PROBLEM TO BE SOLVED: To provide a selective inhibition of Bruton's tyrosine kinase (Btk).SOLUTION: This invention provides amino pyrimidine derivatives, such as N-(3-(5-((1 -Acryloylazetidin-3-yl)oxy)-6-aminopyrimidin-4-yl)-5-fluoro-2-methylphenyl)-4- cyclopropyl-2-fluorobenzamide, and a pharmaceutically acceptable salt thereof. The compounds are useful in the treatment of: autoimmune disorders, inflammatory diseases, allergic diseases, airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD), transplant rejection, cancers e.g. of hematopoietic origin or solid tumors.SELECTED DRAWING: None【課題】ブルトン型チロシンキナーゼ(Btk)の選択的阻害剤の提供。【解決手段】N-(3-(5-((1-アクリロイルアゼチジン-3-イル)オキシ)-6-アミノピリミジン-4-イル)-5-フルオロ-2-メチルフェニル)-4-シクロプロピル-2-フルオロベンズアミド等のアミノピリミジン誘導体および薬学的に許容されるその塩。該化合物は、自己免疫障害、炎症性疾患、アレルギー性疾患、喘息および慢性閉塞性肺疾患(COPD)などの気道疾患、移植拒絶反応、がん、例えば造血由来のがんまたは固形腫瘍の処置に有効となり得る。【選択図】なし