To provide a compound retaining the principal therapeutic effect of sitaxentan and having an improved CYP inhibitory effect.A compound represented by formula (1-1) or (1-2), or a pharmacologically acceptable salt thereof: wherein R1 is a halogen atom, etc., R2 is a methyl group, etc., R3 is a C1-6 alkyl group, etc., and M is a group represented by: , etc.本發明目的係為了提供一種保留了西他生坦之主要治療作用並且具有改善的CYP抑制作用之化合物。本發明提供一種由化學式(1-1)或化學式(1-2)代表之化合物,或其藥理學上可接受的鹽:其中R1係一鹵素原子等等,R2係一個甲基等等,R3係一個C1-6烷基等等,並且M係一由以下代表之基團:等等。