Dihydroergotamine EP Impurity B

Chemical Name: (6aR,9R,10aR)-N-[(2R,5S,10aS,10bS)-5-Benzyl-2-ethyl-10b-hydroxy-3,6-dioxooctahydro-8H-oxazolo[3,2-a]pyrrolo[2,1-c]pyrazin-2-yl]-7-methyl-4,6,6a,7,8,9,10,10a-octahydroindolo[4,3-fg]quinoline-9-carboxamide (as per EP)

Synonym: 9,10-Dihydroergostine