in Example 18f) and 1.11 g (5.77 mmol) of ethyl (S)-3-amino-3-phenylpropionate in 30 mL of absolute DMF. After stirring at room temperature for 1 hour, DMF was removed in vacuo, the residue was taken up in ethyl acetate and the ethyl acetate solution was washed successively with an aqueous KHSO4K2SO4 solution, a saturated NaHCO3 solution and water. After drying the organic phase over sodium sulfate and filtering, the solvent was removed in vacuo and the residue was chromatographed over silica gel using ethyl acetate/heptane (2/3). After concentration of the product fractions, 3.26 g (71%) of the title compound were obtained.

Provenance & Evidence