Editing Pseudoephedrine (section)

===Nomenclatures===
The [[Levorotation and dextrorotation|dextrorotary]] (+)- or d- [[enantiomer]] is (1''S'',2''S'')-pseudoephedrine, whereas the levorotating (−)- or l- form is (1''R'',2''R'')-pseudoephedrine.

In the outdated [[Absolute configuration#By relative configuration: D- and L-|{{sc|d/l}} system]] (+)-pseudoephedrine is also referred to as {{sc|l-}}pseudoephedrine and (−)-pseudoephedrine as {{sc|d-}}pseudoephedrine (in the [[Fischer projection]] then the phenyl ring is drawn at bottom).<ref>{{cite journal | vauthors = Patil PN, Tye A, Lapidus JB | title = A Pharmacological Study of the Ephedrine Isomers | journal = The Journal of Pharmacology and Experimental Therapeutics | volume = 148 | issue = 2 | pages = 158–168 | date = May 1965 | doi = 10.1016/S0022-3565(25)27031-8 | pmid = 14301006 | url = http://jpet.aspetjournals.org/content/148/2/158.abstract | access-date = 24 December 2009 | archive-date = 7 January 2020 | archive-url = https://web.archive.org/web/20200107152211/http://jpet.aspetjournals.org/content/148/2/158.abstract | url-status = live }}</ref><ref>{{cite book| veditors = Reynolds JE | title=Martindale: The complete drug reference | edition=29th | year=1989 | publisher=Pharmaceutical Press | location=London | isbn= 0-85369-210-6 | author= Martindale| title-link=Martindale: The complete drug reference }}</ref>

Often the {{sc|d/l}} system (with [[small caps]]) and the [[Absolute configuration#By optical rotation: (+)- and (−)- or d- and l-|d/l system]] (with [[lower-case]]) are confused. The result is that the dextrorotary d-pseudoephedrine is wrongly named {{sc|d-}}pseudoephedrine and the levorotary l-ephedrine (the diastereomer) wrongly {{sc|l-}}ephedrine.

The IUPAC names of the two enantiomers are (1''S'',2''S'')- respectively (1''R'',2''R'')-2-methylamino-1-phenylpropan-1-ol. Synonyms for both are ''psi''-ephedrine and ''threo''-ephedrine.

Pseudoephedrine is the {{Abbrlink|INN|International Nonproprietary Name}} of the (+)-form, when used as pharmaceutical substance.<ref>[https://web.archive.org/web/20040627023842/http://whqlibdoc.who.int/inn/proposed_lists/prop_INN_list11.pdf ''Proposed International Non-Proprietary Names (Prop. I.N.N.): List 11''] WHO Chronicle, Vol. 15, No. 8, August 1961, pp. 314–20</ref>