反应详情

To a mixture of the methyl ester of Example 35j (0.1 g, 0.27 mmol), isobutyraldehyde (0.098 g, 1.35 mmol)), trifluoro acetic acid (0.27 mmol) and sodium cyanoborohydride (0.67 mmol) was added MeOH (15 mL) at 0-5° C. The reaction mixture was stirred overnight at room temperature, treated with chilled water, neutralized with 10% aqueous NaHCO3, extracted with EtOAc, concentrated and subjected to hydrolysis as described in Example 11 to obtain the title compound (Tet. Lett. 38, 5831-5834, (1997)). Yield: 64.74%; 1H NMR (DMSO-d6): δ 0.90 (d, 6H, 2CH3), 1.80 (m, 1H, CH), 2.60 (s, 3H, CH3), 2.90 (d, 2H, N—CH2), 5.10 (s, 2H, CH2), 6.70 (s, 2H, Ar), 8.10 (d, 2H, Ar); MS: m/e (EI+) 409 (M+).

1. extractionextracted with EtOAc
2. concentrationconcentrated
3. customsubjected to hydrolysis