PROBLEM TO BE SOLVED: To provide compounds which directly inhibit inositol requiring enzyme 1 (IRE-1α activity) in vitro, prodrugs, and pharmaceutically acceptable salts thereof.SOLUTION: The present invention provides a compound represented by formula (A) [Rand Rare H or the like; Q-Q, together with the benzene ring to which they are attached, form a benzofused ring, where at least one of Q-Qis a heteroatom selected from N, O, and S.【課題】インビトロでイノシトール要求性酵素1(IRE-1α活性)を直接阻害する化合物、それらのプロドラッグ及び薬学的に許容可能な塩の提供。【解決手段】式(A)で表される化合物。[R3及びR4はH等;Q5~Q8はこれらが結合しているベンゼン環と一緒になってベンゾ縮合環を形成し、Q5~Q8のうち少なくとも1つは、N、S、及びOより選択されるヘテロ原子]【選択図】なし