Reaction Steps
To (S)-2-amino-3-(3,4-dimethoxyphenyl)-N-((S)-1-((S)-2-methyloxiran-2-yl)-1-oxo-3-phenylpropan-2-yl)propanamide TFA salt (784 mg, 1.54 mmol) in DMF (5 mL) was added potassium (S)-2-(2-morpholinoacetamido)propanoate (470 mg, 1.85 mmol), HATU (702 mg, 1.85 mmol), DIEA (1.02 mL, 6.16 mmol). The mixture was allowed to stir for 15 min at which time it was quenched with sodium bicarbonate (sat.), extracted with ethyl acetate (2×), dried with sodium sulfate, filtered, and concentrated. Purification by column chromatography (3:1 DCM/ethyl acetate+0-10% methanol) followed by trituration from ethyl acetate/heptane (1:1) provided (S)-3-(3,4-dimethoxyphenyl)-N-((S)-1-((S)-2-methyloxiran-2-yl)-1-oxo-3-phenylpropan-2-yl)-2-((R)-2-(2-morpholinoacetamido)propanamido)propanamide (322 mg, 34%) as a colorless amorphous solid. 1H NMR (400 MHz, CDCl3) δ 7.41 (d, J=7.7 Hz, 1H), 7.26-7.20 (m, 2H), 6.99 (dd, J=7.5, 1.8 Hz, 2H), 6.86-6.68 (m, 3H), 6.64 (d, J=7.3 Hz, 1H), 6.16 (d, J=7.0 Hz, 1H), 4.78-4.64 (m, 1H), 4.48 (q, J=7.1, 7.1, 7.0 Hz, 1H), 4.42-4.28 (m, 1H), 3.86 (d, J=4.0 Hz, 6H), 3.69 (t, J=4.6, 4.6 Hz, 4H), 3.27 (d, J=5.0 Hz, 1H), 3.08 (dd, J=14.0, 4.9 Hz, 1H), 3.02-2.79 (m, 5H), 2.64 (dd, J=14.0, 8.3 Hz, 1H), 2.45 (q, J=4.0, 3.9, 3.9 Hz, 4H), 1.49 (s, 2H), 1.30 (d, J=7.1 Hz, 3H). MS (EI) for C32H42N4O8, found 611.3 (MH+).
