Arbidol Impurity 6 Catalogue A124316 CAS 25900-97-4 M.W 398.52 M.F C22H26N2O3S Specifications FAQs ethyl 4-((dimethylamino)methyl)-5-hydroxy-1-methyl-2-((phenylthio)methyl)-1H-indole-3-carboxylate