3-Amino-5-chloro-2-hydroxybenzenesulfonic acid → (2S)-2-amino-4-[(5-chloro-2-hydroxy-3-sulfophenyl)carbamoyl]butanoic acid

Participants

Reaction Steps

Boc-Glu-OtBu (100 mg, 0.33 mmol) and HOBt hydrate (65.6 mg, 0.43 mmol) were dissolved in 2 mL of DMF, and triethylamine (0.137 mL) was added thereto. After cooling the mixture down to 0° C., diisopropylcarbodiimide (66.4 μL, 0.43 mmol) and 2-amino-4-chlorophenol-6-sulfonic acid (73.7 mg, 0.33 mmol) were added thereto and stirred overnight at room temperature. After removing a solvent, purification was conducted in accordance with the purification process A. The obtained intermediate was dissolved in 2 mL of TFA and stirred at room temperature for 2 hours. 2 mL of methylene chloride was added thereto, and a precipitate was taken by filtration to obtain a title compound.

Provenance & Evidence