Bromine → 5-Bromo-2-(2,2,2-trifluoroethyl)-2-trifluoromethyl-1,3-benzodioxole

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Reaction Steps

54.4 g of 2-(2,2,2-trifluoroethyl)-2-trifluoromethyl-1,3-benzodioxole were dissolved in 300 ml of carbon tetrachloride, and 0.4 g of anhydrous iron(III) chloride was added. 32 g of bromine were then added dropwise at the reflux temperature and the mixture was subsequently stirred until the reaction was complete (monitoring by gas chromatography). The mixture was then allowed to cool, and was washed with 10% strength by weight aqueous sodium hydrogen sulphide solution and water, dried with magnesium sulphate and concentrated. The residue was distilled in vacuo. The yield was 58 g (83% of theory), and the boiling point was 80° C. under 14 mbar. The characteristic absorptions in the NMR spectra were as follows: 19F-NMR: -59.2 and -84.9 ppm. 1H-NMR: 3.02 ppm.

Provenance & Evidence