A compound represented by formula (1) or pharmaceutically acceptable salt thereof: wherein R 1 is a C 1-6 alkyl group; R 2 and R 3 are the same or different from each other and each is a hydrogen atom or a C 1-6 alkyl group; X 2 , X 3 and X 4 are the same or different from each other and each is a hydrogen atom or a halogen atom; and X 5 is a hydrogen atom or - P(=O)(OH) 2 has a Wnt Pathway modulating activity.