Triethylamine → Nalpha-BOC-Nepsilon-CBZ-L-lysyl-L-alanine amide

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Reaction Steps

Referring to Scheme 6, a solution of 5.0 g (0.010 mol) of Nα-BOC-Nε-CBZ-L-lysine p-nitrophenyl ester and 1.5 g (0.012 mol) of L-alanine amide hydrochloride and 1.67 ml (0.012 mol) of triethylamine in anhydrous N,N-dimethylformamide (50 mi) was stirred at room temperature for 16 hours before the solvent was removed in vacuo. The resulting residue was dissolved in ethyl acetate (200 ml) and washed with 3M NaOH (3×100 ml), water (3×100 ml), 1M HCl (2×100 ml) and finally with brine (100 ml). After drying over anhydrous sodium sulfate, the solution was filtered and concentrated in vacuo to give 4.3 g (96% yield) of Nα-BOC-Nε-CBZ-L-lysyl-L-alanine amide (6a) as a white solid. TLC: Rf 0.32 (chloroform-isopropanol 9:1); 1H NMR (d6 -DMSO) δ 1.20(d,3H), 1.35(bm, 6H), 1.37(s,9H), 2.97(m,2H), 3.86(m,1H), 4.21(m,1H), 5.00(s,2H), 6.95(d,1H), 7.06(s, 1H), 7.24(t,1H), 7.34(m,6H), 7.78(d,1H); 13C NMR (d6 -DMSO) δ 18.6, 22.8, 28.2, 29.2, 31.4, 40.1, 47.8, 54.5, 65.2, 78.2, 127.8, 128.4, 137.3, 155.5, 156.1, 171.7, 174.2.

Provenance & Evidence