Reaction Steps
According to general procedure D, from #77 (399 mg, ≦0.52 mmol, 1 eq.), N-[(9H-fluoren-9-ylmethoxy)carbonyl]-N,2-dimethylalanine (213 mg, 0.628 mmol, 1.2 eq.), dichloromethane (5 mL, 0.1 M), HATU (239 mg, 0.628 mmol, 1.2 eq.) and diisopropylethylamine (282 μL, 1.62 mmol, 3.1 eq.) was synthesized the crude desired material, which was purified by silica gel chromatography (Gradient: 0% to 50% acetone in heptane), providing #78 (231 mg, 46% over two steps). LC-MS: m/z 970.7 [M+H+], 992.6 [M+Na+], retention time=1.11 minutes; HPLC (Protocol C): retention time=9.260 minutes; 1H NMR (400 MHz, DMSO-d6), presumed to be a mixture of rotamers, characteristic signals: δ [10.19 (d, J=7.4 Hz) and 10.47 (d, J=7.8 Hz), total 1H], 7.89 (d, J=7.4 Hz, 2H), 7.61-7.67 (m, 2H), 7.41 (br dd, J=7.4, 7.4 Hz, 2H), 7.14-7.36 (m, 8H), [5.20 (ddd, J=11, 7, 5 Hz) and 5.38 (ddd, J=11, 8, 4 Hz), total 1H], [4.41 (dd, J=8.6, 8.4 Hz) and 4.46 (dd, J=8.2, 8.2 Hz), total 1H], 3.65 and 3.68 (2 s, total 3H), 3.23 and 3.24 (2 s, total 3H), 3.13 (br s, 3H), 2.88 and 2.93 (2 br s, total 3H), 2.84 and 2.85 (2 s, total 3H), 1.31 and 1.32 (2 s, total 3H), [1.15 (d, J=6.6 Hz) and 1.18 (d, J=6.4 Hz), total 3H].
