4-Methylmorpholine → Lysylthreonine

Participants

Reaction Steps

Amine 6 (790 mg, 1.68 mmol) and Fmoc-Ala-OH (578 mg, 1.86 mmol) were dissolved in 40 mL of dry dichloromethane. 1-Hydroxybenzotriazole hydrate (342 mg, 2.53 mmol) was added to this solution, followed by the addition of 4-methylmorpholine (0.30 mL, 2.7 mmol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (391 mg, 2.04 mmol), and the resulting mixture was stirred at room temperature for 16 hours. The reaction mixture was diluted with ethyl acetate, washed once with saturated aqueous ammonium chloride solution, once with saturated aqueous sodium bicarbonate solution, once with brine, dried (MgSO4), and concentrated. The crude product was purified by flash chromatography on silica gel, eluting with 40% ethyl acetate-hexanes, to give 1.17 g (91%) of 7 as a white solid. 1H-NMR (300 MHz, CDCl3): d 7.76 (d, J=7 Hz, 2H), 7.62-7.55 (m, 2H), 7.40 (t, J=7 Hz, 2H), 7.35-7.28 (m, 4H), 6.95-6.46 (m, 2H), 5.45-5.25 (m, 1H), 5.11-5.05 (m, 2H), 4.75-4.30 (m, 5H), 4.28-4.04 (m, 4H), 3.94-3.76 (m, 1H), 3.50-3.36 (m, 1H), 2.95-2.61 (m, 2H), 1.82-1.65 (m, 2H), 1.54-1.41 (m, 4H), 1.39-1.32 (m, 3H).

Provenance & Evidence