This invention relates to the compounds represented by a general formula [I]: ##STR1##

[in which A¹ and A² represent optionally fluorine-substituted methine or the like; B represents halogen, cyano, lower alkyl or the like; D represents optionally substituted heterocyclic group or the like; and G represents C₃-C₂₀ aliphatic group such as alicyclic group]. These compounds inhibit nociceptin activities due to their high affinity to nociceptin receptor, and are useful as analgesic, antiobestic, corebral function improver, drugs for treatment of alzheimer's disease and dementia, remedies for schizophrenia and neurodegenerative diseases, antidepressant, remedies for diabetes insipidus, polyuria, hypotension and so on.