The present invention relates to a compound represented by the followingformula (1):(see formula 1)wherein D1, A1, D2, R1, D3, and R2 each have the same meaning as defined inthe present specification or a saltthereof. The compound represented by the formula (1) or a salt thereof has anIKK.beta. inhibiting activity and the likeand is useful for the prevention and/or treatment of IKK.beta.-associateddiseases or symptoms and the like.