Abstract: Compounds represented by the following general formula: [wherein X1, X2, X3 and X4 each independently represent a single bond, C1-6 alkylene, etc.; A2 represents optionally substituted phenyl, etc.; A1 represents an optionally substituted 5- to 7-membered heterocyclic group containing —C(=Q1)- (wherein Q1 represents oxygen, sulfur or ?N—R11 (wherein R11 represents hydrogen or C1-6 alkyl)) and nitrogen, etc.; and Z1 represents piperidin-diyl, etc.], salts thereof and hydrates of the foregoing.

Abstract: Compounds represented by the following general formula: [wherein X1, X2, X3 and X4 each independently represent a single bond, C1-6 alkylene, etc.; A2 represents optionally substituted phenyl, etc.; A1 represents an optionally substituted 5- to 7-membered heterocyclic group containing —C(=Q1)- (wherein Q1 represents oxygen, sulfur or ?N—R11 (wherein R11 represents hydrogen or C1-6 alkyl)) and nitrogen, etc.; and Z1 represents piperidin-diyl, etc.], salts thereof and hydrates of the foregoing.

Abstract: Compounds represented by the following general formula: [wherein X1, X2, X3 and X4 each independently represent a single bond, C1-6 alkylene, etc.; A2 represents optionally substituted phenyl, etc.; A1 represents an optionally substituted 5- to 7-membered heterocyclic group containing —C(=Q1)- (wherein Q1 represents oxygen, sulfur or ?N—R11 (wherein R11 represents hydrogen or C1-6 alkyl)) and nitrogen, etc.; and Z1 represents piperidin-diyl, etc.], salts thereof and hydrates of the foregoing.

Abstract: The present invention provides compounds represented by the following formula: wherein X1, X2, X3 and X4 each independently represents a single bond, C1-6 alkylene, etc.; A2 represents optionally substituted phenyl, etc.; A1 represents an optionally substituted 5- to 7-membered heterocyclic group containing —C(?Q1)—, Q1 wherein represents oxygen, sulfur or ?N—R11, wherein R11 represents hydrogen or C1-6 alkyl etc.; and Z1 represents piperidin-diyl, ect, salts thereof and hydrates of the foregoing.

Abstract: Compounds represented by the following general formula: [wherein X1, X2, X3 and X4 each independently represent a single bond, C1-6 alkylene, etc.; A2 represents optionally substituted phenyl, etc.; A1 represents an optionally substituted 5- to 7-membered heterocyclic group containing —C(=Q1)- (wherein Q1 represents oxygen, sulfur or ?N—R11 (wherein R11 represents hydrogen or C1-6 alkyl)) and nitrogen, etc.; and Z1 represents piperidin-diyl, etc.], salts thereof and hydrates of the foregoing.

Abstract: The present invention provides a preventive or therapeutic agent for diabetes mellitus and diabetic complications, which is a new type based on an adenosine A2 receptor antagonist action. That is, it provides a novel condensed imidazole compound which has an adenosine A2 receptor antagonist action, is effective for preventing or treating diabetes mellitus and diabetic complications, and is represented by the formula (I); (wherein R1 represents e.g. an amino group which may be substituted with an alkyl group; R2 represents e.g. hydrogen atom, an alkyl group, a cycloalkyl group or an alkyl group, alkenyl group or alkynyl group which may be substituted with hydrox etc.; R3 represents e.g. an optionally substituted alkyl group, alkenyl group, alkynyl group, aryl group, heteroaryl group, pyridinone group, pyrimidinone group or piperadinone group; Ar represents e.g.

Abstract: Compounds represented by the following general formula: 1