The synthesis of isotopically labeled (+)-2-aminobicyclo[3.1.0]hexane-2,6-carboxylic acid and its 2-oxa- and 2-thia-analogs
作者:William J. Wheeler、Douglas D. O'Bannon、Joseph H. Kennedy、James A. Monn、Roger W. Tharp-Taylor、Matthew J. Valli、Fengjiun Kuo
DOI:10.1002/jlcr.956
日期:2005.7
As part of a program aimed at the design of conformationally constrained analogs of glutamic acid, (+)-2-aminobicyclo[3.1.0]hexane-2,6-carboxylic acid (1), identified as a highly potent, selective, group II metabotropic glutamate receptor agonist has been synthesized and studied clinically. Heterocyclic analogs of 1 were subsequently synthesized in which the C-2 methylene has been replaced by an oxygen atom (2) or a sulfur atom (3). C-14 labeled isotopomers of 1, 2 and 3 have been synthesized to facilitate pre-clinical ADME studies. A tritium labeled isotopomer of 1 was also synthesized for use in in vitro experiments. A stable labeled isotopomer of rac-1 was prepared for use as an internal standard for bioanalytical assays. The key step in each of these syntheses was the reaction of chiral ketone 4, 5 or 6 with K14CN/(NH4)2CO3 using the Bucherer–Berg protocol. In the preparation of the stable labeled isotopomer, rac-4-[13C2] was prepared in two steps from ethyl bromoacetate-[UL-13C2]; subsequent reaction of rac-4-[13C2] with K13CN/15NH4Cl/Na2CO3, followed by hydrolysis of the hydantoin yielded rac-1-[13C3,15N]. Copyright © 2005 John Wiley & Sons, Ltd.
作为旨在设计构象限制型谷氨酸类似物的项目的一部分,合成并临床研究了(+)-2-氨基双环[3.1.0]己烷-2,6-羧酸(1),该化合物被确定为一种高度有效、选择性的二类代谢型谷氨酸受体激动剂。随后合成了1的杂环类似物,其中C-2亚甲基被氧原子(2)或硫原子(3)取代。合成了1、2和3的C-14标记同位素,以方便进行临床前的ADME研究。还合成了1的氚标记同位素,用于体外实验。为生物分析检测准备了稳定的标记同位素rac-1作为内标。这些合成中的关键步骤是手性酮4、5或6与K14CN/(NH4)2CO3的反应,采用Bucherer–Berg协议。在稳定标记同位素的制备中,rac-4-[13C2]是通过从乙基溴乙酸酯-[UL-13C2]的两步反应制得的;随后将rac-4-[13C2]与K13CN/15NH4Cl/Na2CO3反应,接着进行酰脲的水解,最终得到rac-1-[13C3,15N]。版权 © 2005 John Wiley & Sons, Ltd.