反应详情

67.5 g of 2-Hydroxy-N,N-dimethyl-3-nitro-benzamide are dissolved in 1000 ml of EtOH/AcOH 9/1 and degassed 4× by evacuating and purging with argon. 7.5 g of Ru/C are added and the mixture obtained is degassed 4× by evacuating and purging with argon. A reaction mixture obtained is heated to reflux and 25 ml of hydrazine hydrate are added slowly. At 1 hour intervals 3 further portions of 25 ml of hydrazine hydrate are added. A reaction mixture obtained is cooled to rt, filtered and washed with EtOH. Solvent from the filtrate obtained is evaporated. Toluene is added 4× to the residue obtained and solvent is evaporated. A residue obtained is taken up in 1 l of H2O and 1 l of EtOAc. An aqueous layer obtained is extracted 3× with EtOAc. The organic layers obtained are washed 2× with brine, dried, filtered and solvent is evaporated. A residue obtained is purified by column chromatography over 500 g of silica using EtOAc/heptane 1/1 as the eluant to give 3-amino-2-hydroxy-N,N-dimethyl-benzamide.

1. customdegassed 4×
2. customby evacuating
3. custompurging with argon
4. addition7.5 g of Ru/C are added
5. customthe mixture obtained
6. customis degassed 4×
7. customby evacuating
8. custompurging with argon
9. customA reaction mixture obtained
10. temperatureis heated
11. temperatureto reflux
12. customA reaction mixture obtained
13. filtrationfiltered
14. washwashed with EtOH
15. customSolvent from the filtrate obtained
16. customis evaporated
17. additionToluene is added 4× to the residue
18. customobtained
19. customsolvent is evaporated
20. customA residue obtained
21. customAn aqueous layer obtained
22. extractionis extracted 3× with EtOAc
23. customThe organic layers obtained
24. washare washed 2× with brine
25. customdried
26. filtrationfiltered
27. customsolvent is evaporated
28. customA residue obtained
29. customis purified by column chromatography over 500 g of silica