反应详情

To 1-(2,6-difluorobenzyl)-2-(2-fluoro-4-methoxylphenyl)-4-nitrobenzimidazole (Example 50) (2.00 g, 4.98 mmol) dissolved in acetic acid (20 mL) was added SnCl2x2H2O (9.02 g) dissolved in concentrated HCl (8 mL). After stirring for 30 min at room temperature, the mixture was concentrated. The residue was diluted with CH2Cl2 and washed with NaHCO3 (sat. aq.) and NaCl (sat. aq.). The combined washings were dried (Na2SO4), filtered, and evaporated. The crude product was recrystallized from methanol to give 3.26 g of white crystals, (8.78 mmol, 70% yield). M.p. 200-202° C. 1H-NMR (200 MHz, CD2Cl2) δ7.45 (m, 1H, H4′), 7.22 (m, 1H, H4″), 7.05 (dd, J=7.8, 7.6 Hz, 1H, H6), 6.85-6.72 (m, 5H, H3″,5″), 6.50 (dd, J=7.7, 1.0 Hz, 1H, H5), 5.21 (d, J=5.4 Hz, 2H, CH2PhF2 (rotamers)), 4.34 (br, 2H, NH2), 3.72 (s, 3H, OCH3).

1. additionwas added SnCl2x2H2O (9.02 g)
2. concentrationthe mixture was concentrated
3. additionThe residue was diluted with CH2Cl2
4. washwashed with NaHCO3 (sat. aq.) and NaCl (sat. aq.)
5. dry with materialThe combined washings were dried (Na2SO4)
6. filtrationfiltered
7. customevaporated
8. customThe crude product was recrystallized from methanol