| 摘要 |
PURPOSE: Provided are a process of preparing trifluoromethylanilines which is a simple way in good yields and purities in few reaction steps and in customary apparatus, and trifluoromethylanilines containing higher levels of 4-isomers than in the prior art. Problematic reagents such as sulphur tetrafluoride and costly reagents such as bromides or iodides need not be used. There are no special ecological problems. CONSTITUTION: The process for the preparation of trifluoromethylanilines of formula(1) wherein R1 is hydrogen, fluorine, chlorine, bromine, methyl, monochloromethyl, dichloromethyl, or formyl, and R2 is hydrogen, fluorine or chlorine, with the proviso that when R1 and R2 are both hydrogen, the amino group is para to the trifluoromethyl group, comprises (a) nitrating a benzotrichloride of formula(2) wherein R1 and R2 are each as defined for formula(I), thereby forming a nitrobenzotrichloride, (b) converting the trichloromethyl group of the nitrobenzotrichloride into a trifluoromethyl group by reaction with anhydrous hydrofluoric acid, thereby forming a nitrobenzotrifluoride, and (c) reducing the nitro groups of the nitrobenzotrifluoride to form a trifluoromethylaniline of formula(1).
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