Desloratadine Impurity 9 Catalogue D225642 CAS 117811-11-7 M.W 324.81 M.F C19H17ClN2O Specifications FAQs 8-chloro-11-(piperidin-4-ylidene)-6,11-dihydro-5H-benzo[5,6]cyclohepta[1,2-b]pyridin-5-one