3-heteroaryl-3,5-dihydro-4-oxo-4h-pyridazino[4,5-b]indole-1-carboxamide derivatives, their preparation and therapeutic use

A method for the treatment of a pathology in which the peripheral benzodiazepine receptors are involved which comprises administering to a patient in need of said treatment a therapeutically effective amount of a compound of formula (I):

• wherein:
• X represents a hydrogen or halogen atom,
• R1 represents a hydrogen atom or a (C1-C4)alkyl group;
• R2 and R3 each represent, independently of one another, a hydrogen atom or a (C1-C4)alkyl group or else R2 and R3 form, with the nitrogen atom which carries them, a pyrrolidinyl, piperidinyl, morpholinyl or 4-alkylpiperazinyl group;
• and
• Het represents a heteroaryl group selected from pyridinyl, 1-oxidopyridinyl, quinolinyl, isoquinolinyl, pyrimidinyl, pyrazinyl and pyridazinyl, optionally substituted with one or more halogen atoms,(C1-C4)alkyl or (C1-C4)alkoxy groups;
• or
• a hydrate or a pharmaceutically acceptable salt thereof;
• and
• wherein said pathology is selected from the group consisting of motor neuron condition, neurodegenerative disease of the central nervous system, sleep disorder, pathologies associated with the heart valves, inflammatory heart disease, side effects due to cardiotoxic medicaments or as a result of heart surgery, atherosclerosis and its thromboembolic complications, restenosis, conditions related to incorrect proliferation or incorrect migration of smooth muscle cells, cancer, cutaneous stress, and chronic inflammatory disease.