Catechol → 2-(1-Chloro-2,2,2-trifluoroethyl)-2-trifluoromethyl-1,3-benzodioxole

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Reaction Steps

110 g of pyrocatechol were dissolved in 1,500 ml of acetonitrile, and 200 g of triethylamine were added. 235 g of 2,3-dichloro-1,1,1,4,4,4-hexafluoro-2-butene were added dropwise at 75° C. to the mixture. Stirring was continued at 75° C. for 2 hours. 1,200 ml of the solvent were then distilled off in vacuo and the residue was taken up in 1,500 ml of water. The product was extracted with diethyl ether and the organic phase was washed twice with 10% strength by weight aqueous sodium hydroxide solution and once with water. After drying with magnesium sulphate the product was concentrated and subjected to fractional distillation in vacuo. The yield was 258 g (=84% of theory). The boiling point was 63° C. at 12 mbar. The NMR spectra showed the following characteristic absorptions: 19F-NMR: -66.8 and -79.7 ppm; 1H-NMR: 4.71 ppm.

Provenance & Evidence