title: Synthesis of [75Se]trimethylselenonium iodide from [75Se]selenocystine.
abstract: The synthesis of [75Se]trimethylselenonium iodide from [75Se]selenocystine is described. The starting compound is reduced to [75Se]selenocysteine with borohydride and reacted with methyl iodide to form [75Se]Se-methyl-selenocysteine, then treated with methyl iodide in formic acid solution to form Se-dimethyl-selenocysteine selenonium iodide. Over a period of days, the selenonium intermediate undergoes spontaneous elimination to form alanine and dimethyl selenide, which reacts with methyl iodide to give the trimethylselenonium product in over 90% yield.
mesh_terms: D001894:Borohydrides; D055598:Chemical Phenomena; D002621:Chemistry; D003545:Cysteine / Q000031:analogs & derivatives / Q000138:chemical synthesis; D003553:Cystine / Q000031:analogs & derivatives*; D006847:Hydrocarbons, Iodinated; D008722:Methods; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000302:isolation & purification; D016566:Organoselenium Compounds; D011868:Radioisotopes; D012643:Selenium / Q000138:chemical synthesis* / Q000302:isolation & purification; D018036:Selenium Compounds; D017279:Selenocysteine / Q000031:analogs & derivatives
chemical_list: D001894:Borohydrides; D006847:Hydrocarbons, Iodinated; D009942:Organometallic Compounds; D016566:Organoselenium Compounds; D011868:Radioisotopes; D018036:Selenium Compounds; D017279:Selenocysteine; C009226:selenocystine; D003553:Cystine; C025364:sodium borohydride; C014055:methyl iodide; D012643:Selenium; D003545:Cysteine; C003717:trimethylselenonium; C002979:selenomethylselenocysteine