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