Linagliptin Dimer Impurity 2

Chemical Name: 8-((R)-3-aminopiperidin-1-yl)-1-((4-((2-((8-((R)-3-aminopiperidin-1-yl)-7-(but-2-yn-1-yl)-3-methyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)methyl)-4-methyl-1,4-dihydroquinazolin-4-yl)methyl)quinazolin-2-yl)methyl)-7-(but-2-yn-1-yl)-3-methyl-3,7-dihydro-1H-purine-2,6-dione

Smile: O=C(N(C)C(N=C(N1CCC[C@@H](N)C1)N2CC#CC)=C2C3=O)N3CC4=NC5=CC=CC=C5C(CC6(C)C(C=CC=C7)=C7NC(CN(C(N(C)C8=C9N(CC#CC)C(N%10CCC[C@@H](N)C%10)=N8)=O)C9=O)=N6)=N4