申请人:Bayer Aktiengesellschaft
公开号:US06333434B1
公开(公告)日:2001-12-25
The invention relates to a process for the preparation of trifluoromethylanilines of formula (I)
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, comprising
(a) nitrating a benzotrichloride of formula (II)
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 (I).
本发明涉及一种制备式(I)的三氟甲基苯胺的方法,其中R1为氢、氟、氯、溴、甲基、单氯甲基、二氯甲基或甲酰基,R2为氢、氟或氯,但当R1和R2均为氢时,氨基团位于三氟甲基团的对位,包括以下步骤:
(a) 硝化式(II)的苯并三氯甲烷,其中R1和R2如式(I)所定义,从而形成硝基苯并三氯甲烷,
(b) 通过与无水氢氟酸反应将硝基苯并三氯甲烷的三氯甲基基团转化为三氟甲基基团,从而形成硝基苯并三氟甲烷,
(c) 还原硝基苯并三氟甲烷的硝基团,以形成式(I)的三氟甲基苯胺。