| 摘要 |
2-R-4,5-dihydro-4-R'-6-PY-3(2H)-pyridazinones (I) or salts thereof, which are useful as cardiotonics, where R is lower-alkyl, R' is hydrogen or lower-alkyl, and PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents, are prepared by reacting 4-oxo-4-PY-2-R'-butanenitrile with an N-R-hydrazine salt of a strong inorganic acid or organic sulfonic acid or by reacting a lower-alkyl 4-oxo-4-PY-2-R'-butanoate or lower-alkyl 4-(sN)-4-cyano-4-PY-2-R'-butanoate with N-R-hydrazine where BW is 4-morpholinyl, 1piperidinyl or l-pyrrolidinyl. Also shown are: a) cardiotonic compositions and a method for increasing cardiac contractility using said compounds or salts where R is lower-alkyl b) the use of I as intermediates in preparing the corresponding 2 R-4-R'-6-PY-3(2H)-pyridazinones; and, c) the preparation of said lower alkyl 4-(BN)-4-cyano-4-PY-2-R'-butanoates. |
