N-Boc Linagliptin

: tert-Butyl(R)-(1-(7-(but-2-yn-1-yl)-3-methyl-1-((4-methylquinazolin-2-yl)methyl)-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-8-yl)piperidin-3-yl)carbamate;(R)-Tert-Butyl (1-(7-(but- 2-yn-1-yl)-3-methyl-1-((4- methylquinazolin-2- yl)methyl)-2,6-dioxo- 2,3,6,7-tetrahydro-1Hpurin- 8-yl)piperidin-3- yl)carbamate;N-[(3R)-1-[7-(2-Butyn-1-yl)-2,3,6,7-tetrahydro-3-methyl-1-[(4-methyl-2-quinazolinyl)methyl]-2,6-dioxo-1H-purin-8-yl]-3-piperidinyl]-carbamic Acid 1,1-Dimethylethyl Ester