反应详情

To a solution of 2,5-dichloro-N-(2-hydroxyimino-ethyl)-benzamide (0.72 g, 2.9 mmol) in MeOH (20 mL) under an argon atmosphere at 0° C. was added methyl orange (trace) followed by a saturated solution of MeOH/HCl until a persistent red color was observed. Sodium cyanoborohydride (0.22 g, 3.5 mmol) was dissolved in MeOH (5 mL) and was added sequentially with saturated MeOH/HCl over 0.5 h. The reaction mixture was stirred an additional 1 h and the MeOH was removed in vacuo. The residue was basidified with saturated Na2CO3 and extracted (7×25 mL) with dichloromethane/MeOH (9:1). The combined organic extracts were washed with brine, were dried (Na2SO4) and were concentrated. The residue was purified by flash chromatography (2%-5% MeOH/dichloromethane) to provide the title compound (0.29 g, 40%) as a white solid. 1H NMR (400 MHz, CD3OD): δ 7.53 (s, 1H); 7.44 (s, 2H); 3.56 (t, j=6.2 Hz, 2H); 3.06 (t, j=6.2 Hz, 2H). ESMS: M+H=249.

1. customthe MeOH was removed in vacuo
2. extractionextracted (7×25 mL) with dichloromethane/MeOH (9:1)
3. washThe combined organic extracts were washed with brine
4. dry with materialwere dried (Na2SO4)
5. concentrationwere concentrated
6. customThe residue was purified by flash chromatography (2%-5% MeOH/dichloromethane)