Diisopropylethylamine → N2-({3-[(tert-butoxycarbonyl)amino] oxetan-3-yl}carbonyl)-N-{(3R,4S,5S)-3-methoxy-1-[(2S)-2-{(1R,2R)-1-methoxy-2-methyl-3-oxo-3-[(2-phenylethyl)amino]propyl}pyrrolidin-1-yl]-5-methyl-1-oxoheptan-4-yl}-N-methyl-L-valinamide

Participants

Reaction Steps

To #73 (100 mg, 0.174 mmol, 1 eq.) in dichloromethane (4 mL, 0.04) and N,N-dimethylformamide (0.5 mL) was added #71 (45.2 mg, 0.208 mmol, 1.2 eq.), followed by diisopropylethylamine (92 μL, 0.521 mmol, 3 eq.) and HATU (102 mg, 0.260 mmol, 1.5 eq.). After 16 hours, the reaction was concentrated in vacuo and the residue was taken up in ethyl acetate (6 mL) and washed with 1 M aqueous hydrochloric acid solution (2×2 mL) and with brine. The organic layer was dried over sodium sulfate, filtered, and concentrated in vacuo. The crude material was purified by reverse phase chromatography (Method C) to give #74 (140 mg), which was used in the next step without further purification. LC-MS: m/z 774.7 [M+H+], 796.6 [M+Na+], retention time=0.91 minute.

Provenance & Evidence