Nitric Acid → 3-(Difluoromethoxy)-2,4,5-trifluoro-6-nitrobenzoic acid

Reaktionsgleichung

[N+:1]([O-:4])(O)=[O:2].O.[F:6][CH:7]([F:21])[O:8][C:9]1[C:10]([F:20])=[C:11]([CH:15]=[C:16]([F:19])[C:17]=1[F:18])[C:12]([OH:14])=[O:13]>S(=O)(=O)(O)O>[F:21][CH:7]([F:6])[O:8][C:9]1[C:10]([F:20])=[C:11]([C:15]([N+:1]([O-:4])=[O:2])=[C:16]([F:19])[C:17]=1[F:18])[C:12]([OH:14])=[O:13]

Komponenten

Versuchsvorschrift

20 ml of concentrated aqueous nitric acid (d=1.42) were added dropwise, whilst stirring and cooling with water, to a solution of 15.0 g (0.062 moles) of 3-difluoromethoxy-2,4,5-trifluorobenzoic acid [(XXV), X=X'=F] (prepared as described in Preparation 1, 2 or 3) in 40 ml of concentrated aqueous sulfuric acid, and the mixture was stirred at 60° C. for 7 hours. At the end of this time, it was allowed to stand to cool to room temperature, and then the reaction mixture was poured into ice-water, and extracted with diethyl ether. The extract was washed with a saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate; the solvent was then removed by evaporation under reduced pressure, to give 16.6 g of 3-difluoromethoxy-2,4,5-trifluoro-6-nitrobenzoic acid as a yellow powder, melting at 77°-80° C.