2-R-4-R'-6-PY-3(2H)-pyridazinones (I) or salts thereof, which are useful as intermediates and some as cardiotonics, are prepared by reacting di-(lower-alkyl) hydroxy[2-oxo-2-PY-ethyl]propanedioate (II) with a hydrazine salt of the formula RNHNH.sub.2.nH.sub.x An (III) to produce lower-alkyl 2,3-dihydro-2-R-3-oxo-6-PY-4-pyridazinecarboxylate (Ia where R' is lower-carbalkoxy) and reacting Ia with hydrazine hydrate or anhydrous hydrazine to produce 2,3-dihydro-2-R-3-oxo-6-PY-4-pyridazinecarboxylic acid hydrazide (Ib where R' is aminocarbamyl), where PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents, R is hydrogen, lower-alkyl or lower-hydroxyalkyl, R' is carbamyl, carboxy, aminocarbamyl or lower-carbalkoxy, n is 1 or 2, x is 1, 2 or 3, and An is an anion of a strong inorganic acid or an organic sulfonic acid. Also shown are: the preparation of II from PY--COCH.sub.3 (IV), the conversion of Ia to Ib (Id where R' is carboxy), and the use of 2-R-4-R"-6-PY-3(2H)-pyridazinones (I where R is lower-alkyl or lower-hydroxyalkyl and R" is carbamyl, aminocarbamyl or lower-carbalkoxy) as cardiotonic agents. Other intermediates are shown.
2-R-4-R'-6-PY-3(2H)-
吡啶并
咪唑酮(I)或其盐,可作为中间体和一些作为心脏强心剂,通过将二(较低烷基)羟基[2-氧代-2-PY-乙基]
丙二酸酯(II)与公式RNHNH.sub.2.nH.sub.x An(III)的
肼盐反应制备,以产生较低烷基2,3-二氢-2-R-3-氧代-6-PY-4-
吡啶并
咪唑羧酸酯(Ia,其中R'为较低碳烷氧基),并将Ia与
肼水合物或无
水肼反应,以产生2,3-二氢-2-R-3-氧代-6-PY-4-
吡啶并
咪唑羧酸肼(Ib,其中R'为
氨基羰基),其中PY为4-或3-
吡啶基或带有一个或两个较低烷基取代基的4-或3-
吡啶基,R为氢、较低烷基或较低羟基烷基,R'为羰基、羧基、
氨基羰基或较低碳烷氧基,n为1或2,x为1、2或3,An为强
无机酸或有机
磺酸的阴离子。还显示了:从PY--COCH.sub.3(IV)制备II,将Ia转化为Ib(其中R'为羧基),以及将2-R-4-R"-6-PY-3(2H)-
吡啶并
咪唑酮(I,其中R为较低烷基或较低羟基烷基,R"为羰基、
氨基羰基或较低碳烷氧基)用作心脏强心剂。还显示了其他中间体。