The synthesis of a novel class of 6-amino-5-hydroxy-pyridazin-3(2 H)-ones (3-oxo-2,3-dihydropyridazines) is described. These compounds also contain an ethoxycarbonyl moiety at the 4-position of the pyridazinone ring. They are prepared in good to moderate yields (30-72%) by the condensation of disubstituted amines with (alkylhydrazono)- or (arylhydrazono)(chloro)acetates followed by subsequent acylation
The invention is directed to pyridazinone compounds and pharmaceutical compositions containing such compounds that are useful in treating infections by hepatitis C virus.