1-Hydroxybenzotriazole → 2,6-dichloro-4-[[[(1R)-1-(1-naphthalenyl)ethyl]amino)carbonyl]benzoic acid, methyl ester

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Reaction Steps

A solution of 2,6-dichlorobenzene-1,4-dicarboxylic acid, 1-methyl ester (Example 4; 3.00 g, 12.0 mmol), ®-(+)-1-(1-naphthyl)ethylamine (2.00 g, 11.7 mmol), HBTU (5.68 g, 15.0 mmol), HOBT (2.04 g, 15.1 mmol), and diisopropylethylamine (6.20 g, 48.0 mmol) in N,N-dimethylformamide (50 mL) was stirred at room temperature over the weekend. The solvent was evaporated and ethyl acetate (150 mL) was added. The solution was washed with 1 M HCl (100 mL) and the aqueous layer was back-extracted with ethyl acetate (100 mL). The combined organic layers were washed with saturated aqueous sodium hydrogen carbonate and brine (200 mL each), then dried (MgSO4), filtered, evaporated and chromatographed (30% ethyl acetate/hexanes) to give 2,6-dichloro-4-[[[(1R)-1-(1-naphthalenyl)ethyl]amino]carbonyl]benzoic acid, methyl ester (4.52 g, 96%) as a white foam.

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