3-硝基-2-取代噻吩的简便合成。

Facile synthesis of 3-nitro-2-substituted thiophenes.

机构信息

Centre for Synthesis and Chemical Biology, School of Chemistry, University of Dublin, Trinity College, Dublin 2, Ireland.

出版信息

J Org Chem. 2010 Apr 16;75(8):2534-8. doi: 10.1021/jo902656y.

DOI:10.1021/jo902656y

PMID:20302382

Abstract

A new approach to 3-nitro-2-substituted thiophenes has been developed. Exposure of commercially available 1,4-dithane-2,5-diol to nitroalkenes in the presence of 20% triethylamine results in a tandem Michael-intramolecular Henry reaction to form the corresponding tetrahydrothiophene. Subsequent microwave irradiation on acidic alumina in the presence of chloranil effects the solvent free dehydration and aromatization to form 3-nitro-2-substituted thiophenes cleanly and rapidly. A simple workup procedure removes the requirement for purification by chromatography in most cases.

摘要

已经开发出一种合成 3-硝基-2-取代噻吩的新方法。在 20%三乙胺存在下，将商业可得的 1,4-二硫烷-2,5-二醇暴露于硝基烯烃中，会发生串联迈克尔-分子内 Henry 反应，形成相应的四氢噻吩。随后在氯代蒽醌存在下，在酸性氧化铝上进行微波辐射，可在无溶剂条件下进行脱水和芳构化，以快速、干净地形成 3-硝基-2-取代噻吩。在大多数情况下，简单的后处理步骤可省去通过色谱进行纯化的要求。