title: No-carrier-added synthesis of aliphatic and aromatic radioselenoethers via selenocyanates.
abstract: Various aliphatic and aromatic [(75)Se]selenoethers were prepared at the no-carrier-added (n.c.a.) level using a new radiosynthetic pathway, based on the formation of alkyl[(75)Se]selenocyanates as intermediates. Using one-pot model reactions of elemental (75)Se, sodium cyanide and various alkylbromides in ethanol, the preparation of alkyl[(75)Se]selenocyanates was examined and optimized. Purification of these (75)Se-labeled intermediates and subsequent conversion with alkyl and aryl lithium or Grignard compounds in anhydrous diethyl ether yielded radioselenoethers with radiochemical yields of up to 55% (related to (75)Se(0)) within an overall reaction time of 20 min. This is the first method described to obtain n.c.a. arylselenoethers.
authors.affiliation: Institut für Nuklearchemie, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.
authors.forename: Till
authors.initials: T
authors.lastname: Blum
authors.forename: Johannes
authors.initials: J
authors.lastname: Ermert
authors.forename: Heinz H
authors.initials: HH
authors.lastname: Coenen
mesh_terms: D003485:Cyanates / Q000138:chemical synthesis* / Q000737:chemistry; D004987:Ethers / Q000138:chemical synthesis / Q000737:chemistry; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000737:chemistry; D018036:Selenium Compounds / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D003485:Cyanates; D004987:Ethers; D019275:Radiopharmaceuticals; D018036:Selenium Compounds; C053721:selenocyanic acid