Microwave-assisted efficient synthesis of benzo[4,5]imidazo[1,2-a]-pyrimidine derivatives in water under catalyst-free conditions
作者:Shujiang Tu、Qingqing Shao、Dianxiang Zhou、Longji Cao、Feng Shi、Chunmei Li
DOI:10.1002/jhet.5570440625
日期:2007.11
2-a]pyrimidine derivatives were synthesized via the three-component reaction of aldehyde, β-dicarbonylcompound and 2-aminobenzimidazole in water under microwave irradiation and without catalyst conditions. The new protocol has the advantages of higher yield, lower cost, reduced environment impact, wider scope and convenient procedure.
苯并[4,5]咪唑并[1,2- a ]嘧啶衍生物是通过醛,β-二羰基化合物和2-氨基苯并咪唑在微波辐射下且无催化剂条件下在水中进行三组分反应而合成的。新协议具有产量高,成本低,对环境影响小,适用范围广,操作方便等优点。
One-Pot Synthesis of Pyrimido[1,2-<i>a</i>]benzimidazoles under Solvent-Free Conditions
A series of pyrimido[1,2‐a]benzimidazoles were obtained from aldehydes, 2‐aminobenzimidazole and ethyl acetoacetate in good‐to‐excellent yields by a simple, mild, and efficient procedure utilizing N,N,N′,N′‐tetrabromobenzene‐1,3‐disulfonamide (TBBDA) and poly(N‐bromo‐N‐ethylbenzene‐1,3‐disulfonamide) (PBBS) as catalysts.
通过使用N,N,N',N'-的简单,温和且有效的方法,从醛,2-氨基苯并咪唑和乙酰乙酸乙酯中获得了一系列嘧啶[1,2- a ]苯并咪唑,收率良好至优异。四溴苯-1,3-二磺酰胺(TBBDA)和聚(N-溴-N-乙基苯-1,3-二磺酰胺)(PBBS)作为催化剂。
Preparation and characterization of copper/polysulfonamide complex immobilized on geraphene oxide as a novel catalyst for the synthesis of pyrimido[1,2‐a]benzimidazoles
Copper–polysulfonamide complex immobilized on geraphene oxide as a novel heterogeneous catalyst (GO@PSA‐Cu) was synthesized and the structure and morphology of catalyst were characterized with various analytical techniques such as Fourier‐transform infrared spectroscopy, scanning electron microscopy, energy‐dispersive X‐ray, N2 isotherms, elemental mapping, inductively coupled plasma–MS, and thermogravimetric
Nano-Co-[4-chlorophenyl-salicylaldimine-pyranopyrimidine dione]Cl2 as a new Schiff base complex and catalyst for the one-pot synthesis of some 4H-pyrimido[2,1-b]benzazoles
was prepared and fully characterized as a new nano-Schiff base complex. Nano-[Co-4CSP]Cl2 was successfully used as an efficient catalyst for the synthesis of some4H-pyrimido[2,1-b]benzazoles such as 4H-pyrimido[2,1-b]benzothiazoles and 4H-pyrimido[2,1-b]benzimidazoles.