The invention of the present application provides a compound represented by formula (I) or a salt thereof, which exhibits an inhibitory activity against at least one kinase selected from the group consisting of Akt kinase, Rsk kinase and S6K kinase and/or a cell proliferation inhibiting effect and is useful as a prophylactic and/or therapeutic agent for diseases associated with the above-mentioned kinases, particularly cancer.[In the formula, R1 represents a 4- to 6-membered monocyclic unsaturated heterocyclic group which has 1 to 3 hetero atoms independently selected from N, S and O and may have a substituent R2 represents a hydrogen atom or the like R3, R4 and R5 may be the same as or different from one another and independently represent a hydrogen atom or the like R6 represents a hydrogen atom or the like R7 and R8 may be the same as or different from each other and independently represent a hydrogen atom or the like X1 and X2 may be the same as or different from each other and independently represent N or CR9 R9 represents a hydrogen atom or the like and X3 represents N or CH when the broken line (---) represents a single bond, and represents C when the broken line represents a double bond wherein at least one of X1 and X2 represents N.]La présente invention concerne un composé de formule (I) ou un sel correspondant, qui présente une activité inhibitrice vis-à-vis dau moins une kinase choisie dans le groupe constitué par lAkt kinase, la Rsk kinase et la S6K kinase et/ou un effet inhibiteur de la prolifération cellulaire, et qui est utilisé en tant quagent prophylactique et/ou thérapeutique pour des maladies associées aux kinases précitées, en particulier le cancer. [Dans la formule, R1 représente un groupe monocyclique insaturé hétérocyclique de 4 à 6 éléments qui comporte de 1 à 3 hétéroatomes indépendamment choisis parmi N, S et O et peut comporter un substituent R2 représente un atome dhydrogène ou semblable R3, R4 et R5 peuvent être identiques ou différen
