Abstract: N-R.sub.1 -N-(6-R-5-PY-2-pyridinyl)ureas, where R.sub.1 is lower-alkyl, 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, or acid-addition salts thereof. Said compounds (I) or pharmaceutically acceptable acid-addition salts thereof are useful as cardiotonic agents. The preparation and cardiotonic use of said compounds are shown.

Abstract: 2-Q-6-Q'-8-R-pyrido[2,3-d]pyrimidin-5(8H)-ones (I), where Q is 4(or 3)-hydroxyphenyl, 4(or 3)-methoxyphenyl, 4(or 3)-pyridinyl or 4(or 3)-pyridinyl having one or two lower-alkyl substituents, R' is hydrogen or alkyl having one to four carbon atoms, Q is hydrogen, amino or nitro, and R is alkyl having from one to four carbon atoms, CH(C.sub.2 H.sub.5).sub.2, (CH.sub.2).sub.n .dbd.CHCH.sub.2 where n is 1 or 2, or Y-Z where Y is alkylene having from two to four carbon atoms and having its connecting linkages on different carbon atoms and Z is hydroxy, OR.sub.1 or NR.sub.1 R.sub.2 where R.sub.1 and R.sub.2 are each methyl or ethyl, or acid-addition salts thereof, and their preparation are shown. Also shown is the cardiotonic use of I where Q is 4(or 3)-hydroxyphenyl, 4(or 3)-pyridinyl or 4(or 3)-pyridinyl having one or two lower-alkyl substituents and Q' is hydrogen or amino.

Abstract: 3,4-Dihydro-3-R.sub.1 -4-R.sub.2 -5-Q-6-R-2(1H)-pyridinones (I), where R.sub.1 and R.sub.2 are each hydrogen or methyl, R is lower-alkyl, and Q is 4(or 3)-hydroxyphenyl, 4(or 3)-methoxyphenyl, 4(or 3)-pyridinyl or 4(or 3)-pyridinyl having one or two lower-alkyl substituents, or acid-addition salts thereof, and their preparation are shown. Also shown is the cardiotonic use of I where Q is 4(or 3)-hydroxyphenyl, 4(or 3)-pyridinyl or 4(or 3)-pyridinyl having one or two lower-alkyl substituents.

Abstract: 5-PY-6-Q-pyridin-2-amines (I) or pharmaceutically acceptable acid-addition salts thereof are useful cardiotonics, where Q is hydrogen or lower-alkyl, and PY is 4-pyridinyl or 4-pyridinyl having one or two lower-alkyl substituents. Their preparation from the corresponding 5-PY-6-Q-2(1H-pyridinones via the corresponding 2-halo-5-PY-6-Q-pyridines is shown.

Abstract: 3-Methyl-4-(4-pyridinyl)benzeneamines, useful as cardiotonic agents, are prepared by reaction of pyridine, benzoyl chloride and an appropriate 3-methyl-N,N-di-lower-alkylbenzeneamine in the presence of copper powder and decomposing the reaction mixture with alkali and, if desired, reacting a resulting 3-methyl-4-(4-pyridinyl)-N,N-di-lower-alkylbenzeneamine with hydrogen bromide and pyridine to obtain 3-methyl-4-(4-pyridinyl)benzeneamine.

Abstract: 1-R"-3-Q-4-R'-5-R-1,6-naphthyridin-2(1H)-ones (I) or salts thereof, where R is lower-alkyl, R' is hydrogen or methyl, R" is hydrogen or lower-alkyl, and Q is hydrogen, hydroxy, amino, cyano, carbamyl, carboxy or aminocarbamyl, are useful as cardiotonic agents (I, Q is hydrogen, hydroxy, amino, cyano or carbamyl) and/or intermediates therefor (I, Q is carboxy, aminocarbamyl, hydrogen, amino, cyano or carbamyl). Also shown are 3-Q"-4-R'-5-(RCO)-6-[2-(di-lower-alkylamino)ethenyl]-2(1H)-pyridinones (II) or salts thereof, where R and R' are as above and Q' is hydrogen or cyano, which are useful as cardiotonics (II, Q' is hydrogen) and/or intermediates (II, Q' is cyano or hydrogen). Processes for preparing the compounds of formulas I and II are shown.

Abstract: 4-R.sub.2 -5-(Lower-alkanoyl)-6-(lower-alkyl)-2(1H)-pyridinones (I), useful as cardiotonics, where R.sub.2 is hydrogen or methyl, are prepared by reacting 2-(lower-alkanoyl)-1-(lower-alkyl)ethenamine (II) with lower-alkyl 2-propynoate or 2-butynoate respectively or by hydrolyzing 4-R.sub.2 -5-(lower-alkanoyl)-6-(lower-alkyl)-1,2-dihydro-2-oxonicotinonitrile (III, Q is CN) or corresponding 4-R.sub.2 -5-(lower-alkanoyl)-6-(lower-alkyl)-1,2-dihydro-2-oxonicotinamide to produce the corresponding 5-(lower-alkanoyl)-6-(lower-alkyl)-1,2-dihydro-2-oxonicotinic acid and decarboxylating said substituted nictotinic acid to produce I. Also disclosed and claimed are cardiotonic uses of 3-Q-4-R.sub.2 -5-(lower-alkanoyl)-6-(lower-alkyl)-2(1H)-pyridinones where Q is hydrogen or cyano and R.sub.2 is hydrogen or methyl (III). Also shown and claimed is methyl 4-acetyl-5-amino-2,4-hexadienoate or acid-addition salt thereof, useful as intermediate or cardiotonic.

Abstract: 2-(NB)-3-R-6-PY-5-Q-3H-imidazo[4,5-b]pyridines (I) and salts, useful as cardiotonics, where NB is amino or dimethylamino, R is lower-alkyl, Q 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 a 2-RNH-3-amino-5-PY-6-Q-pyridine with a di-(lower-alkyl) 2-methylthiopseudourea-1,3-dicarboxylate to produce 2-carbo(lower-alkoxy)amino-3-R-6-PY-5-Q-3H-imidazo[4,5-b] pyridine and hydrolyzing the latter to produce I where NB is amino and by reacting a 2-RNH-3-amino-5-PY-6-Q-pyridine with dichloromethylene-N,N-dimethylammonium chloride to produce I where NB is dimethylamino. Cardiotonic use of I is disclosed and claimed.

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: Disclosed and claimed are N-R-N-40 [4-(4-2-R.sub.2 -3-R.sub.3 -5-R.sub.5 -6-R.sub.6 -4-pyridinyl)phenyl]ureas (I) or pharmaceutically-acceptable acid-addition salts thereof, where R is hydrogen, methyl or ethyl, R.sub.2 is hydrogen, methyl, ethyl or hydroxyl, R.sub.6 hydrogen, methyl or ethyl, and R.sub.3 and R.sub.5 are each hydrogen or methyl, their cardiotonic use and their preparation.

Abstract: 1-R-3-R'-5-PY-1H-pyrazolo[3,4-b] pyridines (I) or acid-addition salts thereof, which are useful as cardiotonics, are prepared by reacting a .alpha.-PY-.beta.dimethylamino-acrolein with 5-amino-1-R-3-R'-1H-pyrazole, 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. Also shown are cardiotonic compositions and method for increasing cardiac contractility using said compounds (I) or pharmaceutically acceptable acid-addition salts thereof.

Abstract: Shown is a process for preparing cardiotonically active 1,3-dihydro-3-R-6-PY-5-Q-2H-imidazo[4,5-b]pyridin-2-ones, where Q is hydrogen or lower-alkyl, R is lower-alkyl, lower-hydroxyalkyl, 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 substituents, by reacting a 2-RNH-5-PY-6-Q-nicotinamide with an alkali metal hypohalite. Also shown are cardiotonic compositions and a method for increasing cardiac contractility using 2-RR'N-5-PY-6-Q-nicotinamides or pharmaceutically acceptable acid-addition salts thereof, where R' is hydrogen or methyl. Also shown is the process for preparing said 2-RR'N-5-PY-6-Q-nicotinamides by reacting a 2-halo-5-PY-6-Q-nicotinamide with an amine of the formula RR'NH.

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-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 -o-cyanoacetamide to produce the 1-R.sub.1 -3-cyano-6-(lower-alkyl)-5-(pyridinyl)-2(1H)-pyridinones.

Abstract: 1-R.sub.1 -1,2-dihydro-6-[2-(dimethylamino)ethenyl]-2-oxo-5-PY-nicotinonitriles, where R.sub.1 is hydrogen or methyl, and PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents, or pharmaceutically acceptable acid-addition salts thereof are useful as cardiotonic agents. Said compounds are prepared by reacting 1,2-dihydro-6-methyl-2-oxo-5-PY-nicotinonitrile with dimethylformamide dimethylacetal. Shown is the cardiotonic use of said compounds or pharmaceutically acceptable acid-addition salts thereof.

Abstract: 1-R.sub.1 -3-[(1-Methyl-3-oxo-1-butenyl)amino or (3-oxo-1-butenyl)amino]-5-PY-6-R-2(1H)-pyridinones, where R.sub.1 is hydrogen or lower-alkyl, PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents and R is hydrogen or lower-alkyl, or pharmaceutically acceptable acid-addition salts thereof are useful as cardiotonic agents. The preparation and cardiotonic use of said compounds are shown.

Abstract: Shown are cardiotonically active 2-RR'N-5-PY-6-Q-nicotinonitriles where R is methyl or ethyl, R' is hydrogen or methyl, PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two substituents, and Q is hydrogen or methyl, the latter only when R' is hydrogen, or pharmaceutically acceptable acid-addition salts thereof. Also shown are cardiotonic compositions and a method for increasing cardiac contractility using as active components 2-RR'N-5-PY-6-Q-nicotinonitriles or pharmaceutically acceptable acid-addition salts thereof, where R, R', PY and Q are defined as above. Also shown is the process for preparing said 2-RR'N-5-PY-6-Q-nicotinonitriles by reacting a 2-halo-5-PY-6-Q-nicotinonitrile with an amine of the formula RR'NH.

Abstract: 3-(Hydroxy or hydroxymethyl)-6-methyl-5-(4-pyridinyl)-2(1H)-pyridinone or pharmaceutically acceptable acid-addition salt thereof is useful as a cardiotonic agent. 3-Hydroxy-6-methyl-5-(4-pyridinyl)-2(1H)-pyridinone is prepared by autoclaving a mixture of a sodium or potassium lower-alkoxide, a lower-alkanol and 3-(chloro or bromo)-6-methyl-5-(4-pyridinyl)-2(1H)-pyridinone and acidifying the reaction mixture. 3-Hydroxymethyl-6-methyl-5-(4-pyridinyl)-2(1H)-pyridinone is prepared by reacting 6-methyl-5-(4-pyridinyl)-2(1H)-pyridinone with excess formaldehyde at an acidic pH. Said 3-(hydroxy or hydroxymethyl)-6-methyl-5-(4-pyridinyl)-2(1H)-pyridinone or pharmaceutically acceptable acid-addition salt thereof is disclosed as the active ingredient in cardiotonic compositions for increasing cardiac contractility and in the method for increasing cardiac contractility in a patient requiring such treatment.

Abstract: 1-R-3-(NB)-5-PY-6-Q-1H-pyrazolo[3,4-b]pyridines or pharmaceutically-acceptable acid-addition salts thereof, which are useful as cardiotonics, are prepared by reacting a 1-R-5-PY-6-Q-1H-pyrazolo[3,4-b]pyridin-3-amine with a lower-alkanoic acid and reducing agent to produce 1-R-3-(NB)-5-PY-6-Q-1H-pyrazolo[3,4-b]pyridine (I) where NB is NHR.sub.1 or NR.sub.1 R.sub.2, with a mixture of formic acid and formaldehyde to produce I where NB is N(CH.sub.3).sub.2 or with a lower-acylating agent to produce I where NB is NHAc and, if desired, reacting the 3-(NHAc) compound with a reducing agent to prepare the corresponding 3-NHR.sub.1 compound, where R is lower-alkyl, lower-hydroxyalkyl, lower-acyloxy-(lower-alkyl) or lower-alkoxy-alkyl, Q is hydrogen or lower-alkyl, PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents, and NB is selected from NHR.sub.1, NR.sub.1 R.sub.2 or NHAc where R.sub.1 and R.sub.2 are each lower-alkyl and Ac is lower-acyl.

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 substituents. 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.