Condensation of 5(3)-amino-3(5)-arylpyrazoles with 4-hydroxy-6-methylpyran-2-one leads to 5,7-dimethyl-2-arylpyrazolo[1,5-a]pyrimidines, 5-alkoxycarbonylmethyl-7-methyl-2-arylpyrazolo[1,5-a]pyrimidines and their isomeric 7-alkoxycarbonylmethyl-5-methyl-2-arylpyrazolo[1,5-a]pyrimidines. These compounds result from competitive reactions and from different cyclization pathways. Structure and mechanism of formation of these new products are reported. (C) 2011 Elsevier Ltd. All rights reserved.
Aggarwal, Ranjana; Rani, Chinu; Kumar, Rajiv, Indian Journal of Heterocyclic Chemistry, 2015, vol. 24, # 4, p. 419 - 428
作者:Aggarwal, Ranjana、Rani, Chinu、Kumar, Rajiv
DOI:——
日期:——
A one-pot process for the microwave-assisted synthesis of 7-substituted pyrazolo[1,5-a]pyrimidine
An efficient synthesis of 7-substituted pyrazolo[1,5-a]pyrimidines using a one-pot, two-step process via Pd-catalyzed direct CH-arylation followed by a saponification–decarboxylation reaction is reported. Compared to the classical method (Negishi coupling), this new procedure has the advantages of convenient manipulation, short reaction times, excellent yields and the use of commercially available
据报道,使用一锅,两步法通过Pd催化的直接CH-芳基化反应,然后进行皂化-脱羧化反应,可以有效合成7-取代的吡唑并[1,5- a ]嘧啶。与传统方法(Negishi偶联)相比,该新方法具有操作方便,反应时间短,产率高以及使用市售且相对无毒的化合物的优点。