Regioselective and efficient halogenation of 4,5-unsubstituted alkyl 3-hydroxypyrrole/3-hydroxythiophene-2-yl-carboxylates
作者:Omar Castillo-Aguilera、Patrick Depreux、Ludovic Halby、Nathalie Azaroual、Paola B. Arimondo、Laurence Goossens
DOI:10.1016/j.tetlet.2017.05.025
日期:2017.6
in the field of pharmaceutical and material sciences. Here we studied the reactivity of 4,5-unsubstituted alkyl 3-hydroxypyrrol-2-yl-carboxylates and 4,5-unsubstituted alkyl 3-hydroxythiophen-2-yl-carboxylates in different halogenation conditions, due to their interest as building blocks in the synthesis of bioactive compounds and materials. We describe herein the regioselective monohalogenation of
取代的杂环,例如吡咯和噻吩,在药物和材料科学领域中很常见。在这里,我们研究了4,5-未取代的3-羟基吡咯-2-基-羧酸盐和4,5-未取代的烷基3-羟基噻吩-2-基-羧酸盐在不同卤化条件下的反应性,这是由于它们作为结构单元的兴趣。生物活性化合物和材料的合成。我们在本文中描述了在普通条件下用普通卤化剂对3-羟基吡咯和3-羟基噻吩进行区域选择性单卤代反应。研究了卤化的选择性。发现了用于单溴化和单氯化的最佳一步反应条件。最后,我们观察到用N溴化-溴琥珀酰亚胺(NBS)发生在杂环的C4位,而用SO 2 Cl 2氯化则生成C5卤代衍生物。