Abstract: 2-[R.sub.1 NHN(R)]-3-Q'-5-PY-6-Q-pyridines or pharmaceutically-acceptable acid-addition salts thereof are useful as cardiotonic agents, where Q is hydrogen or lower-alkyl, PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents, Q' is hydrogen or halo, R is hydrogen, lower-alkyl or lower-hydroxyalkyl, and R.sub.1 is hydrogen or when R is other than hydrogen R.sub.1 is the same as R. These compounds are prepared by reacting a 2-halo-3-Q'-5-PY-6-Q-pyridine with R.sub.1 NHNHR where 2-halo is bromo or chloro. Also shown are: the use of said 2-[R.sub.1 NN(R)]-3-Q'-5-PY-6-Q-pyridines as cardiotonic agents; and, the intermediates, 2,3-dihalo-5-PY-6-Q-pyridines, and their preparation from 3-nitro-5-PY-6-Q-2(1H)-pyridinones.

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.

Abstract: N-Hydroxy-1-R.sub.1 -1,2-dihydro-2-oxo-5-PY-6-R-nicotinimidamides or pharmaceutically-acceptable acid-addition salts thereof, useful as cardiotonic agents, are prepared by reacting 1-R.sub.1 -1,2-dihydro-2-oxo-5-PY-6-R-nicotinonitriles with hydroxylamine and are converted by reaction with polyphosphoric acid to the corresponding cardiotonically useful 1-R.sub.1 -3-amino-5-PY-6-R-2(1H)-pyridinones, where R.sub.1 is hydrogen, lower-alkyl and lower-hydroxyalkyl, 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.

Abstract: 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.

Abstract: 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 or lower-hydroxyalkyl, 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-(BN)-4-cyano-4-PY-2-R'-butanoate with N-R-hydrazine where BN is 4-morpholinyl, 1-piperidinyl or 1-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.

Abstract: 5-(Py-Y)-1H-benzimidazol-2-ol or 5-(Py-Y)-1H-benzimidazole-2-thiol or lower-alkyl ethers or thioethers thereof or pharmaceutically-acceptable acid-addition salts thereof, useful as cardiotonics, are prepared by reacting 4-(Py-Y)-1,2-benzenediamine with urear or carbonyldiimidazole to produce 5-(Py-Y)-1H-benzimidazol-2-ol or with thiourea, an alkali metal lower-alkyl xanthate or thiocarbonyldiimidazole to produce 5-(Py-Y)-1H-benzimidazole-2-thiol and by reacting 5-(Py-Y)-1H-benzimidazole-2-thiol with a lower-alkylating agent to produce 2-(lower-alkylthio)-5-(Py-Y)-1H-benzimidazole. 2-(Lower-alkoxy)-5-(Py-Y)-1H-benzimidazole is prepared by reacting 4-(Py-Y)-1,2-benzenediamine with tetra-(lower-alkoxy)methane.

Abstract: 2-[R.sub.1 NHN(R)]-3-Q'-5-Py-6-Q-pyridines or pharmaceutically-acceptable acid-addition salts thereof are useful as cardiotonic agents, where Q is hydrogen or lower-alkyl, PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents, Q' is hydrogen or halo, R is hydrogen, lower-alkyl or lower-hydroxyalkyl, and R.sub.1 is hydrogen or when R is other than hydrogen R.sub.1 is the same as R. These compounds are prepared by reacting a 2-halo-3-Q'-5-PY-6-Q-pyridine with R.sub.1 NHNHR where 2-halo is bromo or chloro. Also shown are: the use of said 2-[R.sub.1 NN(R)]-3-Q'-5-PY-6-Q-pyridines as cardiotonic agents; and, the intermediates, 2,3-dihalo-5-PY-6-Q-pyridines, and their preparation from 3-nitro-5-PY-6-Q-2(1H)-pyridinones.

Abstract: 1-R.sub.1 -4- or 5-[4-pyridinyl-(CH.sub.2).sub.n ]-1H-indole-2,3-dione 3-Q derivatives, useful as cardiotonics, bronchodilators, anti-asthmatics, anti-allergics and anti-cholinergics, are prepared by cyclization of N-{3- or 4-[4-pyridinyl-(CH.sub.2).sub.n ]phenyl}glyoxalamide oxime with acid; reaction of the product thus obtained with a carbonyl reactive reagent to prepare a compound where Q is other than O; and reaction of a compound where Q is either O or other than O with a lower-alkyl, hydroxy-lower-alkyl or di-lower-alkylamino-lower-alkyl ester of a strong mineral acid or with a carbo-lower-alkoxy-lower-alkyl halide to prepare compounds where R.sub.1 is other than hydrogen.

Abstract: 1,3-Dihydro-3-R-5-PY-2H-imidazo[4,5-b]pyridin-2-ones or 2-thiones of pharmaceutically-acceptable acid-addition salts thereof, which are useful as cardiotonic agents, where R is hydrogen, lower-alkyl, lower-hydroxyalkyl, 2,3-dihydroxypropyl, lower-alkoxyalkyl or Y-NB where Y is lower-alkylene and NB is di-(lower-alkyl)amino or 4-morpholinyl, and PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents, are prepared by reacting a 3-amino-2-RNH-6-PY-pyridine with urea or carbonyldiimidazole to produce said -2-ones or with an alkali metal xanthate, thiourea or thiocarbonyldiimidazole to produce said -2-thiones. Also shown is the preparation of the intermediate 3-amino-2-RNH-6-PY-pyridines.

Abstract: Disclosed and claimed are a cardiac composition and a method for increasing cardiac contractility using an effective amount of a cardiotonic 4-[4-(or 3)-AcNH-phenyl]-2-R.sub.2 -3-R.sub.3 -5-R.sub.5 -6-R.sub.6 -pyridine (I) or pharmaceutically-acceptable salt thereof, where R.sub.2 is hydrogen, methyl, ethyl or hydroxyl, R.sub.6 is hydrogen, methyl or ethyl, R.sub.3 and R.sub.5 are each hydrogen or methyl, and Ac is hydrogen, hydroxyacetyl, acetoxyacetyl, .alpha.-hydroxypropionyl, .alpha.-acetoxypropionyl, methyoxyacetyl, 2-butenoyl or carbamyl or when NHAc is attached to the 4-position of the phenyl ring Ac also is formyl, n-propanoyl, 2,2-dimethyl-n-propanoyl or 3-carboxypropanoyl or when NHAc is attached to the 3-position of the phenyl ring Ac also is acetyl. Novel compounds shown and claimed are 4-[4-(or 3)-Ac'NH-phenyl]-2-R.sub.2 -3-R.sub.3 -5-R.sub.5 -6-R.sub.6 -pyridines (II) or pharmaceutically-acceptable acid-addition salts thereof, where R.sub.2, R.sub.3, R.sub.5 and R.sub.

Abstract: 1-R.sub.1 -3-[amino, cyano, carbamyl, halo, lower-alkylamino, di-(lower-alkyl)amino or lower-acylamino]-6-(lower-alkyl)-5-(pyridinyl)-2(1H)-pyridinones or pharmaceutically-acceptable acid-addition or cationic salts thereof are useful as cardiotonic agents, where R.sub.1 is hydrogen, lower-alkyl or lower-hydroxyalkyl. 1-R.sub.1 -3-amino-6-(lower-alkyl)-5-(pyridinyl)-2(1H)-pyridinones are prepared by hydrolyzing the corresponding 3-cyano compounds to produce the corresponding 3-carbamyl compounds and reacting the latter with a reagent capable of converting carbamyl to amino. The 1-R.sub.1 -3-cyano-6-(lower-alkyl)-5-(pyridinyl)-2(1H)-pyridinones are prepared by reacting (pyridinylmethyl) lower-alkyl ketones with dimethylformamide di-(lower-alkyl) acetal to produce 1-(pyridinyl)-2-(dimethylamino)ethenyl lower-alkyl ketone and reacting said ketones with N-R.sub.1 -.alpha.-cyanoacetamide to produce the 1-R.sub.1 -3-cyano-6-(lower-alkyl)-5-(pyridinyl)-2(1H)-pyridinones.

Abstract: 1-R.sub.1 -6-(lower-alkyl)-5-(pyridinyl)-2(1H)-pyridinones or 1-R.sub.1 -1,2-dihydro-2-oxo-6-(lower-alkyl)-5-(pyridinyl)nicotinic acids or lower-alkyl esters thereof or pharmaceutically-acceptable acid-addition or cationic salts thereof are useful as cardiotonic agents, where R.sub.1 is hydrogen, lower-alkyl or lower-hydroxyalkyl. These compounds are prepared by hydrolyzing the corresponding 3-cyano compounds to produce the corresponding 3-carboxylic acids and then either by decarboxylating or esterifying the acids.

Abstract: 5-PY-benzoxazol-2(3H)-ones, cardiotonic agents, are prepared by reacting 2-amino-4-PY-phenol with a carbonylating agent, e.g., carbonyldiimidazole, where PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents. 5-PY-benzoxazol-2(3H)-ones or pharmaceutically-acceptable acid-addition or cationic salts thereof are disclosed as active components in cardiotonic compositions for increasing cardiac contractility and in the method for increasing cardiac contractility in a patient requiring such treatment.

Abstract: 1,3-Dihydro-1-R.sub.1 -3-R.sub.3 -6-PY-5-Q-2H-imidazo[4,5-b]pyridin-2-ones or -2-thiones or pharmaceutically-acceptable acid-addition salts thereof, which are useful as cardiotonic agents, where Q is 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 and NB is di-(lower-alkyl)amino or 4-morpholinyl, at least one of R.sub.1 and R.sub.3 being hydrogen, and PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two substituents, are prepared by reacting a 2-R.sub.3 NH-3-R.sub.1 NH-5-PY-6-Q-pyridine with urea or carbonyldiimidazole to produce said -2-one or with an alkali metal xanthate, thiourea or thiocarbonyldiimidazole to produce said -2-thione. Also shown and claimed are cardiotonic compositions and a method for increasing cardiac contractility using said cardiotonic agents. Also shown are processes for preparing said intermediate 2-R.sub.3 NH-3-R.sub.

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.

Abstract: N-Hydroxy-1-R.sub.1 -1,2-dihydro-2-oxo-5-PY-6-R-nicotinimidamides or pharmaceutically-acceptable acid-addition salts thereof, useful as cardiotonic agents, are prepared by reacting 1-R.sub.1 -1,2-dihydro-2-oxo-5-PY-6-R-nicotinonitriles with hydroxylamine and are converted by reaction with polyphosphoric acid to the corresponding cardiotonically useful 1-R.sub.1 -3-amino-5-PY-6-R-2(1H)-pyridinones, where R.sub.1 is hydrogen, lower-alkyl and lower-hydroxyalkyl, 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.

Abstract: 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.

Abstract: 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 reacting 2-R-4,5-dihydro-6-PY-3(2H)-pyridazinone with a dehydrogenating agent. Also shown are: cardiotonic compositions and a method for increasing cardiac contractility using I or salts; and, the preparation of the corresponding intermediate 4,5-dihydro compounds.

Abstract: 3-Hydrazino-6-PY-pyridazine or pharmaceutically-acceptable acid-addition salt thereof is useful as a cardiotonic agent, where PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substitutents. 6-PY-3-pyridazinol is prepared by reacting 6-PY-3-pyridazinol with a chlorinating agent to produce 3-chloro-6-PY-pyridazine and reacting said 3-chloro compound with hydrazine to produce said 3-hydrazino compound. 3-Hydrazino-6-PY-pyridazine or pharmaceutically-acceptable acid-addition salt thereof is disclosed as the active component in cardiotonic compositions for increasing cardiac contractility and in the method for increasing cardiac contractility in a patient requiring such treatment. The novel intermediate 3-chloro-6-PY-pyridazine is prepared as noted above.

Abstract: 4(or 3)-(3,4-Dihydroxyphenyl)pyridine, a cardiotonic agent, is prepared by demethylating 4(or 3)-(3,4-dimethoxyphenyl)pyridine, preferably by heating with aqueous hydrogen bromide. 4(or3)-[3,4-di-(OR)-phenyl]pyridine, where R is hydrogen or methyl, or pharmaceutically-acceptable acid-addition salt thereof is disclosed as the active component in a cardiotonic composition for increasing cardiac contractility and in the method for increasing cardiac contractility in a patient requiring such treatment. The novel isomeric 2-[3,4-di-(OR)-phenyl]pyridine, where R is hydrogen or methyl, is shown for comparative purposes.