Diisopropylethylamine → 4-{4-[4-(3,3-Dimethyl-butyl)-piperazin-1-yl]-4-oxo-butyl}-3-methyl-benzoic Acid Methyl Ester

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Reaction Steps

HBTU (910 mg, 2.4 mmol) was added to a solution of 4-(3-carboxy-propyl)-3-methyl-benzoic acid methyl ester from Example E30 (378 mg, 1.6 mmol) and 1-(3,3-dimethyl-butyl)-piperazine hydrochloride from Example E4 (467 mg, 1.9 mmol) in dichloromethane (15 ml) and DIEA (0.836 ml, 4.8 mmol). The mixture was stirred for 20 h at room temperature, washed with saturated NaHCO3 then brine, dried and concentrated in vacuo. The residue was purified by flash chromatography on silica gel through an isolute (eluant; 5% methanol:95% dichloromethane) to yield the title compound (582 mg, 94%).

Provenance & Evidence