Linagliptin Impurity 11 Catalogue L562361 CAS 853029-57-9 M.W 453.29 M.F C20H17BrN6O2 Specifications FAQs 8-Bromo-7-(but-2-ynyl)-3-methyl-1-((4-methylquinazolin-2-yl)methyl)-1H-purine-2,6(3H,7H)-dione