Abstract 595890 Disclosed is a compound having an inhibitory activity on the secretion of an acid and exhibiting an anti-tumor activity and others. Specifically disclosed is a compound represented by formula (I) wherein R1 represents a substituent； R2 represents a hydrogen atom, a C1-6 alkyl group which may have a halogen atom, or a cyano group； and R3 represents a hydrogen atom, a halogen atom, a cyano group, a C1-6 alkyl group which may have a halogen atom, or a C1-6 alkoxy group which may have a halogen atom； wherein one of R2 and R3 represents a hydrogen atom and the other represents a substituent other than a hydrogen atom] or a salt thereof.
