吡唑[1,5-a]并吡啶-3-羧酸衍生物合成方法的改进

以取代吡啶为原料,在羟胺-O-磺酸的作用下,得到取代的N-氨基吡啶的硫酸盐,再通过1,3-偶极环加成反应,与丙炔酸乙酯生成吡唑[1,5-a]并吡啶-3-羧酸乙酯衍生物,然后在质量分数30%的NaOH水溶液作用下水解成酸。 该方法将取代的N-氨基吡啶的硫酸盐直接投入到下步反应,省去传统方法中将硫酸盐转化为碘盐的步骤,解决了碘盐不易析出的问题,并将取代的N-氨基吡啶硫酸盐和丙炔酸乙酯分别用水和二甲基甲酰胺溶解后再混合,增加了原料和K₂CO₃在体系中的溶解性,提高了产率。 本文成功合成了6种化合物(4a~4f),产率为88%~93%,该方法条件温和,后处理简单,成本低,是适合大规模生产的新工艺。     

新型受体呋喃并[3’,4’:5,6]吡啶并[2,3-c]吡唑的合成及对阴离子的识别研究

设计并合成了5种呋喃并[3’,4’:5,6]吡啶并[2,3-c]吡唑受体分子, 利用紫外-可见吸收光谱考察了其与F－, Cl－, Br－, AcO－, 等阴离子的作用. 结果表明该类受体分子与阴离子形成氢键配合物, 导致呋喃并吡啶并吡唑受体的光谱发生变化. 测定了配合物的结合比和稳定常数, 发现受体化合物对F－, AcO－离子具有良好的选择性, 对其它多种阴离子无影响. Job曲线表明受体分子与阴离子间形成1∶1型的配合物.     

微波辐射下硅磺酸催化的香豆素并[4,3-d]吡唑并[3,4-b]吡啶的高效合成

在硅磺酸催化下,通过微波辐射的3-酰基香豆素与5-氨基吡唑的反应,一步高产率地合成了一系列香豆素并[4,3-d]吡唑并[3,4-b]吡啶衍生物.该方法具有反应时间短(20~30 min)、选择性好、产率高、操作简单和环境友好等优点.产物的结构经红外光谱、核磁共振谱及高分辨质谱予以确定.     

3-芳基-6-甲酰胺吡唑并[1,5-a]嘧啶类化合物的 合成及其抗癌活性研究

以乙酰乙酸乙酯和N,N-二甲基甲酰胺二甲缩醛为原料,通过缩合、环合、水解和酰胺化4步反应合成了一系列新的2,7-二甲基-3-芳基-6-甲酰胺吡唑并[1,5-a]嘧啶类化合物（6a~6f）,其结构经¹H NMR、 ¹³C NMR、 IR、 MS和元素分析。采用MTT法,以索拉菲尼(sorafenib)为阳性对照药,测定了化合物对人肝癌细胞株(HepG2)的体外抗增殖活性。结果表明：6a~6f具有一定的抗癌活性,其中化合物6a对人肝癌细胞株(HepG2)的抗增殖活性(IC₅₀=10.2 μmol·L^-1)和阳性对照药索拉菲尼(IC₅₀ = 7.9μmol·L^-1)相当。     

微波辐射促进的3-烷基取代咪唑并[1,5-a]吡啶合成

分别在常规加热和微波辐射条件下, 由双(2-吡啶甲酰)、二(2-吡啶)甲酮与脂肪醛及醋酸铵在醋酸溶剂中反应成功地制备了3-烷基取代的咪唑并[1,5-a]吡啶. 实验结果表明: 微波法比传统的合成方法产率高、反应时间短. 产物的结构经过¹H NMR, MS和元素分析表征.     

一个实用的碘催化的串联过程：利用醛来合成咪唑并[1,5-a]吡啶类化合物

咪唑并吡啶[1,5-a]类化合物是一类具有环合氮类的杂环化合物,在自然界中并不广存在. 但是近些年来的研究发现,这类杂环包括它的衍生物广泛地应用于光学材料和生物医药领域中. 我们选用吡啶苄胺和芳香醛作为反应底物,在碘和过氧叔丁醇催化下,反应能够得到咪唑并[1,5-a]吡啶类衍生物,而且我们研究当使用吡啶苄胺α位有取代基的底物时,也能够得到相应的目标产物. 因此,利用这种方法我们能同时制备得到 3-芳基化的咪唑并吡啶[1,5-a]类化合物和1,3-二芳基化的咪唑并[1,5-a]吡啶类化合物. 而且,该发展起来的方法具有操作简单,条件温和等特点.     

微波促进下6-氨基-4-芳基-5-氰基-3-甲基-1-苯基吡啶[2,3-c]并吡唑的合成

5-氨基-3-甲基-1-苯基吡唑与芳亚甲基丙二腈在少量乙二醇中, 经微波辐射得到6-氨基-4-芳基-5-氰基-3-甲基-1-苯基吡啶[2,3-c]并吡唑衍生物, 反应4～8 min完成, 产率为71%～90%, 产物结构通过红外、核磁共振、元素分析及单晶X射线分析表征.     

微波辐射下磷酸改性铌酸催化的香豆素修饰吡唑并[3,4-b]吡啶衍生物的高效合成

香豆素和吡唑并[3,4-b]吡啶骨架广泛存在于具有生物活性的天然化合物中,在药物化学中也被广泛用作药物核心单元,具有极其重要的作用.以磷酸改性铌酸作为催化剂,通过微波辐射下醛、香豆素衍生物、5-氨基吡唑的三组分反应一锅法高产率地合成一系列香豆素修饰的吡唑并[3,4-b]吡啶衍生物.该反应一步完成,具有催化剂和溶剂对环境友好,操作简单等优点.产物的结构经红外光谱、核磁共振谱及高分辨质谱予以确定.     

Cu催化新型苯并[e]吡唑并[1,5-c][1,3]噻嗪类化合物的合成

基于底物设计的概念,建立了一种以1-(2-溴芳基)-3-乙氧基-3-(取代胺基)-2-丙烯-1-酮(1)为原料,经由5-(2-溴芳基)-3-取代胺基-1H-吡唑(2)和异硫氰酸酯(3)在溴化亚铜/邻菲罗啉催化下高化学选择性地合成苯并[e]吡唑并[1,5-c][1,3]噻嗪类衍生物的新方法.该方法操作简单、反应条件温和且收率高.     

Pyrazolo[1,5-a]pyridines: synthetic approaches to a novel class of antiherpetics

Synthesis of a novel class of 7-amino-3-pyrimidinyl-pyrazolo[1,5-a]pyridine antiherpetic compounds is described. The synthetic methodology is designed to allow for rapid analog synthesis around the C-3 and C-7 positions of the pyrazolo[1,5-a]pyridine. The 7-chloropyrazolo[1,5-a]pyridine D, produced through an azirine rearrangement, served as a key building block. Two complementary methodologies for construction of the C-3 pyrimidine are described. These methods include the development of a novel cyclization utilizing alkynyl ketones or enones to give highly substituted pyrimidines. The outlined strategies facilitated late stage manipulation of either the C-3 or C-7 positions providing flexibility for rapid analog synthesis.     

Synthesis and structure of N-methylated azacalix[4]pyridines and azacalix[1]arene[3]pyridines

Reaction of azacalix[4]pyridine and azacalix[1]arene[3]pyridine with methyl iodide afforded N-methylated products selectively and highly efficiently. Crystal structures revealed that the modified electronic nature of the pyridines could change the conjugation between the bridging nitrogen and the neighbouring aromatics.     

Facile and Convenient Synthesis of Pyrazole,Pyridine, Pyridazine,Pyrazolo[3,4-b]pyridine,and Pyrazolo[5,1-c][1,2,4]triazine Derivatives

Abstract

A convenient synthesis of a series of pyrazole, pyridine, pyridinethione, pyridazine, pyrazolo[3,4-b]pyridine, imidazo[1,2-a]pyrimidine, and pyrazolo[5,1-c][1 Kumar , R. 5-(1-Substituted)alkyl pyrimidine nucleosides as antiviral (herpes) agents . Curr. Med. Chem. 2004 , 11 , 2749 – 2766 . [Google Scholar] 2 Holy , A. ; Günter , J. ; Dvoráková , H. ; Masojídková , M. ; Andrei , G. ; Snoeck , R. ; Balzarini , J. ; De Clercq , E. Structure–antiviral activity relationship in the series of pyrimidine and purine N-[2-(2-phosphonomethoxy)ethyl] nucleotide analogues, 1: Derivatives substituted at the carbon atoms of the base . J. Med. Chem. 1999 , 42 , 2064 – 2086 . [Google Scholar] 4 Brandes , W. ; Daum , W. ; Krauss , P. Fungicidal oxime ethers. Ger. Patent 2,623,847, 1977; Chem. Abstr . 1978 , 88 , 120822h . [Google Scholar]]triazine derivatives incorporating a pyrimidine moiety, via the reactions of the versatile, readily accessible 3-oxo-N-(pyrimid-2-yl)butanamide with the appropriate reagents, is described.     

Microwave-Assisted Sequential One-Pot Synthesis of 8-Substituted Pyrazolo[1,5-a][1,3,5]triazines

This paper reports a convenient sequential one-pot approach for the synthesis of an array of 14 pyrazolo[1,5-a][1,3,5]triazines, substituted in C8 by halogen (Br), various functions (CN and CO₂Et) and alkyl or (het)aryl groups. This study confirms the interest of combining the efficient heating obtained under dielectric microwave heating and the achievement of sequential one-pot reactions, avoiding the tedious work-up and purification of intermediate compounds, achieving sustainable synthesis processes. Considering usual conventional methods, this microwave protocol is featured by advantages in terms of yields, reaction times, and convenient gram scale synthesis.     

An Efficient Synthesis of Pyrazolo[3,4-b]pyridine Derivatives in Ionic Liquid

A series of 3-methyl-1,4,6-triaryl-1H-pyrazolo[3,4-b]pyridines was synthesized via the reaction of 3-methyl-1-phenyl-1H-pyrazol-5-amine and α,β-unsaturated ketones in ionic liquid without any catalyst. This protocol has the advantages of easier work-up, milder reaction conditions, high yields and environmentally benign procedure.     

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.     

Design, Synthesis, and Hypnotic Activity of Pyrazolo [1,5-a]pyrimidine Derivatives

On the basis of the Zaleplon structure, novel pyrazolo[1,5-a]pyrimidines were designed and prepared for studies on their hypnotic activity. This paper reported the synthesis of twelve new 5-methyl-7-substituted-pyrazolo[1,5-a]pyrimidine-3-carbonitrile derivatives by using simple starting materials such as propane dinitrile and triethyl orthoformate. The structures of the derived target compounds were confirmed by their IR and ^1H-NMR spectroscopic data. The preliminary pharmacological evaluations indicated that some compounds showed hypnotic activity, whilc derivative 1c was the most potent one.     

Synthesis and in vitro anticancer activity of pyrazolo[1,5-a]pyrimidines and pyrazolo[3,4-d][1,2,3]triazines

A novel series of pyrazolo[1,5-a]pyrimidines 14a–j and pyrazolo[1,5-a]quinazolines 18a, b were synthesized via condensation of 5-amino-1H-pyrazoles 10a, b with 3-(dimethylamino)-1-aryl-prop-2-en-1-ones 11a–e and 2-((dimethylamino)methylene)-5,5-dimethylcyclohexane-1,3-dione (15), respectively, in glacial acetic acid. Finally, treatment of 10a, b with sodium nitrite (NaNO₂) afforded pyrazolo[3,4-d]triazines 20a, b. Structures of compounds were confirmed by their spectral data. These compounds were screened for their in vitro cytotoxic activities against human cancer cell lines (HepG-2 and MCF-7) using 3-[4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The results reveal that, the compounds 14b and 14h were the most potent in comparison with doxorubicin. The structure–activity relationship was discussed.