公开(公告)号：EP1165520A1

公开(公告)日：2002-01-02

申请号：EP00912664.0

申请日：2000-03-30

申请人： BASF AKTIENGESELLSCHAFT

发明人： MERKLE, Hans, Rupert ,  HERBIG, Klaus ,  FRETSCHNER, Erich ,  FRÖHLICH, Helmut

IPC分类号： C07D237/22

CPC分类号： C07D237/22

摘要： The invention relates to a method for producing 4-amino-5-chloro-1-phenyl pyridazinone-(6) by reacting 4,5-dichloro-1-phenyl pyridazinone-(6) with aqueous ammonia in the presence of a catalyst. According to the invention, a catalyst is used which is soluble in the aqueous alkaline reaction medium but which is, however, essentially insoluble in the reaction mixture that is acidically regulated after the 4-amino-5-chloro-1-phenyl pyridazinone-(6) has been removed. The inventive method makes it possible, in a simple manner, to recover and reuse the catalyst.