反应详情

To a solution of Example 65A (415 mg, 2.14 mmol) in methanol (12 mL) was added methoxylamine hydrochloride (0.179 g, 2.14 mmol) and pyridine (0.87 mL, 10.8 mmol). The mixture was stirred overnight at room temperature and was then evaporated in vacuo. The residue was partitioned between ethyl acetate and H2O, and the organic layer was dried over Na2SO4 and was evaporated in vacuo. The residue thus obtained was dissolved in methanol (8 mL) and was hydrogenated (balloon) over 10% Pd-C in the presence of 4 drops of concentrated HCl overnight at room temperature. The catalyst was filtered off (Celite), and the filtrate was evaporated in vacuo. The residue was taken up in ether (20 mL) and was extracted with 1N HCl (3×10 mL). These acidic extracts were then basified to pH 10 with 2N NaOH and were extracted with ethyl acetate (3×10 mL). Drying over Na2SO4, followed by evaporation in vacuo, yielded Example 65B, 158 mg (48%). 1H NMR (300 MHz, DMSO-d6) δ ppm 7.56 (m, 1H), 6.66 (m, 1H), 6.48 (m, 1H), 3.81 (m, 1H), 2.02 (m, 2H), 1.35 (s, 3H), 1.20 (s, 3H). MS (ESI) m/z 196 (M+H).

1. customwas then evaporated in vacuo
2. customThe residue was partitioned between ethyl acetate and H2O
3. dry with materialthe organic layer was dried over Na2SO4
4. customwas evaporated in vacuo
5. customThe residue thus obtained
6. customat room temperature
7. filtrationThe catalyst was filtered off (Celite)
8. customthe filtrate was evaporated in vacuo
9. extractionwas extracted with 1N HCl (3×10 mL)
10. extractionwere extracted with ethyl acetate (3×10 mL)
11. dry with materialDrying over Na2SO4
12. customfollowed by evaporation in vacuo
13. customyielded Example 65B, 158 mg (48%)