for the following products
(1R,1'R)-2,2'-(3,11-dioxo-4,10-dioxatridecamethylene)-bis-(1,2,3,4-tetrahydro-6,7-dimethoxy-1-veratrylisoquindline)-dioxalate | Atracurium besylate ep impurity b (oxalate salt) | cis-Atracurium oxalate and (1R,1'R)-Atracurium dioxalate
