反应详情

To 1-(2,6-Difluorobenzyl)-2-(2,6-difluorophenyl)benzimidazole-4-carbonitrile (Example 105) (0.60 g, 1.57 mmol) dissolved in ethanol (15 mL) and triethylamine (0.5 mL) was added hydroxylamine (0.14 g, 130 M %). After 24 h at reflux, the reaction was concentrated. The residue was redissolved in CH2Cl2 and washed with NaHSO4(10% soln), NaHCO3 (sat. aq) and NaCl (sat. aq). The combined washings were dried (Na2SO4), filtered and concentrated. The crude product was purified by flash chromatography eluting with 4% methanol/CH2Cl2 and recrystallization from methanol, yielding white crystals of N-hydroxy 1-(2,6-difluorobenzyl)-2-(2,6-difluorophenyl)benzimidazole-4-carboxamidine (0.57 g, 1.37 mmol, 87% yield). M.p. 214-216° C. 1H NMR (200 MHz, CD2Cl2): δ 7.84 (dd, J=1.1, 7.7 Hz, 1H, H5), 7.57 (m, 1H, H4′), 7.54 (dd, J=1.1, 8.2 Hz, 1H, H7), 7.30 (dd, J=7.7, 8.2 Hz, 1H, H6), 7.28 (m, 1H, H4″), 7.11 (m, 2H, H3′,5′), 6.83 (m, 2H, H3″,5″), 6.61 (br, 2H, NH2), 5.39 (s, 2H, CH2PhF2).

1. temperatureAfter 24 h at reflux
2. concentrationthe reaction was concentrated
3. dissolutionThe residue was redissolved in CH2Cl2
4. washwashed with NaHSO4(10% soln), NaHCO3 (sat. aq) and NaCl (sat. aq)
5. dry with materialThe combined washings were dried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated
8. customThe crude product was purified by flash chromatography
9. washeluting with 4% methanol/CH2Cl2 and recrystallization from methanol