5-(Pyridinyl)-1H-pyrazolo[3,4-b]pyridin-3-amines and their cardiotonic use

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. Also shown are cardiotonic compositions and method for increasing cardiac contractility using said compounds or salts.

Dependencies are inferred from the claim text.