REDUCTION OF CF₃-GROUP IN POLYFLUOROBENZENETRIFLUORIDES

S.Igumnov, K.Merkulov, E.Igunmova, R.Nefedova, V.Don

It is known that CF₃-group in benzotrifluorides can be reduced HSiEt₃ in the presence of AlCI₃ [1]. It is fixed that various aliphatic and cyclic hydrocarbons under the same conditions can be hydrogen donors.
Thus depending on the reaction conditions and ratio of reagents during reduction of polyfluorotoluenes the corresponding benzalchlorides, benzylchlorides and toluenes were synthesized.

Thus in the reaction of octafluorotoluene with two moles AlCl₃ with plenty of cyclohexane in dichloroethane mixture of products I, II, III in ratio 7:3:90 in the total yield around 60% is formed.

In the reaction of octafluorotoluene with 1,5 moles A1C13 with plenty of pentane mixture of I, II H III in ratio 5 5:3 5:10 in the total yield 70% is formed.

The above method opens the new posibilities of synthesis of substituted polyfluorinated toluenes.

1) M.E.Volpin, N.V. Schevchenko, G.I. Bolestova, Yu.A. Fialkov, Z.N.Pames. Mendeleev Commun. 1991 N. 118-119.