[Cl:1][C:2]1[CH:7]=[C:6]([F:8])[C:5]([NH:9][C:10](=[O:14])[O:11][CH2:12][CH3:13])=[C:4](F)[C:3]=1[N+:16]([O-:18])=[O:17].[CH3:19][OH:20]>O1CCOCC1>[Cl:1][C:2]1[CH:7]=[C:6]([F:8])[C:5]([NH:9][C:10](=[O:14])[O:11][CH2:12][CH3:13])=[C:4]([O:20][CH3:19])[C:3]=1[N+:16]([O-:18])=[O:17]Under a nitrogen atmosphere, a solution of 30.6 grams (0.109 mole) of ethyl N-(4-chloro-2,6-difluoro-3-nitrophenyl)carbamate and 18 mL (0.449 mole) of methanol in 175 mL of dioxane was stirred and 218 mL (0.218 mole) of 1 M sodium trimethylsilanoate (in tetrahydrofuran) was added dropwise during a 45 minute period. Upon completion of addition, the reaction mixture was heated to 65° C. where it stirred for three hours. At the conclusion of this period, the reaction mixture was allowed to cool to ambient temperature where it stirred for about 18 hours. The reaction mixture was concentrated under reduced pressure to a residue. The residue was taken up in cold 3 N hydrochloric acid. The resulting solid was collected by filtration, washed with petroleum ether, and heat dried under vacuum, yielding 21.3 grams of title compound. The NMR spectrum was consistent with the proposed structure.
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