PROBLEM TO BE SOLVED: To provide an effective anti-HCV agent having a novel chemical structure.SOLUTION: The present invention relates to a compound represented by formula (I) in the figure (where Ar is a substituted or unsubstituted aromatic group, and R is a substituted or unsubstituted hydrocarbon group, or a substituted or unsubstituted heterocyclic group), a salt thereof or a solvate thereof, and an anti-HCV agent comprising the compound.SELECTED DRAWING: None【課題】新規な化学構造を有する有効な抗HCV薬を提供する。【解決手段】 下記式(I):【化1】(式中、Arは置換又は無置換の芳香族基であり、Rは置換又は無置換の炭化水素基、又は置換又は無置換の複素環基である。)で示される化合物、その塩又はそれらの溶媒和物、及び前記化合物を含有する抗HCV薬。【選択図】なし