Linagliptin Impurity M Catalogue L562378 CAS 1791405-13-4 M.W 316.36 M.F C15H20N6O2 Specifications FAQs (R)-8-(3-aminopiperidin-1-yl)-7-(but-2-yn-1-yl)-3-methyl-1H-purine-2,6(3H,7H)-dione