4-Amino-6-(pyridinyl)-3(2H)-pyridazinones and their use as cardiotonics
AssigneeSterling Drug Inc.
InventorsGeorge Y. Lesher, William B. Dickinson, Baldev Singh
Life of this patent
Estimating the term…
Abstract
4-Amino-2-R-6-PY-3(2H)-pyridazinones (I) or salts thereof, which are useful as cardiotonics, where R is hydrogen, lower-alkyl or lower-hydroxyalkyl, and PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents are prepared by: (a) reaction of 2-R-6-PY-3(2H)-pyridazinone (II) with hydrazine; (b) conversion from 2,3-dihydro-2-R-3-oxo-6-PY-4-pyridazinecarboxamide (III); or, (c) conversion form 2,3-dihydro-2-R-3-oxo-6-PY-4-pyridazinecarboxylic acid hydrazide (IV). Also shown are: the use of I or salts as cardiotonic agents; and, the preparation of intermediates.
Claims13
A 4-Amino-2-R-6-PY-3(2H)-pyridazinone having the formula ##STR3## or pharmaceutically-acceptable acid-addition salt thereof, where PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents, and, R is hydrogen, lower-alkyl or lower-hydroxyalkyl.
4-Amino-6-(4-pyridinyl)-3(2H)-pyridazinone or pharmaceutically-acceptable acid-addition salt thereof.
4-Amino-2-methyl-6-(4-pyridinyl)-3(2H)-pyridazinone or pharmaceutically-acceptable acid-addition salt thereof.
A cardiotonic composition for increasing cardiac contractility, said composition comprising a pharmaceutically-acceptable inert carrier and, as the active component thereof, an effective amount of a cardiotonic 4-amino-2-R-6-PY-3(2H)-pyridazinone or pharmaceutically-acceptable acid-addition salt thereof, where R is hydrogen, lower-alkyl or lower-hydroxyalkyl, and, PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents.
The method for increasing cardiac contractility in a patient requiring such treatment which comprises administering orally or parenterally in a solid or liquid dosage form to such patient an effective amount of a cardiotonic 4-amino-2-R-6-PY-3(2H)-pyridazinone or pharmaceutically-acceptable acid-addition salt thereof, where R is hydrogen, lower-alkyl or lower-hydroxyalkyl, and, PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents.
Dependencies are inferred from the claim text.