title: Preparation of 2'-13C-L-histidine starting from 13C-thiocyanate: synthetic access to any site-directed stable isotope enriched L-histidine.
abstract: 1-Benzyl-2-(methylthio)-imidazole-5-ketone is obtained in a few simple steps starting from thiocyanate and glycine amide (glycin). Subsequent treatment with diethyl phosphorocyanidate and functional group manipulations gives 1-benzyl-5-chloromethyl-imidazolium chloride. This compound is converted under mild O'Donnell conditions into the corresponding L-histidine derivative. After deprotection L-histidine is obtained in good yield and 99% enantiomeric excess. 2'-13C-L-Histidine has been obtained via this new scheme with high (99%) 13C incorporation starting with commercially available 13C- thiocyanate. This synthetic scheme allows access to any isotopomer of L-histidine and many other biologically important imidazole derivatives.
authors.affiliation: Department of Chemistry, College of Applied and Industrial Science, University of Bahri, P.O. Box 11111, Khartoum 1660, Sudan. Stalab9@gmail.com.
authors.forename: Sarra
authors.initials: S
authors.lastname: Talab
authors.affiliation: Department of Chemistry, College of Applied and Industrial Science, University of Bahri, P.O. Box 11111, Khartoum 1660, Sudan. kamaltha99@rediffmail.com.
authors.forename: Kamal Khalifa
authors.initials: KK
authors.lastname: Taha
authors.affiliation: Department of Chemistry, College of Applied and Industrial Science, University of Bahri, P.O. Box 11111, Khartoum 1660, Sudan. lugtenbu@chem.leidenuniv.nl.
authors.forename: Johan
authors.initials: J
authors.lastname: Lugtenburg
mesh_terms: D002250:Carbon Radioisotopes / Q000737:chemistry; D003500:Cyclization; D006639:Histidine / Q000138:chemical synthesis*; D007093:Imidazoles / Q000138:chemical synthesis; D007553:Isotope Labeling; D013861:Thiocyanates / Q000737:chemistry*
chemical_list: D002250:Carbon Radioisotopes; D007093:Imidazoles; D013861:Thiocyanates; D006639:Histidine; C031760:thiocyanate