CC(C)([O-])C.[K+].Cl.CO[NH2:10].[Cl:11][C:12]1[CH:13]=[C:14]([C:18]([N+:21]([O-:23])=[O:22])=[CH:19][CH:20]=1)[C:15]([OH:17])=[O:16]>CN(C=O)C.O.C([O-])(=O)C.[Cu+2].C([O-])(=O)C>[NH2:10][C:19]1[C:18]([N+:21]([O-:23])=[O:22])=[C:14]([CH:13]=[C:12]([Cl:11])[CH:20]=1)[C:15]([OH:17])=[O:16]
To a mixture of potassium tert-butoxide (38.9 g, 0.347 mol) and copper-(II) acetate monohydrate (0.9 g, 4.96 mmol) in DMF (160 ml) was added a solution of O-methylhydroxylamine hydrochloride (8.3 g, 99.3 mmol) and 3-chloro-6-nitrobenzoic acid (69; 10 g, 49.6 mmol) in DMF (160 ml) at 0° C. The resulting reaction mixture was stirred at that temperature for 3 h. It was then quenched with water, acidified with 10% HCl and extracted with EtOAc. The combined organic layers were dried (Na2SO4) and concentrated under reduced pressure. The residue was taken up in EtOAc and extracted with 10% aqueous NaOH. The combined aqueous layers were acidified with concentrated HCl to a pH=3 and then extracted with EtOAc. The combined organic layers were dried (Na2SO4) and concentrated under reduced pressure to afford 3-amino-5-chloro-2-nitrobenzoic acid 70 (6.5 g, 60.5%) as a brown red solid.
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