[OH:1][C:2]1[C:12]([N+:13]([O-])=O)=[CH:11][CH:10]=[CH:9][C:3]=1[C:4]([N:6]([CH3:8])[CH3:7])=[O:5].O.NN>CCO.CC(O)=O.O.CCOC(C)=O>[NH2:13][C:12]1[C:2]([OH:1])=[C:3]([CH:9]=[CH:10][CH:11]=1)[C:4]([N:6]([CH3:8])[CH3:7])=[O:5]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.
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