Nitrogen-containing heterocyclic carboxamide derivatives or salts thereof and antiviral agents comprising the same

摘要

Nitrogen-containing heterocyclic carboxamide derivatives represented by the following general formula:wherein ring A is a substituted or unsubstituted pyrazine, pyrimidine, pyridazine or triazine ring; R<1 >is O or OH; R<2 >is a hydrogen atom, an acyl group or a substituted or unsubstituted carbamoylalkyl or carboxyalkyl group; and the broken line represents a single bond or a double bond; or salts thereof are useful for preventing and treating virus infections and especially influenza virus infections.