Isopropylamine → 4-((S)-4-Carboxy-2-{[5-(1-isopropylcarbamoyl-cyclobutoxy)-1-phenyl-1H-pyrazole-3-carbonyl]-amino}-butyryl)-piperazine-1-carboxylic acid ethyl ester

Participants

Reaction Steps

To a solution of 50 mg of 4-((S)-4-tert-Butoxycarbonyl-2-{[5-(1-carboxy-cyclobutoxy)-1-phenyl-1H-pyrazole-3-carbonyl]-amino}-butyryl)-piperazine-1-carboxylic acid ethyl ester in 0.3 ml of DMF, 28 mg of TOTU, 36 mg of NEM and 10 mg of isopropylamine was added. The reaction mixture was allowed to stir at RT for 16 h. Then, the reaction mixture was diluted with water and filtered through a Chem Elut® cartridge by eluting with ethyl acetate. 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. This residue was dissolved in 1 ml of DCM, 0.2 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 dissolved in 3 ml of water and lyophilized to yield a white solid.

Provenance & Evidence