作者:T. Blum、J. Ermert、H. H. Coenen
DOI:10.1002/jlcr.488
日期:2001.7
A convenient radiosynthesis of asymmetric [75Se]selenoethers was developed using 1,3-disubstituted [75Se]selenoureas as intermediates. These were prepared from appropriate carbodiimides and hydrogen [75Se]selenide, which could only be generated from carrier-added (c.a.) [75Se]selenite in aqueous solution using phosphinic acid as reducing agent. Optimization of this initial labelling step with dicyclohexylcarbodiimide and polymeric N-cyclohexylcarbodiimide-N′-methyl polystyrene resulted in radiochemical yields (RCY) of 73 and 55% (bound on the polymer), respectively, within 45 min. Treatment of [75Se]selenoureas with alkylbromides led to corresponding [75Se]selenouronium salts in nearly quantitative yields. Hydrolysis under basic conditions provided the [75Se]selenolates and a second alkylation yielded asymmetric [75Se]selenoethers. Thus, within 90 min benzylmethyl[75Se]selenide, benzylbutyl[75Se]selenide, benzylisopropyl[75Se]selenide and 1-phenyl-l-(methyl[75Se]seleno)ethane were synthesized with respective RCY of about 59, 55, 10 and 60%. Furthermore, the 75Se-labelled alkylating agent 3-(methyl[75Se]seleno)-1-propanyl p-toluenesulfonate and [75Se]selenomethionine were obtained with radiochemical yields of 51 and 41%, respectively. Copyright © 2001 John Wiley & Sons, Ltd.
使用1,3-二取代的[75Se]硒脲作为中间体开发了一种方便的不对称[75Se]硒醚放射合成方法。这些是由适当的碳二亚胺和[75Se]硒化氢制备而成,其只能使用次膦酸作为还原剂在水溶液中由添加载体的(c.a.)[75Se]亚硒酸盐产生。使用二环己基碳二亚胺和聚合 N-环己基碳二亚胺-N'-甲基聚苯乙烯优化初始标记步骤,45 分钟内放射化学产率 (RCY) 分别为 73% 和 55%(结合在聚合物上)。用烷基溴处理[75Se]硒脲以接近定量的产率产生相应的[75Se]硒脲盐。在碱性条件下水解提供[75Se]硒化物,第二次烷基化产生不对称[75Se]硒醚。因此,在90分钟内合成了苄基甲基[75Se]硒化物、苄基丁基[75Se]硒化物、苄基异丙基[75Se]硒化物和1-苯基-1-(甲基[75Se]硒基)乙烷,其RCY分别约为59、55、10和60%。此外,75Se标记的烷化剂3-(甲基[75Se]硒基)-1-丙酰对甲苯磺酸盐和[75Se]硒代蛋氨酸的放射化学收率分别为51%和41%。版权所有 © 2001 约翰·威利父子有限公司