Vinylation of α-Aminoazoles with Triethylamine: A General Strategy to Construct Azolo[1,5-<i>a</i>]pyrimidines with a Nonsubstituted Ethylidene Fragment
作者:Qinghe Gao、Zhenhua Sun、Qinfei Xia、Ruonan Li、Wenlong Wang、Siwei Ma、Yixin Chai、Manman Wu、Wei Hu、Péter Ábrányi-Balogh、György M. Keserű、Xinya Han
DOI:10.1021/acs.orglett.1c00571
日期:2021.4.2
A new general synthesis of pharmaceutically important azolo[1,5-a]pyrimidines starting from widely available 3(5)-aminoazoles, aldehydes, and triethylamine is developed. The key is to enable the vinylation reaction that allows the in situ generation of elusive acyclic enamines and the subsequent annulation reaction to occur. This direct and practical strategy is capable of constructing a range of 5
从广泛可用的3(5)-氨基唑,醛和三乙胺开始,开发了一种重要的药学上重要的偶氮[1,5- a ]嘧啶的新的一般合成方法。关键是要实现乙烯基化反应,该反应可以原位产生难以捉摸的无环烯胺,并随后发生环化反应。这种直接而实用的策略能够构建一系列5,6-未取代的吡唑并[1,5- a ]嘧啶和[1,2,4]三唑并[1,5- a ]嘧啶。更重要的是,该方案为制备临床使用的扎来普隆提供了一种简明的合成途径。
A convenient, rapid, and highly selective method for synthesis of new pyrazolo[1,5-<i>a</i>]pyrimidines via the reaction of enaminones and 5-amino-1<i>H</i>-pyrazoles under microwave irradiation
Twelve new 7-aryl-3-cyanopyrazolo[1,5-a]pyrimidines (3a-f) and ethyl 7-arylpyrazolo[1,5-a]pyrimidine-3-carboxylates (3g-l) have been conveniently synthesized by the reaction of enaminones with 5-amino-1H-pyrazoles in good yields under microwaveirradiation. With one substituded enaminone, only one regioiso-mer was obtained. The structures of new compounds were fully confirmed by elemental analysis
十二种新的7-芳基-3-氰基吡唑并[1,5- a ]嘧啶(3a-f)和7-芳基吡唑并[1,5 - a ]嘧啶-3-羧酸乙酯(3g-1)通过微波辐射下烯胺酮与5-氨基-1 H-吡唑的高产率反应 用一种降级的烯胺酮,仅获得一种区域异构体。通过元素分析,ir,1 H nmr和X射线衍射(XRD)分析充分确认了新化合物的结构。提出了用于合成标题化合物的合理的反应机理。还报道了某些化合物的抗真菌活性。