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.
4-
氨基-2-R-6-PY-3(2H)-
吡啶嗪酮(I)或其盐,可用作心脏强心剂,其中R为氢,低烷基或低羟基烷基,PY为4-或3-
吡啶基或带有一个或两个低烷基取代基的4-或3-
吡啶基,通过以下方法制备:(a)2-R-6-PY-3(2H)-
吡啶嗪酮(II)与
肼反应;(b)由2,3-二氢-2-R-3-氧代-6-PY-4-
吡啶嗪羧酰胺(III)转化而来;或(c)由2,3-二氢-2-R-3-氧代-6-PY-4-
吡啶嗪
羧酸肼(IV)转化而来。还显示了:将I或其盐用作心脏强心剂的用途;以及中间体的制备。