Aniline → 2-(4-Aminophenyl)-1,1,1,3,3,3-hexafluoropropan-2-ol

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Reaction Steps

Aniline (10.35 ml, 0.1 mol) and 250 mg of p-toluenesulfonic acid catalyst are placed in a two-necked flask surmounted by a condenser. Hexafluoroacetone trihydrate is added dropwise (15.8 ml, 1.1 eq.) and the bath (graphite) is brought to 180° C. for 14 h. The product AHFHP (4-(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)aniline) is obtained by recrystallization from a dichloromethane/hexane mixture, in the form of a white powder (yield 52%). 1 g of nitrosonium tetrafluoroborate (NOBF4) (8.56 mmol, 1.1 eq.) is then placed in a round-bottomed flask dried under argon and is dissolved with 10 ml of anhydrous acetonitrile ACN. The whole mixture is brought to −30° C. by means of an acetone-liquid nitrogen bath and then 7.78 mmol of the arylamine precursor, solubilized in the minimum amount of ACN (5 to 30 ml), are added dropwise. The mixture is allowed to return to ambient temperature, and the product is precipitated from 100 ml of cold ether, filtered off on a frit and washed with cold ether. The white powder obtained is recrystallized with an ACN/Et2O mixture and obtained with a yield of 64%.

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