Disclosed is a compound represented by the general formula (1) or a salt thereof. The compound or the salt thereof has an inhibitory activity on IKKss and is therefore useful as a prophylactic and/or therapeutic agent for a disease associated with IKKss. In the formula, R represents a hydrogen atom, a lower alkyl group, an aryl group, a hydroxy group, or the like; R represents a halogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, or the like; and m represents a number of 0, 1, 2 or the like.