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。
Synthesis of benzo[4,5]imidazo[1,2-<i>a</i>]pyrimidines and 2,3-dihydroquinazolin-4(1<i>H</i>)-ones under metal-free and solvent-free conditions for minimizing waste generation
efficient and recyclable catalyst for the synthesis of benzo[4,5]imidazo[1,2-a]pyrimidines and 2,3-dihydroquinazolin-4(1H)-ones. The reactions proceeded smoothly with a broad scope of substrates providing the expected products in good to excellent yields under an atom-economical pathway. The low-cost recyclable catalyst, metal- and solvent-freeconditions, and the ease of product isolation are the
发现 Brønsted 酸性离子液体是合成苯并[4,5]咪唑并[1,2 - a ]嘧啶和 2,3-二氢喹唑啉-4(1 H )-酮的有效且可回收的催化剂。该反应在广泛的底物范围内顺利进行,在原子经济途径下以良好至优异的产率提供了预期的产物。低成本的可回收催化剂、无金属和无溶剂条件以及易于产品分离是解决合成药物中痕量金属污染问题的突出优势。
Organocatalytic domino Knöevenagel–Michael reaction in water for the regioselective synthesis of benzo[4,5]imidazo[1,2-a]pyrimidines and pyrido[2,3-d]pyrimidin-2-amines
An organocatalyzed simple and general route towards the regioselectivesynthesis of benzo[4,5]imidazo[1,2-a]pyrimidines and pyrido[2,3-d]pyrimidin-2-amines is developed via L-proline catalyzed domino reaction of 2-aminobenzimidazole or 2,6-diaminopyrimidin-4-one with aldehydes and β-ketoesters in water. High yields within a shorter reaction time, simple purification, and environmentally benign mild
通过L-脯氨酸催化的邻氨基苯甲酸酯反应,建立了有机催化的通用途径进行区域选择性合成苯并[4,5]咪唑并[1,2- a ]嘧啶和吡啶并[2,3- d ]嘧啶2-胺的区域选择性合成。 2-氨基苯并咪唑或2,6-二氨基嘧啶-4-酮与醛和β-酮酸酯的水溶液。在较短的反应时间内实现高收率,简单的纯化以及对环境无害的温和反应条件是使该协议显着适用的关键特征。