反应详情

A Parr hydrogenator was charged with platinum (IV) oxide (PtO2) (0.3 g) and a solution of benzoic acid 4-benzyloxy-3-nitro-phenyl ester(5.23 g, 15 mmol) (which was obtained in Example 15) in methanol (80 mL) and CH2Cl2 (40 mL). This mixture was then hydrogenated at 5 psi of hydrogen at 0˜10° C. for 2 hours. The reaction mixture was filtered through a short pad of celite and concentrated. Recrystallization from CH2Cl2/hexanes gave the title compound as a white solid (3.80 g, 79%); 1H NMR (300 MHz, CDCl3) δ 5.09(s, 2 H), 6.57(dd, J=10.1, 2.7 Hz, 1 H), 7.10(d, J=2.7 Hz, 1 H), 7.30–7.50(m, 8 H), 7.55–7.65(m, 1 H), 8.15–8.25(m, 2 H); MS (ES) m/z: 320.0 (MH+, 100%); HRMS Calcd. for C20H18NO3(MH+): 320.1281. Found: 320.1278.

1. filtrationThe reaction mixture was filtered through a short pad of celite and
2. concentrationconcentrated
3. customRecrystallization from CH2Cl2/hexanes