Hydrochloric Acid → 2-[[[5-(Dimethylamino)-1-naphthalenyl]sulfonyl]amino]-5-[[(phenylmethoxy)carbonyl]amino]pentanoic acid

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Reaction Conditions

Reaction Steps

Nδ -Carbobenzyloxy-L-ornithine (39.6 g, 0.149 mol) was dissolved in a solution of 2N NaOH (90 mL) and tetrahydrofuran (200 mL) under nitrogen. After about 15 minutes at ambient temperature, the mixture was cooled to about 0° C. and subsequently treated with additional 2N NaOH (85 mL) and dansyl chloride (45.0 g, 0.167 mol) in 5 g portions over 15 minutes. The mixture was stirred at about 0° C. for about 1 hour and at room temperature for about 2 hours before it was neutralized to pH 7 with 1N HCl. The precipitate was suction-filtered and the filtrate was diluted with ethyl acetate. The organic phase was then separated, washed with brine, dried over Na2SO4 and concentrated to give a combined yield of 103.17 g (70.4%, two runs) of 2d as a yellow foam which was used directly.

Provenance & Evidence