作者:Scott B. Tran、Ihoezo V. Ekhato、J. Kent Rinehart
DOI:10.1002/jlcr.1664
日期:2009.9.15
Entecavir, labeled as 1H-[13C4]purin-6(9H)-one, was prepared from commercially available [13C]guanidine HCl, 1 and diethyl [1,2,3-13C3]malonate, 2. The reagents were condensed together to give 2-amino-4,6-dichloro[2,4,5,6-13C4]pyrimidine 3, which in turn was coupled to an optically active amino cyclopentanol derivative, 9. A further sequence of eight reaction steps completed the constructions of the purine ring system and the exocyclic olefin attachment on the cyclic pentyl portion, 18. The removal of the methoxide and benzyl protecting groups gave [13C4]entecavir, 20 in an overall yield of 6.8%. The chemical purity of the title compound was determined by HPLC to be 99.23%. The percent isotopic [13C4] abundance was found by mass spectral analysis to be 96.7%. No detectable level of the unlabeled entecavir was found by LC-MS analysis. Copyright © 2009 John Wiley & Sons, Ltd.
恩替卡韦以市售的[13C]盐酸胍1和[1,2,3-13C3]丙二酸二乙酯2为原料制备出标记为1H-[13C4]嘌呤-6(9H)-酮的恩替卡韦。将这些试剂缩合在一起可得到2-氨基-4,6-二氯[2,4,5,6-13C4]嘧啶3,再将其与具有光学活性的氨基环戊醇衍生物9偶联。接下来的八个反应步骤完成了嘌呤环系统的构建和环戊基部分的外环烯烃连接,即 18。去除甲氧基和苄基保护基团后,得到[13C4]恩替卡韦 20,总产率为 6.8%。经 HPLC 测定,标题化合物的化学纯度为 99.23%。质谱分析发现,[13C4] 同位素丰度为 96.7%。通过 LC-MS 分析,没有发现未标记的恩替卡韦。Copyright © 2009 John Wiley & Sons, Ltd. All Rights Reserved.