1',3-联吡咯-2-羧酸乙酯的合成

Synthesis of Ethyl 1H-[1',3-bipyrrole]-2-carboxylate

以异噁唑为原料,经碱性开环、亲核加成、成环脱羧、Clauson-Kaas四步反应合成了1',3-联吡咯-2-羧酸乙酯,其结构经1H-NMR确认。由于本方法中异噁唑碱性开环与加成两步反应实现一锅法,并对脱羧成环及Clauson-Kaas反应条件进行了优化,简化了工艺操作,降低了分离难度,提高了收率和产品纯度,适用于公斤级生产。

1H-[1′,3 -bipyrrole] -2 -carboxylate was synthesized from isodaxale by employing four steps of reaction with base -catalyzed ring opening , nucleophilic addition , decarboxylation -cyclization and Clauson -Kaas reaction.Structure of the products was characterized by 1^ H-NMR.Since base-catalyzed ring opening of isoxazole and the nucleophilic addition was achieved in a one -pot procedure , reaction conditions of decarboxylation -cyclization and Clauson-Kaas reaction were optimized , the synthetic and isolation process was simplified , and yield and purity were increased , which was suitable for large -scale production.