[N+:1]([C:4]1[CH:8]=[CH:7][N:6]([CH:9]2[CH2:12][N:11]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:10]2)[N:5]=1)([O-])=O>C(O)C>[NH2:1][C:4]1[CH:8]=[CH:7][N:6]([CH:9]2[CH2:10][N:11]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:12]2)[N:5]=1A 500-mL Parr reactor bottle was purged with nitrogen and charged with 10% palladium on carbon (50% wet, 100 mg dry weight) and a solution of 105a (1.91 g, 7.23 mmol) in ethanol (25 mL). The bottle was attached to a Parr hydrogenator, evacuated, charged with hydrogen gas to a pressure of 50 psi and shaken for 4 h. After this time, the hydrogen was evacuated, and nitrogen was charged into the bottle. Celite 521 (5 g) was added, and the mixture was filtered through a pad of Celite 521. The filter cake was washed with ethanol (2×25 mL), and the combined filtrates were concentrated to dryness under reduced pressure to afford a 100% yield of 105b (1.76 g) as a light yellow oil: 1H NMR (500 MHz, CDCl3) δ 7.22 (d, 1H, J=2.5 Hz), 5.61 (d, 1H, J=2.5 Hz), 4.80 (quant, 1H, J=7.0 Hz), 4.25 (d, 4H, J=7.0 Hz), 3.77 (br s, 2H), 1.41 (s, 9H).
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