Diisopropylethylamine → 3-[(S)-4-Carboxy-2-({5-[2-((S)-2-cyclobutylcarbamoyl-pyrrolidin-1-yl)-2-oxo-ethoxy]-1-phenyl-1H-pyrazole-3-carbonyl}-amino)-butyrylamino]-pyrrolidine-1-carboxylic acid butyl ester

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Reaction Steps

To a solution of 303 mg (S)-2-({5-[2-((S)-2-cyclobutylcarbamoyl-pyrrolidin-1-yl)-2-oxo-ethoxy]-1-phenyl-1H-pyrazole-3-carbonyl}-amino)-pentanedioic acid 5-tert-butyl ester in 5 ml DMF were added 34 μl DIPEA, 193 mg HATU and 103 mg 3-amino-pyrrolidine-1-carboxylic acid butyl ester. After stirring for 12 h the reaction mixture was diluted with ethyl acetate, washed with aqueous LiCl (4%) and saturated NaHCO3 solution. The solution was concentrated, dissolved in dichloromethane and stirred in the presence of 384 μl TFA. After stirring for 4 h the solvents were removed under reduced pressure and the residue purified by preparative HPLC (C18 reverse phase column, elution with a water/MeCN gradient with 0.1% TFA). The fractions containing the product were lyophilized to yield the pure product. Yield: 290 mg MS (ES+): m/e=710.

Provenance & Evidence