N-(tert-butoxycarbonyl)glycine → (S)-Methyl 16,16-dimethyl-3,11,14-trioxo-1-phenyl-2,15-dioxa-4,10,13-triazahepta decane-9-carboxylate

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Reaction Steps

To a solution of L-Lys(Z)OMe 40 (1.05 g, 2.6 mmol) in dry DMF (40 mL) was added Boc-GlyOH (494 mg, 2.8 mmol), HATU (977 mg, 2.57 mmol), and DIEA (2.03 mL, 11.7 mmol). The mixture was stirred at rt overnight. The solvent was then removed in vacuo and the residue was dissolved in EtOAc (100 mL) and washed with saturated NaHCO3 solution water and brine. The organic layer was dried over MgSO4, filtered and concentrated in vacuo. The crude compound was purified on column of silica gel (2% MeOH/DCM) to give the subject compound (960 mg, yield 90%). Intermediate 41 was characterized by the following spectroscopic data: 1H NMR (DMSO-d6, 300 MHz) δ (ppm) 8.12 (t, 1H), 7.98 (t, 1H), 7.47-7.38 (m, 5H), 6.98 (t, 1H), 5.13 (s, 2H), 4.56 (m, 1H), 4.05 (d, 2H), 3.65 (s, 3H), 3.02 (m, 2H), 1.90 (m, 2H), 1.55 (m, 2H), 1.38 (s, 9H), 1.25 (m, 2H).

Provenance & Evidence