申请人:IHARA CHEMICAL INDUSTRY CO., LTD.
公开号:EP0990639A1
公开(公告)日:2000-04-05
The present invention aims at providing processes for production, from inexpensive raw materials of high commercial availability, of N-cyclopropylanilines which are an important intermediate in producing a quinolonecarboxylic acid having a cyclopropyl group at the 1-position, a fluorine atom at the 6-position and an alkyl group, an alkoxy group or a fluorine-substituted methoxy group at the 8-position (this quinolonecarboxylic acid is a useful synthetic antibacterial agent); and intermediates therefor.
The present invention provides a process for producing an N-cyclopropyl-3,4-difluoroaniline represented by the general formula (4):
which process comprises reacting, in the presence of an acid in an alcohol type solvent, a 3,4-difluoro-2-substituted-aniline represented by the general formula (1):
with a 1-alkoxy-1-trialkylsilyloxycyclopropane represented by the general formula (2):
to produce an N-alkoxycyclopropylaniline represented by the general formula (3):
and then reducing the N-alkoxycyclopropylaniline.
本发明的目的是提供利用商业供应量大的廉价原料生产N-环丙基苯胺的工艺,N-环丙基苯胺是生产喹啉羧酸的重要中间体,喹啉羧酸在1位上有一个环丙基,在6位上有一个氟原子,在8位上有一个烷基、一个烷氧基或一个氟取代的甲氧基(这种喹啉羧酸是一种有用的合成抗菌剂);并提供其中间体。
本发明提供了一种由通式(4)代表的 N-环丙基-3,4-二氟苯胺的生产工艺:
该工艺包括在有酸存在的情况下,在醇类溶剂中使通式 (1) 所代表的 3,4-二氟-2-取代-苯胺与 1-烷氧基-1-三苯胺反应:
与通式(2)代表的 1-烷氧基-1-三烷基硅氧基环丙烷反应,生成 N-烷氧基环丙烷:
生成通式(3)代表的 N-烷氧基环丙基苯胺:
然后还原 N-烷氧基环丙基苯胺。