A compound represented by the following formula (1) or a salt thereof: wherein R1 represents hydrogen atom, a halogen atom and the like; R2 represents hydrogen atom, a halogen atom, a C1-6 alkyl group and the like; and R3 represents —O—X—C(A1)(A11)-C(A2)(A21)-N(A31)(A3) (X represents propylene group etc., A11 and A21 represent hydrogen atom, or a C1-6 alkyl group, A31 represents a C1-6 alkyl group substituted with hydroxyl group, or hydrogen atom, and A1, A2, and A3 represent hydrogen atom, a C1-6 alkyl group and the like) and the like, which has an inhibitory activity on the phosphorylation of myosin regulatory light chain, and is useful for treatment of diseases relating to contraction of various cells and the like.