2-R.sub.2 -3-R.sub.3 -6-PY-5-Q-3H-imidazo[4,5-b]pyridines (I) or 1-R.sub.1 -2-R.sub.2 -6-PY-5-Q-1H-imidazo[4,5-b]pyridines (IA) or pharmaceutically-acceptable acid-addition salts thereof, where Q and R.sub.2 are each hydrogen or lower-alkyl, R.sub.1 and R.sub.3 are each hydrogen, lower-alkyl, lower-hydroxyalkyl, 2,3-dihydroxypropyl, lower-alkoxyalkyl or Y-NB where Y is lower-alkylene having at least two carbon atoms between its connecting linkages and NB is di-(lower-alkyl)amino or 4-morpholinyl, at least one of R.sub.1 or R.sub.3 being hydrogen, and PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents, which are useful as cardiotonics, are prepared by reacting 2-R.sub.3 NH-3-R.sub.1 NH-5-PY-6-Q-pyridine (II) with a tri-(lower-alkyl) ortho-(lower-alkanoate). Also shown are: the use of I or IA or salts in cardiotonic compositions and a method for increasing cardiac contractility; and, the preparation of the intermediates II, as well as intermediates used to prepare II.
2-R.sub.2 -3-R.sub.3 -6-PY-5-Q-3H-
咪唑并[4,5-b]
吡啶(I)或1-R.sub.1 -2-R.sub.2 -6-PY-5-Q-
1H-咪唑并[4,5-b]
吡啶(IA)或其药用可接受的酸盐,其中Q和R.sub.2分别为
氢或低烷基,R.sub.1和R.sub.3分别为
氢、低烷基、低羟基烷基、2,3-二羟基丙基、低烷
氧基烷基或Y-NB,其中Y为至少在其连接链之间具有两个
碳原子的低烷基,NB为二(低烷基)
氨基或4-
吗啉基,R.sub.1或R.sub.3中至少一个为
氢,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,这些化合物可用作心力衰竭药物,通过将2-R.sub.3 N
H-3-R.sub.1 NH-5-PY-6-Q-
吡啶(II)与三(低烷基)邻-(低烷酸
酯)反应制备。还显示了:在心力衰竭药物组合物中使用I或IA或盐以及增加心脏收缩力的方法;以及用于制备II的
中间体II的制备,以及用于制备II的
中间体。