分子碘催化合成吡唑并[3，4-b]吡啶衍生物的研究

以色酮类化合物和1，3一二取代5-氨基吡唑化合物为原料，在分子碘催化下制备一系列新颖的多取代吡唑【3，4-b】吡啶衍生物（3a-3j），收率高达85％-92％，所有化合物的结构经^1HNMR和MS等表征。     

4-H-吡唑[1,5-a]苯并咪唑的合成

以2-卤苯胺和乙氧基亚甲基丙二腈为原料通过重氮化、酰化和碱性环合得到1-芳基-4-氰基-5-胺基吡唑,再经过Ullmann偶联制得标题化合物。产物结构经1HNMR、13CNMR、IR和元素分析表征。     

Studies on aminoazoles: Synthesis of Pyrazolo[1,5-a]-pyrimidines and their aza derivatives

The reaction of 4-arylazo-3-aminopyrazol-5-ones ( 1a – i ) with α,β-unsaturated nitriles, active methylene reagents and nitrile imines are reported. They lead to new polyfunctional derivatives of pyrazolo[1,5-a]pyrimidine ( 5a – c , 6 , 10a – i , 13a – c , 14a – c , 17a – d , 15 ), pyrazolo-[5,1-c]-1,2,4-triazine ( 22a – i ) and pyrazolo[5,1-c]-1,2,4-triazole ( 25a – c ). The structures of these products and the mechanisms of their formation are reported.     

碘催化Gr(o)ebke反应合成3-氨基咪唑并[1,2-a]吡啶衍生物

以芳香醛、2-氨基吡啶和异腈为原料,10 mol％分子碘作催化剂,甲醇作溶剂,回流反应3h合成标题化合物.该反应条件温和,产率为76％ ～90％,相应的结构经过红外、核磁共振和质谱表征确认.     

α,β-Unsaturated nitriles in heterocyclic synthesis. II. Synthesis of Pyrazolo[3,4-b]pyridine and Pyrazolo[1,5-a]pyrimidine derivatives of antipyrine

5-Amino-3-antipyrinyl-pyrazole ( 1 ) reacted with cinnamonitriles 2a and 2c , d to afford 5-amino-4-benzylidene-pyrazole derivatives 3a , b . Compound 1 reacted with two moles of 2a to yield pyrazolo[3,4-b]pyridine derivative 7a which could be also obtained from the reaction of 3a with 2a . The reaction of 1 with α-cyanochalcone 2e resulted in the formation of pyrazolo-[1,5-a]pyrimidine derivative 8 .     

Exploration of Pyrazolo[1,5-a]pyrimidines as Membrane-Bound Pyrophosphatase Inhibitors

Inhibition of membrane-bound pyrophosphatase (mPPase) with small molecules offer a new approach in the fight against pathogenic protozoan parasites. mPPases are absent in humans, but essential for many protists as they couple pyrophosphate hydrolysis to the active transport of protons or sodium ions across acidocalcisomal membranes. So far, only few nonphosphorus inhibitors have been reported. Here, we explore the chemical space around previous hits using a combination of screening and synthetic medicinal chemistry, identifying compounds with low micromolar inhibitory activities in the Thermotoga maritima mPPase test system. We furthermore provide early structure-activity relationships around a new scaffold having a pyrazolo[1,5-a]pyrimidine core. The most promising pyrazolo[1,5-a]pyrimidine congener was further investigated and found to inhibit Plasmodium falciparum mPPase in membranes as well as the growth of P. falciparum in an ex vivo survival assay.     

5-苄基-4,5,6,7-四氢吡唑并[1,5-a]哌嗪的合成

以炔丙醇和重氮甲烷为原料,经缩合、氧化、还原氨化、氯代及环合等5步反应,合成5-苄基-4,5,6,7-四氢吡唑并[1,5-a]哌嗪这一未见文献报道的化合物。产物结构经核磁共振氢谱和质谱确证。     

钯催化脱羧偶联环化反应合成2-取代吡唑并[1,5-a]吡啶类化合物

在Pd Cl2/PPh3催化条件下,N-氨基吡啶盐和取代丙炔酸反应,合成了6个2-取代吡唑并[1,5-a]吡啶类化合物。考察了不同催化剂、配体、溶剂和碱等因素对反应的影响,获得优化反应条件:Pd Cl2/PPh3作催化体系,碳酸钾作碱,二氯甲烷为溶剂,80℃下反应24 h,收率为59%~77%。     

GABAA Receptor Modulators with a Pyrazolo[1,5-a]quinazoline Core: Synthesis,Molecular Modelling Studies and Electrophysiological Assays

As a continuation of our study in the GABA_A receptor modulators field, we report the design and synthesis of new 8-chloropyrazolo[1,5-a]quinazoline derivatives. Molecular docking studies and the evaluation of the ‘Proximity Frequencies’ (exploiting our reported model) were performed on all the final compounds (3, 4, 6a–c, 7a,b, 8, 9, 12a–c, 13a,b, 14–19) to predict their profile on the α1β2γ2-GABA_AR subtype. Furthermore, to verify whether the information coming from this virtual model was valid and, at the same time, to complete the study on this series, we evaluated the effects of compounds (1–100 µM) on the modulation of GABA_A receptor function through electrophysiological techniques on recombinant α1β2γ2L-GABA_A receptors expressed in Xenopus laevis oocytes. The matching between the virtual prediction and the electrophysiological tests makes our model a useful tool for the study of GABA_A receptor modulators.     

5-甲基-N-芳基-1，2，4-三唑[1，5-a]嘧啶-2-磺酰胺的合成

以4个N-芳基-5-氨基-1,2,4-三唑-3-磺酰胺为原料,分别与4,4-二甲氧基-2-丁酮在碱性水溶液中环合,制得4个5-甲基-N-芳基-1,2,4-三唑[1,5-a]嘧啶-2-磺酰胺衍生物,并比较了4,4-二甲氧基-2-丁酮的合成路线,所有目标产物的结构均经IR和1HNMR谱验证.     

Heterocyclic synthesis with nitriles: Syntheses of some novel pyrazolo[1,5-a]pyrimidine and Pyrrolo[2′,3′:3,4]pyrazolo[1,5-a]pyrimidine Derivatives

3,5-Diamino-4-phenacylpyrazoles 1a , b react with the cinnamonitriles 2a , b to afford the novel 7-phenacylpyrazolo[1,5-a]pyrimidine derivatives 4a – d , respectively. Compounds 4c , d undergo cyclization with trichloroacetonitrile to afford the novel tricyclic system pyrrolo-[2′,3′:3,4]pyrazolo[1,5-a]pyrimidine derivatives 5e , f , respectively.     

Spectroscopic and In Silico Studies on the Interaction of Substituted Pyrazolo[1,2-a]benzo[1,2,3,4]tetrazine-3-one Derivatives with c-Myc G4-DNA

Herein we describe a combined experimental and in silico study of the interaction of a series of pyrazolo[1,2-a]benzo[1,2,3,4]tetrazin-3-one derivatives (PBTs) with parallel G-quadruplex (GQ) DNA aimed at correlating their previously reported anticancer activities and the stabilizing effects observed by us on c-myc oncogene promoter GQ structure. Circular dichroism (CD) melting experiments were performed to characterize the effect of the studied PBTs on the GQ thermal stability. CD measurements indicate that two out of the eight compounds under investigation induced a slight stabilizing effect (2–4 °C) on GQ depending on the nature and position of the substituents. Molecular docking results allowed us to verify the modes of interaction of the ligands with the GQ and estimate the binding affinities. The highest binding affinity was observed for ligands with the experimental melting temperatures (T_ms). However, both stabilizing and destabilizing ligands showed similar scores, whilst Molecular Dynamics (MD) simulations, performed across a wide range of temperatures on the GQ in water solution, either unliganded or complexed with two model PBT ligands with the opposite effect on the T_ms, consistently confirmed their stabilizing or destabilizing ability ascertained by CD. Clues about a relation between the reported anticancer activity of some PBTs and their ability to stabilize the GQ structure of c-myc emerged from our study. Furthermore, Molecular Dynamics simulations at high temperatures are herein proposed for the first time as a means to verify the stabilizing or destabilizing effect of ligands on the GQ, also disclosing predictive potential in GQ-targeting drug discovery.     

2-[4-(4-氟苄基)哌嗪-1-基甲基]吡唑并[1,5-a]吡啶的合成及其体外受体结合分析

以吡唑并[1,5-a]吡啶-2-甲醛和N-甲酰基哌嗪为原料,经过还原胺化反应、水解反应、N-烷基化反应,合成了2-[4-(4-氟苄基)哌嗪-1-基甲基]吡唑并[1,5-a]吡啶,总收率29.5%,用1HNMR、19FNMR、ESI-MS对中间体及目标化合物进行了结构表征,并通过体外受体结合实验,测定目标化合物对多巴胺D4受体的亲和常数为1.2nmol/L,对D2、D3受体的亲和常数分别为3 900、1 890 nmol/L,显示对多巴胺D4受体具有较高的亲和性与选择性,是一种潜在的多巴胺D4受体配基。     

4,5,6,7-四氢吡唑并[1,5-a]哌嗪-3-甲酸乙酯的合成

以4-氯-3-氧代丁酸乙酯为原料,经与叔丁醇钾醚化、DMF-DMA缩合、水合肼环合、脱叔丁基、羟基氧化、还原氨化、分子内环合以及氢化脱苄等反应合成了标题化合物。并对其中关键的羟基氧化反应和分子内环化反应的工艺条件进行了优化,获得了较优的工艺条件:在羟基氧化反应中以二氧化锰为氧化剂、氯仿为溶剂;在分子内环化反应中以甲基磺酰氧基(OMs)为离去基团。目标化合物的总收率为39.5%,其结构经~1HNMR、~(13)CNMR、MS和元素分析进行了确定。     

5-羟基-1,3,4-噻二唑[3,2-a]并嘧啶-7-酮衍生物的绿色合成

为了寻找干扰嘌呤核酸代谢的抗肿瘤新药,设计和合成了嘌呤生物碱的类似物。以2-氨基-1,3,4-噻二唑、丙二酸与三氯氧磷为原料,经过关环,偶合等反应合成了9种5-羟基-1,3,4-噻二唑[3,2-a]并嘧啶-7-酮衍生物,通过元素分析、IR、1 H NMR和质谱分析确定了其结构。     

One-Pot Multicomponent Synthesis of Pyrazolo[3,4-d]pyrimidine-6-one Derivatives

An environmentally benign, simple, and efficient procedure has been developed for the one-pot multicomponent synthesis of pyrazolo[3,4-d]pyrimidine-6-one derivatives by the reaction of the variety of aryl-aldehydes, 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one, and urea in the presence of catalytic amount of poly(N-vinylpyridinium) hydrogen sulfate in glycerol. The present method affords non-toxic and non-corrosive medium, short reaction times, high yield of the products, mild reaction conditions as well as simple experimental and isolation procedures. The catalyst can be recycled by simple filtration and reused without any significant reduction in its activity.     

三唑并嘧啶磺酰胺类化合物的合成及除草活性

以5-氨基-3-巯基-1,2,4-三唑为起始原料,经氧氯化、胺解和环合,制得了9个1,2,4-三唑[1,5-a]嘧啶磺酰胺类化合物,产物结构经IR和1H NMR验证,并测定了它们的除草活性。     

吡唑并[1,5-a]吡啶-5-羧酸的合成改进

以4-吡啶甲酸为原料,经过还原反应、羟基的保护、氮的氨基化、1,3-偶极体环加成反应,脱羧反应和高锰酸钾的氧化反应,最终得到目标产物吡唑并[1,5-a]吡啶-5-羧酸。该合成方法原料价格便宜,操作简单,对设备复杂性要求低,反应所需溶剂毒性小,工艺路线缩短。