Synthesis of novel 5‐chlorinated 2‐aminothiophenes using 2,5‐dimethylpyrrole as an amine protecting group
作者:Zita Puterová、Tomáš Bobula、Daniel Végh
DOI:10.1002/jhet.5570450124
日期:2008.1
free positions of 2,5-dimethylpyrrole were substituted. To direct chlorination to the thiophene ring acetamido derivative was prepared first and then chlorinated. Transamination with hexane-2,5-dione created a 2,5-dimethyl pyrrole ring from the acetamido group. In the final step, after treatment with hydroxylamine dihydrochloride, the pyrrole ring is removed and a free amino group is regenerated.
描述了一种针对取代的2-氨基-5-氯噻吩的新合成方法。这种类型的化合物作为聚合物研究中使用的低聚物的重要组成部分很重要。容易获得的2-氨基噻吩在进行亲电取代之前,进行了Paal-Knorr反应以保护游离氨基。尽管预计氯化会在噻吩环上进行,但仅2,5-二甲基吡咯的自由位置被取代。为了直接氯化成噻吩环,首先要制备乙酰氨基衍生物,然后再进行氯化。用2,5-己二酸己烷酯转氨从乙酰胺基生成2,5-二甲基吡咯环。在最后的步骤中,用二羟胺盐酸盐处理后,除去吡咯环,并再生出游离氨基。