Expeditious Solid-Phase Synthesis of Pyrazoledicarboxylic Acid Derivatives by Functionalization of Resin-Bound Cyanoformate
作者:Carlo F. Morelli、Alberto Saladino、Giovanna Speranza、Paolo Manitto
DOI:10.1002/ejoc.200500381
日期:2005.11
Esterification of the Wang resin 5 with the monoamide of oxalic acid (oxamic acid, 7) followed by dehydration of the amide function furnishes the resin-bound cyanoformate 9, which can be elaborated by zinc-catalyzed reaction with β-keto esters. The obtained enamino keto diesters 10a–d react with hydrazines affording, after removal from the solid support, fully substituted pyrazoledicarboxylic acids
Wang 树脂 5 与草酸(草酸,7)的单酰胺酯化,然后酰胺官能团脱水,得到树脂结合的氰基甲酸酯 9,它可以通过锌催化与 β-酮酯反应制备。获得的烯氨基酮二酯 10a-d 与肼反应,从固体载体上去除后,得到完全取代的吡唑二羧酸 12a-n。描述了上述序列的优化和 1,5-二取代吡唑-3,4-二羧酸衍生物的小型测试库的固相合成。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)