To provide a novel 2,6-diaminopyrimidine derivative by the following formula (I):A 2,6-diaminopyrimidine derivative is represented by the formula (I):whereinR1 represents a substituted or unsubstituted lower alkyl group, or a substituted or unsubstituted alkoxy group,Ar represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group,Z1 and Z2 represent carbon atoms, or either 1 or 2 of the Z1 and Z2 represent nitrogen atoms,Q is selected from a structure (a) or (b) described below:R2 represents a substituted or unsubstituted lower alkyl group, or a substituted or unsubstituted cycloalkyl group,R3 represents a hydrogen atom or a halogen atom,Y represents a nitrogen atom or a carbon atom, andthe bond drawn with a dotted line parallel to a solid line on structure (a) represents either double bond or single bond.
