反应详情

To 80 mg (0.33 mmol) of 5-chloro-4-methoxy-3-methyl-benzofuran-2-carboxylic acid was added 2 mL of oxalyl chloride and the mixture refluxed for 2 h, then stirred room temperature overnight. The excess oxalyl chloride was removed under vacuum. The residue was dissolved in 2 mL of dichloromethane and was added to a mixture of 181 mg (0.5 mmol) of (S)-2-(4′-amino-biphenyl-4-sulfonylamino)-3-methyl-butyric acid methyl ester and 1 mL of pyridine in an ice/water bath. The mixture was stirred at 0° C. overnight. The reaction mixture was diluted with dichloromethane and was washed with 2N HCl, and water. Removal of the solvent in vacuo gave the crude product which was purified by column chromatography to give 168 mg (86% yield) of (S)-2-{4′-[(5-chloro-4-methoxy-3-methyl-benzofuran-2-carbonyl)-amino]-biphenyl-4-sulfonylamino}-3-methyl-butyric acid methyl ester as a white solid.

1. temperaturethe mixture refluxed for 2 h
2. customThe excess oxalyl chloride was removed under vacuum
3. dissolutionThe residue was dissolved in 2 mL of dichloromethane
4. stirringThe mixture was stirred at 0° C. overnight
5. washwas washed with 2N HCl, and water
6. customRemoval of the solvent in vacuo
7. customgave the crude product which
8. customwas purified by column chromatography