C([O:8][C:9]1[C:14]([F:15])=[C:13]([F:16])[C:12]([N+:17]([O-:19])=[O:18])=[C:11]([O:20][CH2:21][CH:22]=[CH2:23])[C:10]=1[F:24])C1C=CC=CC=1>FC(F)(F)C(O)=O>[CH2:21]([O:20][C:11]1[C:10]([F:24])=[C:9]([OH:8])[C:14]([F:15])=[C:13]([F:16])[C:12]=1[N+:17]([O-:19])=[O:18])[CH:22]=[CH2:23]33.9 g of the 1-benzyloxy-3-(prop-2-enyloxy)-4-nitro-2,5,6-trifluorobenzene prepared as described in Example 5 (0.1 mol) are dissolved in 120 ml of trifluoroacetic acid in a three-neck flask fitted with reflux condenser and stirrer, and the mixture is then refluxed for 4 hours. The reaction solution is then allowed to cool to room temperature, and the crude product is extracted by shaking with 200 ml of ethyl acetate and 300 ml of water. The organic phase is washed three times with water, dried over sodium sulfate and evaporated to half in a rotary evaporator. The precipitated reaction product is then recrystallized from a mixture of n-hexane and methylene chloride (volume ratio 1:1) and then dried for 48 hours under nitrogen at 40° C./10 mbar in a vacuum drying cabinet.
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