Oxalyl chloride → (S)-2-{4'-[(5-bromo-4-methoxy-3-methyl-benzofuran-2-carbonyl)-amino]-biphenyl-4-sulfonylamino}-3-methyl-butyric acid methyl ester

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Reaction Conditions

Reaction Steps

To 40 mg (0.14 mmol) of 5-bromo-4-methoxy-3-methyl-benzofuran-2-carboxylic acid was added 0.5 mL of oxalyl chloride and the mixture was refluxed for 2 h, then the excess oxalyl chloride was removed by vacuum. The residue was dissolved in 0.5 mL of dichloromethane and was added to a mixture of 92 mg (0.25 mmol) of (S)-2-(4′-amino-biphenyl-4-sulfonylamino)-3-methyl-butyric acid methyl ester, 34 mg (0.28 mmol) of 4-(dimethylamino)pyridine and 1 mL of dichloromethane in an ice/water bath. The mixture was stirred at 0° C. for overnight. The mixture was diluted with dichloromethane and was washed with 2N HCl, and water. Removal of the solvent from the organic solution gave 20 mg (23% yield) of (S)-2-{4′-[(5-bromo-4-methoxy-3-methyl-benzofuran-2-carbonyl)-amino]-biphenyl-4-sulfonylamino}-3-methyl-butyric acid methyl ester as an off-white solid.

Provenance & Evidence