Patent ID: 7008940

Claim:
A compound represented by the formula: wherein A ring denotes a non-aromatic 5-membered nitrogen-containing heterocyclic ring of at least one nitrogen atom and carbon atoms and may have a further substituent selected from the group consisting of: an optionally substituted hydrocarbon group, an optionally halogenated lower alkoxy group, an optionally halogenated lower alkylthio group, a halogen atom, an aryloxy group, a lower alkanoyl group, an arylcarbonyl group, a lower alkanoyloxy group, an arylcarbonyloxy group, a carboxyl group, a lower alkoxy-carbonyl group, a carbamoyl group, a thiocarbamoyl group, a mono-lower alkylcarbamoyl group, a di-lower alkylcarbamoyl group, a C 6-10 aryl-carbamoyl group, an amidino group, an imino group, an amino group, a mono-lower alkylamino group, a di-lower alkylamino group, a 3- to 6-membered cyclic amino group optionally containing 1 to 3 heteroatoms selected from the group consisting of oxygen atom, sulfur atom and nitrogen atom, in addition to carbon atoms and one nitrogen atom, an alkylenedioxy group, a hydroxy group, a nitro group, a cyano group, a mercapto group, a sulfo group, a sulfino group, a phosphono group, a sulfamoyl group, a mono-lower alkylsulfamoyl group, a di-lower alkylsulfamoyl group, an arylthio group, a lower alkylsulfinyl group, an arylsulfinyl group, a lower alkylsulfonyl group, and an aryl sulfonyl group; B ring denotes a benzene ring which may be further substituted; C ring denotes a dihydrofuran ring which may be further substituted; and R denotes hydrogen atom or an acyl group; or a salt thereof.