[F:1][C:2]1[C:7]([F:8])=[C:6]([O:9][CH3:10])[C:5]([F:11])=[C:4]([F:12])[C:3]=1[N+:13]([O-])=O.[Sn].Cl.[OH-].[Na+]>C(O)C.O>[F:1][C:2]1[C:7]([F:8])=[C:6]([O:9][CH3:10])[C:5]([F:11])=[C:4]([F:12])[C:3]=1[NH2:13]Then, 25 g of the 2,3,5,6-tetrafluoro-4-methoxynitrobenzene was added to a dispersion of 30.3 g of tin dispersed in 230 ml of 95% ethanol. Thereto was dropwise added 70 ml of concentrated hydrochloric acid with ice-cooling. The mixture was refluxed for 2 hours with heating. Then, the reaction mixture was poured into 1,000 ml of water. Thereto was added an aqueous sodium hydroxide solution until the water layer became alkaline. The organic layer was extracted with 500 ml of ether. The ether layer was washed with an aqueous sodium chloride solution and dried over MgSO4. The resulting solution was subjected to vacuum distillation to remove the ether. The residue was subjected to recrystallization from ligroin to obtain 6 g of 2,3,5,6-tetrafluoro-4-methoxyaniline (yield: 28%).
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