Toluene → (4S)-4-([5-[1-(ethoxycarbonyl)cyclobutoxy]-1-phenyl-1H-pyrazol-3-yl]formamido)-5-[4-(ethoxycarbonyl)piperazin-1-yl]-5-oxopentanoic acid

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Reaction Steps

To a solution of 860 mg of 4-((S)-4-tert-Butoxycarbonyl-2-{[5-(1-ethoxycarbonyl-cyclobutoxy)-1-phenyl-1H-pyrazole-3-carbonyl]-amino}-butyryl)-piperazine-1-carboxylic acid ethyl ester in 5 ml of DCM, 0.8 ml of TFA was added at RT. After 4 h 20 ml of toluene was added and the solvents were removed under reduced pressure. The residue was purified by preparative HPLC (C18 reverse phase column, elution with a water/MeCN gradient with 0.1% TFA). The fractions containing the product were evaporated and lyophilized to yield a white solid. Yield: 320 mg

Provenance & Evidence