NOVEL PYRAZINE DERIVATIVES OR SALTS THEREOF, PHARMACEUTICAL COMPOSITIONS CONTAINING THE DERIVATIVES OR THE SALTS AND INTERMEDIATES FOR THE PREPARATION OF BOTH

摘要

Pyrazine derivatives represented by general formula Ä1Ü: wherein the variables are as defined in the specification, or salts thereof have an excellent antiviral activity and are useful as a therapeutic agent for treating viral infections. Further, fluoropyrazine-carboxamide derivatives represented by general formula Ä2Ü: wherein the variables are as defined in the specification, or salts thereof are useful as an intermediate for production of the compounds of general formula Ä1Ü, and as an intermediate for production of the fluoropyrazine-carboxamide derivatives of which one typical example is 6-fluoro-3-hyroxy-2-pyrazine-carboxamide having an antiviral activity.