Diisopropylethylamine → methyl N-{(2R,3R)-3-[(2S)-1-{(3R,4S,5S)-4-[(N-{[(2S)-1-(tert-butoxycarbonyl)-2-methylpiperidin-2-yl]carbonyl}-L-valyl)(methyl)amino]-3-methoxy-5-methylheptanoyl}pyrrolidin-2-yl]-3-methoxy-2-methylpropanoyl}-L-phenylalaninate

Participants

Reaction Steps

To a solution of #156 (106 mg, 0.436 mmol, 1 eq.) in dichloromethane (3 mL) and N,N-dimethylformamide (0.5 mL) was added diisopropylethylamine (0.228 mL, 1.31 mmol, 3 eq.) followed by HATU (205 mg, 0.523 mmol, 1.2 eq.). The reaction was stirred for 15 minutes and #114 (276 mg, 0.436 mmol, 1 eq.) was added and stirred at room temperature for 2 hours. The reaction was diluted with dichloromethane (10 mL) and washed with 10% citric acid (3×5 mL). The organic layer was dried over sodium sulfate, filtered and the filtrate concentrated in vacuo. Purification of the residue by silica gel chromatography (Gradient: 0 to 80% acetone in heptane) afforded #160 (145 mg, 39%). LC-MS (protocol Q1): m/z 858.8 [M+H+], retention time=1.12 minutes.

Provenance & Evidence