Catechol → 2-(2,2,2-Trifluoroethyl)-2-(trifluoromethyl)-1,3-benzodioxole

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Reaction Steps

11 g of pyrocatechol were dissolved in 200 ml of dimethylformamide and the solution was treated with 18 g of 45% strength by weight aqueous sodium hydroxide solution. The mixture was treated dropwise at 75° C. with 20 g of 2-chloro-1,1,1,4,4,4-hexafluoro-2-butene. Stirring was continued for 30 minutes at 75° C. The batch was subsequently poured into 500 ml of ice-water and extracted using diethyl ether. The organic phase was washed with water, dried with magnesium sulphate and concentrated. Finally, the product was distilled under a high vacuum. The yield was 15 g (=56%), and the boiling point 60° C. at 10 mbar. The NMR spectra showed the following characteristic absorptions: 19F-NMR: -59.0 and -84.6 ppm. 1H-NMR: 3.02 ppm.

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