Hydroxypyridinones

A compound of formula I ##STR10## wherein:

• R.sub.1 is hydrogen, halogen, substituted or unsubstituted lower alkyl or lower alkoxy, lower alkoxycarbonyl, amino, substituted or unsubstituted lower alkylamino or di-lower alkylamino, aminocarbonyl, substituted or unsubstituted N-lower alkylaminocarbonyl or N,N-di-lower alkylaminocarbonyl, carboxyl, lower alkylsulfonyl, aminosulfonyl, cyano, hydroxy, nitro, tetrazolyl, or lower alkylenedioxy which with the group B forms a heterocyclic oxygen-containing ring system;
• R.sub.2 is hydrogen, substituted or unsubstituted lower alkyl or lower alkylenehydroxy, substituted or unsubstituted lower alkylene-lower alkoxy, lower alkylenecarboxy, lower alkylenecarbonyl-lower alkoxy, substituted or unsubstituted lower alkyleneamine, substituted or unsubstituted N-lower alkanoyl-lower alkyleneamine, lower alkanoyloxy-lower alkylene, formyl-lower alkylene;
• R.sub.3 is hydrogen, substituted or unsubstituted lower alkyl, substituted or unsubstituted lower alkanoyloxy-lower alkylene, aminocarbonyl, substituted or unsubstituted N-lower alkylaminocarbonyl, N,N-di-lower alkylaminocarbonyl;
• R.sub.4 is hydrogen, lower alkanoyl, lower alkoxycarbonyl, or a radical that can be removed under physiological conditions;
• A is substituted or unsubstituted methylene, carbonyl;
• and
• B is mono- or poly-substituted or unsubstituted aryl or mono- or poly-substituted or unsubstituted heteroaryl;
• or a stereoisomer, a tautomer or a salt thereof.