Formoterol EP Impurity B (Fumarate)

Chemical Name: N-[2-hydroxy-5-[(1RS)-1-hydroxy-2-[[2-(4-methoxyphenyl)ethyl]amino]ethyl]phenyl]formamide fumaric acid (as per EP); N-(2-Hydroxy-5-{1-hydroxy-2-[(4-methoxyphenethyl)amino]ethyl}phenyl)formamide Fumaric acid (as per USP)

Synonym: Desmethyl formoterol (USP)

Smile: COC1=CC=C(CCNCC(C2=CC=C(O)C(NC=O)=C2)O)C=C1.O=C(O)/C=C/C(O)=O