1,4,7,10-四氮杂环十二院的合成研究

多氮杂环化合物及其衍生物近年来愈来愈显示出其重要而广泛的用途，譬如：可作为人体内结石的清除药物［‘·’j，作为MnSOD的模拟物可抑制心肌缺血性再灌注引起的损伤［’j，且具有抗爱滋病活性等；尤其是在制造磁共振成像（MRI）、X射线CT、超声成像等医学影像技术的造影剂以及恶性肿瘤的放射性治疗药物方面［‘－’‘，多氨杂环烷烃特别是1，4，7，10一四氮染环十二烷（Cyclen，环楞胺）及其衍生物显示出极其重要的应用价值．多氨杂环烷烃及其衍生物可因具体情况有不同的合成方法，环楞胺最初由乙二胶二乙酸氯与乙二胺在高度稀释条…

A New Approach to the Synthesis of 1, 4, 7, 10-Tetraazacyclododecane

A new and simplified method for synthesis 1, 4, 7, 10-tetraazacyclododecane (cy-clen) has been proposed by two steps in this paper. The first step deals with cyclic condensa-tion of triethylenetetramine and diethyl oxalate in methanolic solution, giving the twelve-numbered cyclic oxamide, i. e., 1, 4, 7,10-tetraazacyclododecane-2, 3-dione.The pure prod-uct was obtained as a crystalline precipitate in 39% yield on addition of ethanol to the con-centrated solution of the reaction mixture. Subsequently, in the second step, the cyclic ox-amide was reduced in THF with diborane produced in situ fr6m potassium borohydride andboron trifluoride etherate and extracted by CH2Cl2 from the basic aqueous solution of the sol-vent free residue, giving cyclen in 56% yield after removing the solvent.