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: 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: 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: 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: 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: 1,2-Dihydro-1-R-5-PY-6-Q-3H-pyrazolo[3,4-b]pyridin-3-ones or pharmaceutically-acceptable acid-addition salts thereof, which are useful as cardiotonic agents, are prepared by reacting lower-alkyl 2-halo-5-PY-6-Q-nicotinate with 1-R-hydrazine. Also disclosed are cardiotonic compositions and method for increasing cardiotonic contractility using said compounds or salts.

Abstract: 1-R-5-PY-6-Q-1H-pyrazolo[3,4-b]pyridin-3-amines or pharmaceutically-acceptable acid-addition salts thereof, which are useful as cardiotonics, are prepared by reacting a 2-halo-5-PY-6-Q-nicotinonitrile with 1-R-hydrazine, where R is hydrogen, lower-alkyl, lower-hydroxyalkyl, 2,3-dihydroxypropyl or lower-alkoxyalkyl, 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. Also shown are cardiotonic compositions and method for increasing cardiac contractility using said compounds or salts.

Abstract: Cardiotonic composition and method for increasing cardiac contractility using an effective amount of a cardiotonic lower-alkyl 2-halo-5-PY-6-Q'-nicotinate or pharmaceutically-acceptable acid-addition salt thereof, where halo is chloro or bromo, 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. Also shown are novel lower-alkyl 2-halo-5-PY-6-(lower-alkyl)nicotinates or pharmaceutically-acceptable acid-addition salt thereof, useful as intermediates or cardiotonics and preparation thereof.