Hydrochloric Acid → (2S,4R)-4-amino-5-biphenyl-4-yl-2-hydroxymethyl-2-methyl-pentanoic acid 2-piperidin-1-yl-ethyl ester

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Reaction Steps

(2S,4R)-5-Biphenyl-4-yl-4-t-butoxycarbonylamino-2-hydroxymethyl-2-methyl-pentanoic acid (125 mg, 302 μmol), HOBt (240 mg, 1.8 mmol), and EDCI (320 μL, 1.8 mmol) were dissolved in DCM and stirred for 2 minutes. N-(2-Hydroxyethyl)piperidine (401 μL, 3.0 mmol) was added and the resulting mixture was stirred at room temperature for 3 hours. The mixture was diluted with DCM and washed with saturated aqueous NaHCO3 solution. The organic layer was separated, dried, concentrated, then purified (Interchim reverse phase chromatography column; 5-70% MeCN in water with 0.5% TFA). The purified material was combined with MeCN (3.0 mL, 58 mmol) and 4 M HCl in dioxane (0.3 mL, 1.2 mmol) and the resulting mixture was stirred at room temperature for 30 minutes. The solvent was removed and azeotroped with toluene (2×) to yield (2S,4R)-4-amino-5-biphenyl-4-yl-2-hydroxymethyl-2-methyl-pentanoic acid 2-piperidin-1-yl-ethyl ester.

Provenance & Evidence