PYRAZOLE DERIVATIVES

A compound represented by formula (I) or a salt thereof; wherein R and R , which may be the same or different, each represent a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group, an amino group, an alkylamino group, an aryl group or an alkyl group; R and R , which may be the same, or different, each represent a hydrogen atom, a halogen atom, an alkoxy group, an amino group, an alkylamino group, an aryl group or an alkyl group; R represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or an arylalkyl group; Q represents an amidino group, a cycloalkyl group, a phenyl group or amonocyclic heterocyclic group except a pyrimidinyl group bonded to the N atom at its 2-position; G represents a nitrogen-containing saturated heterocyclic structure represented by formula: wherein X represents a nitrogen atom or CH, in which the ring may have a keto group and may have one or more substituents; Z represents a phenyl or heterocyclic group which may have one or more substituents, in which two substituents on the phenyl or heterocyclic group may be connected to each other to form a ring to provide a condensed bicyclic structure as a whole; the substituent on Z and the substituent on G may be connected to each other to form a condensed tricyclic or tetracyclic structure as a whole, and an antitumor agent containing the compound or a salt thereof as an active ingredient.