The present invention relates to a compound represented by formula [I]:wherein: R1is hydrogen, halogen, lower alkyl or cyano； Ring A is an optionally substituted heterocyclic group； Ring B is an optionally substituted 3 to 6-membered monocyclic group； and Y is optionally substituted amino, optionally substituted cyclic amino, optionally substituted aliphatic 3 to 6-membered monocyclyloxy, optionally substituted lower alkyl or optionally substituted lower alkyl-O-, or a pharmaceutically acceptable salt thereof, and to their use as PDE10 inhibitor.本發明關於一種以式[I]代表的化合物：其中：R1為氫、鹵素、低碳烷基或氰基；環A為隨意地經取代之雜環基團；環B為隨意地經取代之3至6-員單環基團；及Y為隨意地經取代之胺基、隨意地經取代之環狀胺基、隨意地經取代之脂族3至6-員單環基氧基、隨意地經取代之低碳烷基或隨意地經取代之低碳烷基-O-，或其醫藥上可接受之鹽，以及關於其作為PDE10抑制劑之用途。
