| abstract |
A pyridazinone derivative represented by the following general formula I;n wherein R' represents hydrogen atom or alkyl group, R 2 represents hydrogen atom, alkyl group, alkoxy group or alkylthio group, R 3 represents hydrogen atom or alkyl aroua each of R 4 , R 5 and R 6 represents hydrogen atom, hydroxy group or alkoxy group independently, or two of R 4 , R 5 and R 5 may join together to form -0-CH 2 -O- or -O-CH 2 -CH 2 -O-, n represents an integer of 0 to 4 and the dotted line represents single bond or double bond, or a salt thereof. The above compound is useful as a cardiotonic. |