Spectrum Chemical manufactures and distributes fine chemicals with quality you can count on including those with CAS number 51-41-2, Whether you call it L-Norepinephrine, (R)-4-(2-Amino-1-hydroxyethyl)-1 -2-benzenediol , Levarterenol or L-Arterenol you can be assured the L-Norepinephrine products offered by Spectrum, meet or exceed the grade requirements or specifications for each individual product.