3-Heteroaryl-3,5-dihydro-4-oxo-4H-pyridazino[4,5-b]indole-1-acetamide derivatives, their preparation and their application in therapeutics

Abstract

The invention discloses and claims therapeutic uses of compounds of general formula (I) Wherein X, R 1 , R 2 and R 3 are as described herein. The invention further discloses processes for preparing them, and novel intermediates therefor.

1 . A method of treating Alzheimer's disease in a patient comprising administering to said patient an effective amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof: 
       
         
           
           
               
               
           
         
         in which 
         X represents a hydrogen or halogen atom, 
         R 1  represents a hydrogen atom or a (C 1 -C 4 )alkyl group, 
         R 2  and R 3  each independently of one another represent a hydrogen atom or a (C 1 -C 4 )alkyl group, or else R 2  and R 3 , together with the nitrogen atom bearing them, form a pyrrolidinyl, piperidinyl, morpholinyl or 4-(C 1 -C 4 )alkylpiperazinyl group, and 
         Het represents a heteroaromatic group of pyridinyl, quinolinyl, isoquinolinyl, pyrimidinyl, pyrazinyl or pyridazinyl type which may carry one or more halogen atoms and/or one or more (C 1 -C 4 ) alkyl and/or (C 1 -C 4 )alkoxy groups. 
       
     
     
         2 . The method according to  claim 1 , wherein X represents a halogen atom. 
     
     
         3 . The method according to  claim 1 , wherein R 1  represents a (C 1 -C 4 )alkyl. 
     
     
         4 . The method according to  claim 1 , wherein R 2  and R 3 , each independently of one another, represent a (C 1 -C 4 )alkyl group or else R 2  and R 3 , together with the nitrogen atom bearing them, form a pyrrolidinyl or 4-(C 1 -C 4 )alkylpiperazinyl group. 
     
     
         5 . The method according to  claim 1 , wherein Het represents a heteroaromatic group of pyridinyl type which may carry one or more halogen atoms and/or one or more (C 1 -C 4 )alkyl and/or (C 1 -C 4 )alkoxy groups. 
     
     
         6 . The method according to  claim 1 , wherein X represents a chlorine atom and R 1  represents a methyl group.