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).

中文翻译：

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C-核糖基咪唑并[2,1- f ] [1,2,4]三嗪的合成作为腺苷和AMP脱氨酶的抑制剂

新的咪唑并[2,1 - f ] [1,2,4]三嗪27的3-β- D-核呋喃糖苷6与核苷脱氨基甲霉素1（是腺苷脱氨酶（ADA）的良好抑制剂）同分异构和等电子。它的5'-单磷酸2是腺苷5'-单磷酸脱氨酶（AMPDA）的良好抑制剂。6的6-甲基硫烷基衍生物7是通过将单环1,2,4-三嗪9与溴醛10缩合而合成的，然后将其环化以得到被保护的C-核苷21; 通过用肼置换和氧化除去21的8-甲基硫烷基。1,2,4-三嗪9与氯乙醛或其二甲基乙缩醛类似地环化，得到6,8-双（甲基硫烷基）咪唑并[2,1- f] [1,2,4]三嗪17，它通过两种途径转化为母体杂环27，并转化为新环系统的单取代和双取代衍生物（19、20、24、25、28-30） 。核苷7是哺乳动物ADA（IC ₅₀ 40 µM）的抑制剂。