Azithromycin EP Impurity J Catalogue A535210 CAS 117693-41-1 M.W 590.80 M.F C30H58N2O9 Specifications FAQs (2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-(((2S,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)-2-ethyl-3,4,10,13-tetrahydroxy-3,5,6,8,10,12,14-heptamethyl-1-oxa-6-azacyclopentadecan-15-one