Preparation of [11C]diethyl oxalate and [11C]oxalic acid and demonstration of their use in the synthesis of [11C]-2,3-dihydroxyquinoxaline
作者:Jan-Olov Thorell、Sharon Stone-Elander、Nils Elander
DOI:10.1002/jlcr.2580331102
日期:1993.11
A method for the production of two new carbon-11 labelled difunctional radiolabelling precursors, [11C]diethyl oxalate, 2, and [11C]oxalic acid, 3, is described. Methyl chloroformate was reacted with no-carrier-added [11C]cyanide to generate the intermediate nitrile, methyl [11C]cyanoformate. Alcoholysis with HCl in ethanol generated 2, with could subsequently be converted to 3, with aqueous acid. The total time of preparation from end-of-trapping of [11C]cyanide was 6-7 min using combined microwave and thermal treatment or, by exclusively thermal treatment, 15 and 20 min for 2 and 3, respectively. The radiochemical conversion of [11C]cyanide to 2 and 3 was ∼80% and ∼70%, respectively. Both 2 and 3 were used in a model reaction with 1,2-phenylenediamine to synthesize the heterocyclic compound, 2,3-dihydroxyquinoxaline, a basic structural unit in antagonists for the excitatory amino acid receptor system.
本文介绍了一种生产[11C]草酸二乙酯 2 和[11C]草酸 3 这两种新的碳-11 标记双官能团放射性标记前体的方法。氯甲酸甲酯与无载体添加的[11C]氰化物反应生成中间腈--[11C]氰基甲酸甲酯。在乙醇中用盐酸进行烷氧基化反应生成 2,随后可在水酸的作用下转化为 3。采用微波和热处理相结合的方法制备[11C]氰化物,从俘获结束到制备完成的总时间为 6-7 分钟;而只采用热处理的方法制备 2 和 3,总时间分别为 15 和 20 分钟。[11C]氰化物到 2 和 3 的放射化学转化率分别为 80% 和 70%。在与 1,2-苯二胺的模型反应中,2 和 3 被用于合成杂环化合物 2,3-二羟基喹喔啉,这是兴奋性氨基酸受体系统拮抗剂的基本结构单元。