Method for producing aminocarbazoles

Abstract

Disclosed is a method for producing an aminocarbazole by catalytically reducing a nitrocarbazole, wherein as a catalyst is used an active nickel-based catalyst prepared by contacting a nickel-based catalyst with an alkali and an iron compound under a hydrogen gas or inert gas atmosphere in an inert solvent, and according to the method of the present inventions decrease in reaction speed, decrease in yield of a product or the like depending upon the lot of the starting nitrocarbazoles can be prevented, and aminocarbazoles can be produced in a good yield constantly.

What is claimed is:  
     
         1 . A method for producing an aminocarbazole by catalytically reducing a nitrocarbazole, wherein an active nickel-based catalyst prepared by contacting a nickel-based catalyst with an alkali and an iron compound under a hydrogen gas or inert gas atmosphere in an inert solvent is used as a catalyst.  
     
     
         2 . The method according to    claim 1    wherein the active nickel-based catalyst is a catalyst prepared using the iron compound in the amount of from 0.1 to 0.6 times by weight based on the nickel-based catalyst in terms of metal.  
     
     
         3 . The method according to    claim 1    wherein the nitrocarbazole is a 1-nitro-9-lower alkyl-substituted carbazole and/or a 3-nitro-9-lower alkyl-substituted carbazole.  
     
     
         4 . The method according to    claim 1    wherein the alkali is selected from alkali metal bicarbonates, alkali metal carbonates , and alkali metal hydroxides.  
     
     
         5 . The method according to    claim 1    wherein the inert solvent is selected from water, lower alcohols, and mixtures thereof.  
     
     
         6 . The method according to    claim 1    wherein the amount of inert solvent is from about 5 to 100 times by weight based on the total weight of the nickel-based catalyst and the iron compound.  
     
     
         7 . The method according to    claim 1    wherein the pressure of the hydrogen gas or inert gas is from 0 to 19.6 MPa·G (gauge pressure).  
     
     
         8 . The method according to    claim 1    wherein the temperature at which the nickel-based catalyst is contacted with the alkali and the iron compound is from about 0 to 200° C.