chloro)succinimide, and sodium azide at 25–45 °C. These C-5 halogenation reactions proceed via a 5-halo-6-azido-5,6-dihydro intermediate (3), from which HN3 is eliminated, to yield the 5-halogeno uracil nucleoside. The 5-halo-6-azido-5,6-dihydro intermediate products (10a, 10b) could be isolated from the reaction of 3′,5′-di-O-acetyl-2′-deoxyuridine (9) with iodine monochloride or N-bromosuccinimide and
已开发出一种温和有效的方法来合成 5-卤代(
碘、
溴或
氯)尿
嘧啶核苷。5-Halo-2'-deoxyuridines 4a–c (84–95%), 5-halo-arabinouridines 7a–c (45–95%), and 5-haloarabinouridines 8a–c (65–95%) 合成良好
2'-脱氧尿苷 (2)、
尿苷 (5) 和阿拉伯
尿苷 (6) 分别与
一氯化碘或 N-
溴(或
氯)琥珀
酰亚胺和
叠氮化
钠在 25–45 °C 下反应生成。这些 C-5 卤化反应通过 5-卤代-6-
叠氮基-5,6-二氢中间体 (3) 进行,从中消除
HN3,生成 5-卤代尿
嘧啶核苷。5-halo-6-azido-5,6-dihydro 中间产物 (10a, 10b) 可以从 3',5'-di-O-acetyl-2'-deoxyuridine (9) 与
一氯化碘的反应中分离出来或 N-
溴代琥珀
酰亚胺和
叠氮化
钠在