Cs2CO3催化下多组分一锅法合成螺吲哚-三唑并[1,5-a] 嘧啶及螺吲哚-苯并咪唑并[1,2-a]嘧啶类化合物

以3-氨基-1,2,4-三唑(或2-氨基苯并咪唑)、靛红和丙二腈为原料,经三组分一锅法合成了7种新型的螺吲哚-三唑并[1,5-a]嘧啶类化合物（1a~1g）和5种新型的螺吲哚 苯并咪唑并[1,2-a]嘧啶类化合物（2a, 2c, 2d, 2e, 2g）,其结构经¹H NMR, IR和HR-MS（ESI）表征。以1a和2a的合成为例,优化了合成反应条件。结果表明：在最优条件（Cs₂CO₃ 20 mol%, EtOH为溶剂,于80 ℃反应120 min）下,1a和2a收率分别为90%和87%。     

取代四氢咪唑并[1,2-a]吡啶酮类化合物的合成

在三乙胺催化下,α-肉桂酰基烯酮二苄硫缩醛与乙二胺反应形成α-羰基-N,N-缩烯酮类化合物,其进一步发生分子内迈克尔加成反应,以中等产率合成了3个新型的取代四氢咪唑并[1,2-a]吡啶酮类化合物,其结构经1H NMR和IR表征.对反应机理进行了初步探讨.     

2-吡啶基咪唑并[1,2-a]吡啶的水中合成

2-乙酰基吡啶1经溴化反应后得到2-(2-溴乙酰基)吡啶氢溴酸盐2,2在水中与NaHCO3发生中和反应生成2-(2-溴乙酰基)吡啶,不经分离直接于水中和2-氨基吡啶衍生物3a-3h反应生成2-吡啶基咪唑并[1,2-a]吡啶4a-4h.采用核磁共振谱仪、红外光谱仪及质谱仪表征了产物的结构.结果表明,利用该方法可以在温和的反应条件下高产率得到目标产物,且方法操作简便、对环境友好.     

氨基磺酸催化下三组分一锅法无溶剂合成苯并[4,5]咪唑并[1,2-a]嘧啶类衍生物

无溶剂条件下,用氨基磺酸催化芳香醛,2-氨基苯并咪唑和β-二羰基化合物的三组分反应,简单而方便地得到了苯并[4,5]咪唑并[1,2-a]嘧啶类衍生物.该法具有产率高,成本低廉,环境友好,适应性广简捷方便等优点.     

新型噻唑并[3,2-a]嘧啶类化合物的合成

5-乙氧羰基-4-芳基-6-甲基-3,4-二氢嘧啶-2-酮与丁炔二酸二甲酯反应, 合成了系列新的噻唑并[3,2-a]嘧啶类化合物, 反应具有时间短、收率高、后处理简单等优点. 采用NMR (1H, 13C, COSY, HSQC和HMBC), IR等多种谱学技术, 结合元素分析对产物进行详细表征, 通过对目标产物的1,3-偶极环加成的衍生化产物进行X射线单晶衍射而确定目标产物的结构.     

新型噻唑并[3,2-a]嘧啶衍生物的合成及其抗肿瘤活性

以取代苯肼盐酸盐为原料,通过Vilsmeier-Haack,Biginelli和Knoevenagel等多步反应合成了9个含有吡唑取代基的噻唑并[3,2-a]嘧啶衍生物,并利用IR,1H NMR,13C NMR,ESI-MS和HRMS对目标化合物进行了结构表征.用四甲基偶氮唑盐(MTT)法测试了目标产物对人前列腺癌PC-3细胞和人肝癌Hep G2细胞的体外抗增殖活性,部分化合物表现出了较好的生物活性,其中化合物5b,5c,5g和5i对PC-3细胞的抗肿瘤活性优于阳性对照药5-氟尿嘧啶,IC50值分别为29.98,27.69,26.36和12.56μmol/L.进一步的研究表明,化合物5i能够诱导PC-3细胞凋亡,并使其周期阻滞在G2/M期.     

微波辐射下合成2-甲硫基-3-氰基-7-取代苯基吡唑并[1,5-a]嘧啶及生物活性的研究

利用取代烯胺酮1与3-甲硫基-4-氰基-5-氨基-1H-吡唑(2)反应,用传统和微波2种方法合成了6种化合物2-甲硫基-3-氰基-7-取代苯基吡唑并[1,5-a]嘧啶(3a～3f),化合物的结构均经元素分析,IR,1H NMR所证实.对比两种方法,微波辐射具有用时少、环境友好、易纯化和产率高的特点,同时,探讨了反应可能的机理,并对所有化合物的杀菌和除草活性进行了测试.     

5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶双杂环衍生物的合成与生物活性

以2-巯基-5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶为原料, 设计合成了17种含5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶环和1,2,4-三唑环的新型双杂环化合物, 结构经元素分析, MS, 1H NMR及13C NMR进行表征. 初步的生物活性测试表明, 部分化合物表现出较好的杀菌、除草活性.     

水介质中微波促进一锅法合成吡喃并[2,3-d]嘧啶衍生物

水相中将芳香醛、丙二腈和巴比妥酸以等摩尔比混合,微波辐射5~15 min,合成了9种7-氨基-6-氰基-5-芳基吡喃并[2,3-d]嘧啶二酮,产率为80%~92%,避免了传统合成法反应时间长和中间体分离的繁琐操作,减少了环境污染。 产物结构通过IR、¹H NMR和元素分析测试技术进行了表征。     

Polyethylene glycol-promoted synthesis of pyrimido[1,2-a]benzimidazole and pyrano[2,3-c]pyrazole derivatives in water

Synthesis of pyrimido[1,2-a]benzimidazole and pyrano[2,3-c]pyrazole derivatives were achieved using polyethylene glycol (PEG-400) as promoting reaction medium in water under catalyst-free conditions at reflux and room temperature, respectively. The structure of pyrimido[1,2-a]benzimidazole was confirmed using ¹H NMR, ¹³C NMR, DEPT, and HMBC experiments. The promising points for the present methodology are efficiency, generality, high yield, short reaction time, cleaner reaction profile, ease of product isolation, simplicity, potential of recycling reaction medium, and finally agreement with green chemistry protocols.     

Synthesis and Antimicrobial Activity of Some New 4H-Pyrrolo[1,2-a]benzimidazoles

Some new 4H-pyrrolo[1,2-a]benzimidazoles（2a-2f） have been synthesized. The structures of these compounds were confirmed by IR, tH NMR, mass spectroscopy and elemental analysis. Compound 2a was further confirmed by X-ray diffraction. The in vitro antimicrobial activities of these compounds were determined against some gram-positive bacteria, gram-negative bacteria and fungi and their drug-resistant isolates in comparison with standard drugs. Antimicrobial results indicate that compounds 2c, 2d and 2e show moderately active antibacterial properties, their minimum inhibitory concentrations are from 12.5 μg/mL to 125 μg/mL. In the series, the most active compound against C. albicans is compound 2fwith an MIC value of 31.25 μg/mL.     

Synthesis and anti-inflammatory activity of imidazo [1,2-a] pyrimidine derivatives

A series of imidazo[1,2-a]pyrimidine derivatives substituted adjacently with two aryls at positions 2 and 3 were designed and synthesized in order to improve their anti-inflammatory activities. Biological tests suggested that these compounds have antiinflammatory activities with COX-2 selectivity to some extent.     

Microwave Irradiation for Accelerating Synthesis of 5,6-Diphenylimidazo[1,2-a]pyrimidines Based on Isoflavones

Microwave irradiation was used to accelerate the cyclocondensation of isoflavones with 2-aminoimidazole to synthesize 5,6-diphenylimidazo[1,2-a]pyrimidines. A series of 17 new compounds were characterized by Fourier transform infrared, NMR, and elemental analysis. 5-(2-Hydroxyl-4-isopropoxyphenyl)-6-phenylimidazo-[1,2-a]pyrimidine was determined by x-ray diffraction. A variety of substrates can participate in the process with good yields and purities, making this methodology suitable for library synthesis in drug discovery.      

Versatility of Alternative Reaction Media: Water-Mediated Domino and Green Chemical Synthesis of Pyrimido[1,2-a]benzimidazole Under Nonconventional Conditions

A convenient and clean water-mediated synthesis of a series of 4-amino-2-aryl-1,2-dihydro pyrimido[1,2-a]benzimidazoles (4) is reported using alternative nonconventional energy sources. The products are obtained in shorter times with excellent yields (78–89%) from the multicomponent reaction of 2-aminobenzimidazole (1), malononitrile/ethylcyanoacetate (2a/b), and carbonyl compounds (3). The reaction is found to be general with respect to the cyclic and acyclic carbonyl compounds. The procedure does not involve the use of any additional reagent/catalyst, produces no waste, and represents a green synthetic protocol with high atom economy.     

Efficient One-pot Synthesis of Pyrrolo[2,1-a]isoquinoline and Pyrrolo[1,2-a]quinoline Derivatives

A one-pot sequential reaction for efficient synthesis of pyrrolo[2,1-a]isoquinoline and pyrrolo[1,2-a]-quinoline derivatives has been developed. The reaction included firstly the Cu-catalyzed three-component reaction of isoquinoline(quinoline), acetylenedicarboxylate and alkynylbenzene and then Cs₂CO₃-promoted intramolecular cyclization reaction of initially formed 1-alkenyl-2-alkynyl-1,2-dihydroisoquinoline(1,2-dihydroquinoline).     

微波作用下3-取代-(1H)-嘧啶［1，2-a］喹啉-1-酮的一步合成法

5-(双甲硫基亚甲基 ) -2 ,2 -二甲基 -1 ,3 -二环己 -1 ,4-二酮 (1 ) [1] 既具有丙二酸亚异丙酯的环状结构 ,又具有乙烯基硫代缩酮的结构特征 .它是一种多功能的合成试剂 ,其最重要性质是可与多种亲核试剂发生加成反应 ,继而消除甲硫基 ,从而可以转变成一系列有用的合成中间体 (2 ) [2～ 5] .若亲核试剂具有两个亲核部位 Nu1及 Nu2 ,则 Nu1反应后 ,Nu2可进一步与丙二酸亚异丙酯的羰基进行分子内的亲核加成 ,从而形成环状化合物 (3 ) ,这一模式已在多种杂环化合物合成中获得应用[6～ 8] .Me SMe SOOMe OOMe　+ Nu1-Nu Me SNu1Nu …