[Cl:1][C:2]([Cl:7])([Cl:6])[C:3](Cl)=[O:4].[Cl:8][C:9]1[C:10]([F:21])=[C:11]([CH:18]=[CH:19][CH:20]=1)/[CH:12]=[CH:13]/[C:14](=[N:16]O)[NH2:15].N1C=CC=CC=1>C(Cl)(Cl)Cl>[Cl:8][C:9]1[C:10]([F:21])=[C:11]([CH:18]=[CH:19][CH:20]=1)/[CH:12]=[CH:13]/[C:14]1[N:16]=[C:3]([C:2]([Cl:7])([Cl:6])[Cl:1])[O:4][N:15]=112.7 g (0.07 mol) of trichloroacetyl chloride are added dropwise to a suspension consisting of 6.4 g (0.03 mol) of (E)-3-chloro-2-fluoro-cinnamamide oxime in 90 ml of chloroform and 6 ml (0.07 mol) of dry pyridine. During this process, there is a slight evolution of heat. Subsequently, the mixture is stirred for 1 hour and the pyridine hydrochloride which separates out is filtered off and washed with chloroform. The filtrate is concentrated in vacuo and the remaining solid material is recrystallized. 5.0 g (48.7% of theory) of (E)-3-(3-chloro-2-fluoro-styryl)-5-trichloromethyl-1,2,4-oxadiazole are obtained.
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