8-[(3R)-3-Amino-1-piperidinyl]-7-[(2E/Z)-3-bromo-2-buten-1-yl]-3,7-dihydro-3-methyl-1-[(4-methyl-2-quinazolinyl)methyl]-1H-purine-2,6-dione; Linagliptin Impurity S;N-Des-(2-butyn-1-yl)-N-(3-bromo-2-buten-1-yl) Linagliptin (E/Z Mixture)
8-[(3R)-3-Amino-1-piperidinyl]-7-[(2E/Z)-3-bromo-2-buten-1-yl]-3,7-dihydro-3-methyl-1-[(4-methyl-2-quinazolinyl)methyl]-1H-purine-2,6-dione; Linagliptin Impurity S;N-Des-(2-butyn-1-yl)-N-(3-bromo-2-buten-1-yl) Linagliptin (E/Z Mixture)