Diisopropylethylamine → (S)-2-{4'-[(4-Isopropoxy-3-methyl-benzofuran-2-carbonyl)-amino]-biphenyl-4-sulfonylamino}-3-methyl-butyric acid methyl ester

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Reaction Steps

To 200 mg (0.91 mmol) 4-isopropoxy-3-methyl-benzofuran-2-carboxylic acid in 4 mL of DMF was added 329 mg (1 eq) of (S)-2-(4′-amino-biphenyl-4-sulfonylamino)-3-methyl-butyric acid methyl ester, 482 mg (1.2 eq) of BOP, and 0.19 mL of N,N-diisopropylethylamine. The mixture was stirred at room temperature overnight. Brine was added, and the mixture was extracted with ethyl acetate. The combined organic layers were washed with brine and water. Removal of the solvent in vacuo gave the crude product, which was purified by column chromatography on silica gel to give 395 mg (69% yield) of (S)-2-{4′-[(4-Isopropoxy-3-methyl-benzofuran-2-carbonyl)-amino]-biphenyl-4-sulfonylamino}-3-methyl-butyric acid methyl ester as colorless oil.

Provenance & Evidence