1-Hydroxybenzotriazole → N-[2,6-dichloro-4-[[[(1R)-1-(1-naphthalenyl) ethyl]amino]carbonyl]benzoyl]-3-[(thiophene-2-carbonyl)amino]-L-alanine, methyl ester

Participants

Reaction Steps

A solution of 2,6-dichloro-4-[[[(1R)-1-(1-naphthalenyl)ethyl]amino]carbonyl]benzoic acid (Example 38; 1.00 g, 2.6 mmol), 3-(thiophene-2-carbonyl)amino-L-alanine, methyl ester hydrochloride (Example 301; 680 mg, 2.6 mmol), HBTU (1.27 g, 3.35 mmol), HOBT (450 mg, 3.3 mmol), and diisopropylethylamine (1.33 g, 10.3 mmol) in N,N-dimethylformamide (20 mL) was stirred at room temperature over the weekend. The solvent was evaporated and ethyl acetate (200 mL) was added. The solution was washed with 1 M HCl (100 mL), saturated aqueous sodium hydrogen carbonate (Note: some material was lost due to effervescence at this stage) and brine (200 mL each), then dried (MgSO4), filtered, evaporated and chromatographed (70% ethyl acetate/hexanes) to give N-[2,6-dichloro-4-[[[(1R)-1-(1-naphthalenyl)ethyl]amino]carbonyl]benzoyl]-3-[(thiophene-2-carbonyl)amino]-L-alanine, methyl ester (260 mg, 17%) as a white solid.

Provenance & Evidence