在此,提供了一种区域选择性,省时和单反应路线,用于通过微波辅助方法以良好至优异的产率合成不同取代的3-卤代和3-硝基吡唑并[1,5- a ]嘧啶。该反应的特征在于β-烯酮与NH-5-氨基吡唑的顺序环缩合反应,然后用容易获得的亲电试剂进行区域选择性亲电取代。该方法的特点是反应时间短,产率高,操作简便,底物范围广和适用范围广。此外,这些3-官能化的杂环已成功地用于合成3-炔基和3-氨基吡唑并[1,5- a ]嘧啶,产率高达92%。
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。
Synthesis of Substituted Azaindenes: Synthesis of New Pyrazolo[1,5-<i>a</i>]pyrimidine Derivatives
作者:Mohamed Hilmy Elnagdi、Ayman Wahba Erian
DOI:10.1246/bcsj.63.1854
日期:1990.6
Severalnew pyrazolo[1,5-a]pyrimidines were synthesized via the reaction of 4,5-disubstituted 3-aminopyrazoles 1a–d with 3-dimethylaminopropiophenone, cinnamaldehyde, benzylideneacetophenone and tetracyanoethylene.
Rhodium(III)-Catalyzed Regioselective C(sp<sup>2</sup>)–H Functionalization of 7-Arylpyrazolo[1,5-<i>a</i>]pyrimidines with Dioxazolones as Amidating Agents
作者:Thirupathi Gogula、Jin-Quan Zhang、Hong-Bin Zou
DOI:10.1021/acs.orglett.9b02059
日期:2019.8.2
Rh(III)-catalyzed C–H functionalization of 7-arylpyrazolo[1,5-a]pyrimidines was developed wherein the pyrazolo[1,5-a]pyrimidine moiety is reported for the first time to direct the C–H bond activation. Various 7-arylpyrazolo[1,5-a]pyrimidines underwent smooth C–H amidation with alkyl-, aryl-, and heteroaryl-substituted dioxazolones to afford the products in moderate to good yields. Mechanistic studies
开发了Rh(III)催化的7-芳基吡唑并[1,5 - a ]嘧啶的CHH功能化,其中首次报道了吡唑并[1,5- a ]嘧啶部分指导CH键的活化。各种7-芳基吡唑并[1,5- a ]嘧啶经烷基,芳基和杂芳基取代的二恶唑酮进行平滑的CHH酰胺化反应,以中等至良好的收率得到产物。机理研究表明,涉及N1的六元Rhodacycle中间体可能在区域选择性催化循环中起关键作用。
Synthesis of Structurally Related Purines: Benzimidazo[1,2-a]pyridines, Benzimidazo-[1,2-c]pyrimidines, and Pyrazolo-[1,5-a]pyrimidines
作者:Galal H. Elgemeie、Nadia H. Metwally
DOI:10.1007/s007060050025
日期:——
alkanones with 2-cyanomethylbenzimidazole afforded benzimidazo[1,2- a ]pyridines. Analogues reactions with 2-aminobenzimidazole and 5-aminopyrazoles afforded benzimidazo[1,2- c ]pyrimidines and pyrazolo[1,5- a ]pyrimidines.