Aziridines may be subjected to a cyclooligomerization reaction to produce polyazacycloalkane compounds useful for example in the preparation of chelating agents for use in diagnostic imaging contrast agents. N-benzyl-aziridine in particular is useful as it can be cyclotetramerized and debenzylated to yield cyclen, a key intermediate in chelating agent preparation. The invention provides a particularly attractive route to production of N-benzyl and other N-arylmethyl aziridines of formula (I) where each R.sub.1 is independently hydrogen or a group AR and Ar is an optionally substituted phenyl group. The process comprises reacting a purified N-arylmethylethanolaminesulphonate ester with a base. N-arylmethyl-ethanolamine sulphonate ester of the formula R'NHCH.sub.2 CH.sub.2 OSO.sub.3 H, wherein the N-arylmethyl group R' is an N-(bisarylmethyl) or N-(triarylmethyl) group, as intermediates. In a further aspect, the invention provides compounds of formula (II) ##STR1## where Ar and R.sub.1 are as hereinabove defined and at least two differing ArCHR.sub.21 moieties are present.
Aziridines 可以经历环寡聚化反应,产生聚合物,这些聚合物在制备用于诊断成像对比剂中的
螯合剂中非常有用。特别是 N-苄基-
环丙烷是有用的,因为它可以进行环四聚化和脱苄基化,产生
环己胺,这是
螯合剂制备中的关键中间体。该发明提供了一种特别有吸引力的生产 N-苄基和其他 N-芳基
甲基环丙烷的路线,其中每个 R.sub.1 独立地是氢或基团 AR,Ar 是一个可选择取代的苯基团。该过程包括将纯化的 N-芳基甲基
乙醇胺
磺酸酯与碱反应。N-芳基甲基
乙醇胺
磺酸酯的
化学式为 R'NHCH.sub.2 CH.sub.2 OSO.sub.3 H,其中 N-芳基甲基基团 R' 是 N-(双芳基甲基) 或 N-(三芳基甲基) 基团,作为中间体。此外,该发明提供了化合物的
化学式 (II) ##STR1## 其中 Ar 和 R.sub.1 如上所定义,至少存在两个不同的 ArCHR.sub.21 基团。