Nalmefene Impurity C Catalogue N211333 CAS 16676-29-2 M.W 377.87 M.F C20H24ClNO4 Specifications FAQs (4R,4aS,7aR,12bS)-3-(cyclopropylmethyl)-4a,9-dihydroxy-2,3,4,4a,5,6-hexahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-7(7aH)-one hydrochloride