反应详情

A solution of Example 219B (5 g, 15.7 mmol) in DMF (100 mL) was treated with N-iodosuccinimide (4.23 g, 18.8 mmol), stirred at ambient temperature for 2 hours, concentrated to half the original volume, and poured into 5% sodium thiosulfate (400 mL). The mixture was filtered and the filter cake was washed with water and dried. The solids were dissolved in dichloromethane (300 mL), treated with silica gel (80 g), and concentrated. The residue was transferred to a silica gel column (600 g) and chromatographed with ethyl acetate/heptane (1:6) to provide 5.2 g (75%) of the desired product. 1H NMR (CD2Cl2, 400 MHz) δ 7.95 (s, 1H), 7.33-7.29 (m, 4H), 7.12 (s, 1H), 7.10 (t, 1H), 7.02-6.99 (m, 4H), 4.76 (br s, 1H); 13C NMR (CD2Cl2, 400 MHz) δ 158.4, 156.8, 154.7, 154.4, 148.6, 138.4, 131.3, 131.2, 130.4, 124.4, 122.9, 120.0, 119,9, 118.8, 72.0.

1. concentrationconcentrated to half the original volume
2. additionpoured into 5% sodium thiosulfate (400 mL)
3. filtrationThe mixture was filtered
4. washthe filter cake was washed with water
5. customdried
6. dissolutionThe solids were dissolved in dichloromethane (300 mL)
7. additiontreated with silica gel (80 g)
8. concentrationconcentrated
9. customchromatographed with ethyl acetate/heptane (1:6)