1-Naphthylglycine → (3S)-3-[N-((1-Naphthylamino)Acetyl)Leucinyl]Amino-4-Oxobutanoic Acid tert-Butyl Ester Semicarbazone

Participants

Reaction Conditions

Reaction Steps

To a solution of (1-naphthylamino)acetic acid (0.076 g, 0.38 mmol) and (3S)-3-(leucinyl)amino-4-oxobutanoic acid tert-butyl ester semicarbazone (see Example 1, Part B, 0.180 g, ca 0.41 mmol) in N-methylpyrrolidone(1.0 mL)-CH2Cl2(1.0 mL) at 0° C. (ice bath) under nitrogen was added hydroxybenzotriazole hydrate (0.075 g) followed by 1-ethyl-3-(3′,3′-dimethyl-1′-aminopropyl)carbodiimide hydrochloride (0.100 g, 0.52 mmol). After stirring at 0° C. for 3 hrs and at room temperature for 16 hrs, the mixture was partitioned between EtOAc-water. The organic phase was washed with water, 5% KHSO4, saturated NaHCO3 and saturated NaCl solutions, dried over anhydrous Na2SO4 and evaporated to dryness. The crude product was purified by flash chromatography eluting with MeOH-CH2Cl2 (1:30 then 1:15) to give the title compound (0.201 g, 100%) as a pale yellow foam. TLC(MeOH-CH2Cl2; 5:95) Rf=0.29.

Provenance & Evidence