[F:1][CH:2]([F:14])[O:3][C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1[O:10][CH:11]([F:13])[F:12].[N+:15]([O-])([OH:17])=[O:16].C(=O)(O)[O-].[K+]>C(Cl)Cl>[F:1][CH:2]([F:14])[O:3][C:4]1[CH:9]=[CH:8][C:7]([N+:15]([O-:17])=[O:16])=[CH:6][C:5]=1[O:10][CH:11]([F:13])[F:12]A solution of 15 g of 1,2-bis(difluoromethoxy)benzene and 15 ml of 100% strength nitric acid in 150 ml of methylene chloride is stirred for 7 h at room temperature. The solution is neutralized with potassium bicarbonate solution and the organic phase is separated off. After chromatography on silica gel with cyclohexane/ethyl acetate (4:1), 1,2-bis(difluoromethoxy)-4-nitrobenzene is obtained, which is hydrogenated and acetylated analogously to Example 5a to yield N-[3,4-bis(difluoromethoxy)phenyl]-acetamide of m.p. 81°-83° C. Further reaction analogously to Example 5 gives N-[4,5-bis(difluoromethoxy)-2-nitrophenyl]-acetamide of m.p. 65°-67° C., N-[4,5-bis(difluoromethoxy)-2-nitro]-aniline of m.p. 107°-109° C., 4,5-bis(difluoromethoxy)-1,2-phenylenediamine dihydrochloride and the title compound of m.p. 285°-287° C. (decomposition; from isopropanol).
読み込み中…