An efficient protocol for the synthesis of 14C-labeled 3-pyridineacetate (1) and its N-oxide ([14C]2) is described. Oxidation of this pyridine ([14C]1) to its N-oxide ([14C]2) proceeded in high yield using H2O2 with MeReO3 as a catalyst. The reaction employs readily available diethyl [2-14C]malonate. This method has proven to be general in preparation of other pyridineacetate derivatives and their N-oxides which have been typically difficult to prepare by other means. Our development of the Cu(I)Br-coupling methodology as well as application to the synthesis of a 14C-labeled phosphodiesterase-IV (PDE-IV) inhibitor, [14C]3, are also reported. Copyright © 2007 John Wiley & Sons, Ltd.
描述了一种高效的合成14C标记的
3-吡啶乙酸酯(1)及其N-氧化物([14C]2)的方法。使用
H2O2和MeReO3作为催化剂,可以高产率地将该
吡啶([14C]1)氧化为其N-氧化物([14C]2)。该反应采用易得的
二乙基[2-14C]
丙二酸酯。该方法在制备其他
吡啶乙酸酯衍
生物及其N-氧化物方面已证明具有普遍适用性,这些化合物通常通过其他方法难以制备。我们还报告了Cu(I)Br偶联方法的开发以及其在合成14C标记的
磷酸二酯酶-IV(PDE-IV)
抑制剂[14C]3中的应用。版权 © 2007 John Wiley & Sons, Ltd.