The aim of the present invention is to provide cyclic aminomethylpyrimidine derivatives and pharmaceutically acceptable salts thereof which show high selectivity for dopamine D4 receptors and are useful for treating dieseases such as attention deficit hyperactivity disorder. The aim can be achieved by providing a compound representey by Formula (1): wherein n and m are indepedently 1 or 2 Ra is a C1-6 alkyl group, a C3-6 cycloalkyl group or an amino group Rb is a hydrogen atom, a C1-6 alkyl group or the like, provided that Rb is a hydrogen atom when Ra is an amino group Rc1 and Rc2 are indepedently a hydrogen atom or a C1-6 alkyl group Rd1 and Rd2 are indepedently a hydrogen atom, a fluorine atom or the like Ring Q is au optionally-substituted pyridyl group or an optionally-substituted isoquinolinyl group and a bond comprising a dashed line is a single bond or a double bond or a pharmaceutically acceptable salt thereof.本發明提供一種對多巴胺D4受體顯現選擇性較高之作用,而可用作注意缺陷過動性障礙等之治療劑之環狀胺基甲基嘧啶衍生物及其藥學上所容許之鹽。具體而言,提供一種化合物或其藥學上所容許之鹽,其由式(1)所表示。[式中,n及m分別獨立地表示1或2;Ra表示C1-6烷基、C3-6環烷基、或胺基;Rb表示氫原子、C1-6烷基等(其中,Ra為胺基時,Rb為氫原子);Rc1及Rc2分別獨立地表示氫原子、或C1-6烷基;Rd1及Rd2分別獨立地表示氫原子、氟原子等;環Q表示可經取代之吡啶基、或可經取代之異喹啉基;包含虛線之鍵表示單鍵或雙鍵。]
