<p>Disclosed is a homocysteine synthase inhibitor which is useful for the prevention or treatment of a disease associated with homocysteine synthase. Specifically disclosed is a compound represented by general formula (I) [wherein each symbol is as defined in the description], a pharmacologically acceptable salt of the compound, or a solvate of the compound or the pharmacologically acceptable salt, which can be used as the homocysteine synthase inhibitor.</p>
