2-ALKYL-6-(PYRAZOLOPYRIDIN-4-YL)PYRIDAZINONE DERIVATIVE, ADDITION SALT THEREOF, AND PDE INHIBITOR COMPRISING THE DERIVATIVE OR THE SALT AS ACTIVE INGREDIENT

摘要

[PROBLEMS] To provide a 2-alkyl-6-(pyrazolopyridin- 4-yl)pyridazinone derivative which is useful as a pharmaceutical agent having a phosphodiesterase-inhibiting activity. [MEANS FOR SOLVING PROBLEMS] A 2-alkyl-6- (pyrazolopyridin-4-yl)pyridazinone derivative represented by the general formula (1) (a specific example: 6-(7-methoxy-2- trifluoromethylpyrazolo[1,5-a]pyridin-4-yl)-5-methyl-2-[3- [4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3- yl)phenoxy]propyl]-4,5-dihydro-2H- pyridazin-3-one).