Diisopropylethylamine → HCID 66899848, Verbindung

Beteiligte Stoffe

Reaktionsschritte

(2S,4S)-2-t-butoxycarbonylamino-4-ethoxy-pentanoic acid (401 mg, 1.536 mmol) was mixed with 1-(3-amino-pyrazol-1-yl)-2-methyl-propan-2-ol (prepared in U.S. Pat. Appl. US2008021032 Example 80, 334 mg, 2.16 mmol) in N,N-dimethylformamide (10 mL). benzotriazol-1-yl-oxy-tris(dimethylamino)phosphonium hexafluorophosphate (1.23 g, 2.77 mmol) and N,N-diisopropylethylamine (0.7 mL) was added at 0° C. The mixture was stirred at room temperature overnight. Solvents were evaporated and the residue was extracted with ethyl acetate and saturated sodium chloride solution. The solvents were evaporated and the crude material was purified by flash column chromatography (silica gel, 10-80% ethyl acetate/hexanes) to afford {(1S,3S)-3-ethoxy-1-[1-(2-hydroxy-2-methyl-propyl)-1H-pyrazol-3-ylcarbamoyl]-butyl}-carbamic acid t-butyl ester (486 mg, 80%) as a white solid: LR-ES-MS m/z calculated for C19H34N4O5 [M]+ 398, observed [M+H]+ 399.

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