Synthesis of C-ribosyl imidazo[2,1-f ][1,2,4]triazines as inhibitors of adenosine and AMP deaminases
作者:Philip J. Dudfield、Van-Duc Le、Stephen D. Lindell、Charles W. Rees
DOI:10.1039/a904065j
日期:——
The 3-β-D-ribofuranoside 6 of the new imidazo[2,1-f][1,2,4]triazine 27 is isomeric and isoelectronic with the nucleoside deaminoformycin 1 which is a good inhibitor of adenosine deaminase (ADA) while its 5′-monophosphate 2 is a good inhibitor of adenosine 5′-monophosphate deaminase (AMPDA). The 6-methylsulfanyl derivative 7 of 6 is synthesized by condensation of the monocyclic 1,2,4-triazine 9 with bromo aldehyde 10, which is accompanied by cyclization to give the protected C-nucleoside 21; the 8-methylsulfanyl group of 21 is removed by replacement by hydrazine and oxidation. The 1,2,4-triazine 9 cyclizes similarly with chloroacetaldehyde or its dimethyl acetal to give 6,8-bis(methylsulfanyl)imidazo[2,1-f][1,2,4]triazine 17, which is converted into the parent heterocycle 27 by two routes, and into mono- and di-substituted derivatives (19, 20, 24, 25, 28–30) of the new ring system. Riboside 7 is an inhibitor of mammalian ADA (IC50 40 µM).
新咪唑并[2,1-f][1,2,4]三嗪 27 的 3-β-D-ribofuranoside 6 与核苷脱氨基福尔马林 1 是同分异构体和等电子体,后者是腺苷脱氨酶 (ADA) 的良好抑制剂,而其 5′-monophosphate 2 则是腺苷 5′-monophosphate deaminase (AMPDA) 的良好抑制剂。6 的 6-甲硫基衍生物 7 是通过单环 1,2,4-三嗪 9 与溴醛 10 缩合合成的,缩合过程伴随着环化反应,从而得到受保护的 C 核苷 21;21 的 8-甲硫基通过肼置换和氧化作用去除。1,2,4-三嗪 9 与氯乙醛或其二甲基缩醛发生类似的环化反应,得到 6,8-双(甲硫基)咪唑并[2,1-f][1,2,4]三嗪 17,通过两种途径转化为母杂环 27,以及新环系统的单取代和二取代衍生物(19、20、24、25、28-30)。核苷 7 是哺乳动物 ADA 的抑制剂(IC50 40 µM)。