(R)-7-(丁-2-炔-1-基)-8-(3-羟基哌啶-1-基)-3-甲基-1-((4-甲基喹唑啉-2-基)甲基)-1H--嘌呤-2,6(3H,7H)-二酮（利格列汀杂质），97%

(R)-7-(But-2-yn-1-yl)-8-(3-hydroxypiperidin-1-yl)-3-methyl-1-((4-methylquinazolin-2-yl)methyl)-1H-purine-2,6(3H,7H)-dione (Linagliptin Impurity)