1,6-Naphthyridin derivatives useful as cardiotonics and preparation thereof.

摘要

4-R min -5-Q-1,6-naphthyridin-2(1H)-ones (1), where R min is hydrogen or methyl and Q is hydroxymethyl, 1-hydroxyethyl alkanoyloxymethyl or 1-alkanoyloxyethyl, are produced by first reacting 4-R min -5-acetyl (or n-propanoyl)-6[2-(dilower-alkylamino]-2(1H)-pyridinone (III) with hydroxylamine or salt thereof to produce 4-R min -5-Q min -1,6-naphthyridin-2(1H)-one-6-oxide (II), where R min is defined as above and Q min is methyl or ethyl; next reacting II with an alkanoic anhydride to produce I where Q is alkanoyloxymethyl or 1-alkanoyloxyethyl; and, then hydrolyzing said alkanoyloxymethyl or -ethyl compound to produce I where Q is hydroxymethyl or 1-hydroxyethyl. Also shown is the cardiotonic use of II and I where Q is hydroxymethyl, 1-hydroxyethyl or alkanoyloxymethyl.