Diisopropylethylamine → (R)-4-{(S)-4-Carboxy-2-[(5-{2-[(S)-2-(Cyclopropylmethyl carbamoyl)-pyrrolidin-1-yl]-2-oxo-ethoxy}-1-phenyl-1H-pyrazole-3-carbonyl)-amino]-butyryl}-2-methyl-piperazine-1-carboxylic acid ethyl ester

Participants

Reaction Steps

To a solution of 100 mg (S)-2-({5-[2-((S)-2-(Cyclopropylmethyl-carbamoyl)-pyrrolidin-1-yl)-2-oxo-ethoxy]-1-phenyl-1H-pyrazole-3-carbonyl}-amino)-pentanedioic acid 5-tert-butyl ester in 6 ml DMF were added 28 μl DIPEA, 64 mg HATU and 29 mg (R)-2-Methyl-piperazine-1-carboxylic acid ethyl ester. After stirring for 16 h the solution was concentrated, the residue dissolved in 1.5 ml dichloromethane and treated with 560 μl TFA. After stirring for 16 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: 65 mg MS (ES+): m/e=696.

Provenance & Evidence