LCZ696 Impurity 16 Catalogue L524686 CAS 2216746-87-9 M.W 365.42 M.F C22H23NO4 Specifications FAQs (3S,5R)-4-[5-([1,1'-Biphenyl]-4-ylmethyl)-3-methyl-2-oxopyrrolidin-1-yl]-4-oxobutanoic acid