Preparation of Trifluoromethylanilines

• Main Authors: BAUMANN KAETHE, MARHOLD ALBRECHT
• Format: Patent
• Language: English; Korean
• Published: 06.07.2001
• Edition: 7
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; APPARATUS THEREFOR; CHEMISTRY; GENERAL METHODS OF ORGANIC CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

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). 트리플루오로메틸아닐린은 벤조트리클로라이드를 니트로화하고, 이렇게 얻어질 수 있는 니트로벤조트리클로라이드에서의 트리클로로메틸기를 무수 플루오르화수소산과 반응시켜 트리플루오로메틸기로 전환시키고, 마지막으로 니트로기를 환원시키는 유리한 방법으로 얻어진다.