Dicyclohexylcarbodiimide → Fmoc-Gly-OPfp

Participants

Reaction Steps

To a solution of Fmoc-Gly-OH (891 mg, 3.0 mmol) and PfpOH(754 mg, 4.5 mmol) in DMF (12 mL) was added DCC (845 mg, 4.5 mmol) at 0° C. for 30 min and then room temperature for 15 h. The reaction mixture was filterd to remove DCUrea and the flitrate was evaporated in vacuo to give the crude Fmoc-Gly-OPfp. To a solution of Fmoc-Gly-OPfp and BocPNA-OH (436 mg, 2.0 mmol) in DMF (16 mL) was added diisoprppylethylamine (445 il, 2.6 mmol) and the reaction mixture was stirred at room temperature for 15 h. The reaction mixture was evaporated in vacuo and the residue was flush-chromatographed (0-50% MeOH/CH2Cl2) to give Fmoc-Gly-BocPNA-OH (121 mg, 12%). 1H NMR (DMSO-d6) δ 7.88 (d, J=7.0 Hz, 2H), 7.72 (d, J=7.0 Hz, 2H), 7.62 (brt) and 7.56 (brt) (1H), 7.41 (t, J=7.0 Hz, 2H), 7.33 (t, J=7.0 Hz, 2H), 7.18 (m, 2H), 6.85 (brt) and 6.79 (brt) (1H), 4.35-4.15 (m, 3H), 4.05-3.85 (m, 3H), 3.77 (m, 1H), 3.40-3.25 (m, 2H), 3.10 (m) and 3.03 (s) (2H), 1.37 (brs, 9H); 13C NMR (DMSO-d6) δ 172.2 (d), 169.10 (d), 156.34 (d), 155.58 (d), 143.83, 140.66, 127.58, 127.04, 125.24, 120.04, 77.77 (d), 65.71, 47.34 (d), 46.72, 46.65 (d), 29.23 (d), 28.14 (d); FABMS m/z 498 [(M+H)+].

Provenance & Evidence