An antiviral compound for use in the treatment of negative-sense, single-stranded RNA [herein after ssRNA] virus infections different from the Influenza A and Influenza B virus infections wherein said antiviral compound is of general formula (I) ) [compound (A), herein after] or a pharmaceutically acceptable salt thereof wherein - R1 is selected from an alkyl group having 1 to 12 carbon atoms which is optionally substituted by a halogen atom or hydroxyl group, a cycloalkyl group having 3 to 12 carbon atoms which is optionally substituted by a halogen atom or hydroxyl group, an aryl group, an alkylaryl group, or a cycloheteroalkyl group having 3 to 12 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms optionally substituted by a halogen atom or hydroxyl group, a cycloalkyl group having 3 to 6 carbon atoms which is optionally substituted by a halogen atom or hydroxyl group, a phenyl, a benzyl, a morpholine, or an imidazolyl, more preferably an alkyl group having 1 to 4 carbon atoms, a cyclohexyl, a phenyl or a benzyl.
