Synthesis of Some New Thiazoles and Pyrazolo[1,5-a]pyrimidines Containing an Antipyrine Moiety

Ethyl 2-{2-[4-(2,3-dimethyl-5-oxo-1-phenyl-3-(pyrazolin-4-yl)]-2-cyano-1-(phenylamino)vinylthio}-acetate, 2-[4-(2,3-dimethyl-5-oxo-1-phenyl-(3-pyrazolin-4-yl))(1,3-thiazol-2-yl)]2-(4-oxo-3-phenyl-(1,3-thiazoilidin-2-ylidene))ethanenitrile, 2-[4-(2,3-dimethyl-5-oxo-1-phenyl(3-pyrazolin-4-yl))(1,3-thiazol-2-yl)]-2-(4-methyl-3-phenyl(1,3-thiazolin-2-ylidene))ethanenitrile, 2-(5-acetyl-4-methyl-3-phenyl(1,3-thiazolin-2-ylidene))-2-[4-(2,3-dimethyl-5-oxo-1-phenyl(3-pyrazolin-4-yl))(1,3-thiazol-2-yl)]ethanenitrile, and ethyl 2-(cyano(4-(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl)thiazol-2-yl)methylene)-2,3-dihydro-4-methyl-3-phenylthiazole-5-carboxylate were synthesized by treatment of 2-(4-(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl)thiazol-2-yl)-3-mercapto-3-(phenylamino)-acrylonitrile with appropriate halo ketones or halo esters. Also, 4-{2-[5,7-dimethyl-2-(phenylamino)(7a-hydropyrazolo[1,5-a]pyrimidin-3-yl](1,-thiazol-4-yl)}-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one derivatives were synthesized via reaction of 4-{2-[5-amino-3-(phenylamino)pyrazolin-4-yl](1,3-thiazol-2-yl)}-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one with β-diketone or β-keto ester. All synthesized compound were established by elemental analysis, spectral data, and alternative synthesis whenever possible.     

Synthesis and Antimicrobial Activity of Some New 5-Arylazothiazole,Pyrazolo[1,5-a] Pyrimidine, [1,2,4]Triazolo[4,3-a]Pyrimidine,and Pyrimido[1,2-a]Benzimidazole Derivatives Containing the Thiazole Moiety

1-(2-(4,5-Dihydro-3-(4-methyl-2-phenylthiazol-5-yl)-5-phenylpyrazol-1-yl)-4-substituted thiazol-5-yl)-2-phenyldiazene were synthesized from hydrazonoyl halides and 3-(4-methyl-2-phenyl-1,3-thiazol-5-yl)-5-phenyl-4,5-dihydro-1H-pyrazole-1-carbothioamide in ethanolic triethylamine. Also, pyrazolo[5,1-a]pyrimidines, 2,3,6-trisubstituted pyridines, and pyrazolo[3,4-d]pyridazines were obtained from sodium salt of 3-hydroxy-1-(4-methyl-2-phenylthiazol-5-yl)prop-2-en-1-one and different heterocyclic amines. All structures of the newly synthesized compounds were elucidated by elemental analysis, spectral data, and alternative synthetic route whenever possible. The newly synthesized compounds were tested towards different microorganisms.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis and Antiproliferative Activity of Novel [1,2,4]Triazolo[1,5-a]pyrimidine-7-amine Derivatives

A series of novel N-anilino-2-substituted-5-methyl-[1,2,4]triazolo[1,5-a]pyrimidine-7-amine derivatives was prepared and evaluated for their in vitro antiproliferative activity against two cancer cell lines,Bel-7402 and HT-1080.Most of the compounds inhibited the cell proliferation at a low concentration.Seven compounds,VI5,VI7,VI10,and VI12―VI15,possessed marked antiproliferative activity superior to that of cisplatin.Of these seven initial hits,compound VI10 was the most active.     

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.     

新型吡唑并[1,5-a]嘧啶-氮芥衍生物的设计、合成及抗肿瘤活性研究

吡唑并嘧啶是一类具有广泛生物活性的杂环结构母体,同时,氮芥类药物被广泛应用于临床治疗癌症.本文基于药物设计的拼合原理,以简单易得的原料制备了取代吡唑并[1,5-a]嘧啶中间体,通过将其与苯胺氮芥组分进行拼接,合成了一系列新型吡唑并[1,5-a]嘧啶-氮芥化合物,并评估了目标化合物对五种不同肿瘤细胞(HepG2、SH-S...     

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.     

Copper(I)-Catalyzed Tandem Cyclization/Condensation Reaction to Novel 4,5-Dihydropyrazolo[1,5-a]quinolines and Pyrazolo[1,5-a]indoles

A facile copper(I)-catalyzed tandem reaction for the synthesis of 4,5-dihydropyrazolo[1,5-a]quinolines and pyrazolo[1,5-a]indoles is reported here. High efficiency and good yields are displayed in this transformation under mild reaction conditions.      

新型2-甲基-5-羟基-7-氨基-吡唑[1,5-a]并嘧啶衍生物的合成

以3-甲基-5-氨基-吡唑和氰乙酸乙酯为原料,合成了2-甲基-5-羟基-7-氨基-吡唑[1,5-a]并嘧啶(2);2与芳胺的重氮盐溶液反应,合成了7个新型的2-甲基-5-羟基-6-芳基偶氮-7-亚氨基-吡唑[1,5-a]并嘧啶衍生物,收率87%~93%,其结构经~1H NMR,IR和ESI-MS表征。     

Water-Mediated Selective Synthesis of Pyrazolo[1,5-a]quinazolin-5(4H)-ones and [1,2,4]Triazolo[1,5-a]quinazolin-5(4H)-one via Copper-Catalyzed Cascade Reactions

A convenient and sustainable synthesis of pyrazolo[1,5-a]quinazolin-5(4H)-ones and [1,2,4]triazolo[1,5-a]quinazolin-5(4H)-one through copper-catalyzed cascade reactions of 2-bromobenzoates with 1H-pyrazol-5-amines or 1H-1,2,4-triazol-5-amine under ligand-free conditions in water is presented. It is notable that aqueous medium turned out to be crucial for the chemoselective formation of the title compounds. Compared with literature protocols, this new method showed advantages such as simple and sustainable procedure, commercially available starting materials, and convenient reuse of the reaction medium together with the copper catalyst.     

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.     

Synthesis and Biological Evaluation of Novel 5,7-Diphenylimidazo[1,2-a]pyridine Derivatives

A series of novel 5,7-diphenylimidazo[1,2-a]pyridine derivatives was designed and synthesized. The in vitro cytotoxic activities of all the target compounds against human colorectal cancer（HT-29）, human lung can- cer（H460）, human gastric cancer（MKN45） and human breast cancer（MDA-MB-231） cell lines were evaluated. The pharmacological results indicated that most of the target compounds showed moderate to excellent activities against the tested cell lines. The most promising compound 4h（0.20, 0.006, 0.08, 0.021 μmol/L） was 2.6, 5.1, 3.6 and 21.9 times more active than EPC2407（0.52, 0.031, 0.29, 0.46 μmol/L） against HT-29, H460, MKN45 and MDA-MB-231 cell lines, respectively.     

Pyrazolo[1,5-a]pyrimidine-Dioxaborinine Hybrid Dyes: Synthesis and Substituent Effect in the Photophysical Properties

A novel family of pyrazolo[1,5-a]pyrimidine-dioxaborinine (PP-DB) hybrid dyes was synthesized by the direct construction of the dioxaborinine (DB) fragment on the pyrazolo[1,5-a]pyrimidine (PP) ring, which implies the formation of four new bonds in a one-pot manner. The dyes’ optical properties were investigated and compared with the starting pyrazolo[1,5-a]pyrimidines; a study evidencing large fluorescence quantum yields in products (φ_f up to 69 %) due to an intramolecular charge transfer (ICT) process from the PP core to a ring of DB (PP→DB) that is absent in precursors (φ_f=0.03–0.30). Time-dependent density functional theory (TD-DFT) calculations confirmed the fluorescence process involved in the novel dyes, where their ICT limits the non-radiative process due to the restricted rotation in the D−A system. The present work provides insight into how phenyl and DB ring incorporation impact the optical properties of this new group of hybrids dyes based on PP-DB.     

2-[4-(2-Thienyl)-1,3-thiazol-2-yl]ethanenitrile in Heterocyclic Synthesis of Biological Interist

Abstract

Thiazolylacetonitrile was used in the synthesis of coumarin, pyrazolo[4,3]pyrimidines, 1,3,4-thiadiazolines, aminothiophenes, and thiazoles in a good yields. Also, pyrazolo[4,5-d]triazolino[4,5-a]pyrimidines, pyrazolo[4,5-d]thiazolino[3,2-a]pyrimidines, and pyrazolo[4,5-d]tetrazolino[1,5-a]pyrimidines were synthesized from pyrazolo[4,5-d]pyrimidine. Structures of the newly synthesized were elucidated by elemental analysis, spectral data, and alternative synthesis routes whenever possible. Some synthesized compounds were tested for their antimicrobial activity.     

Design,synthesis and antiproliferative activity of novel 2,7-disubstituted triazolo[1,5-a]pyrimidines

In our efforts to identify novel potent anticancer agents, we synthesized a series of 2,7-disubstituted triazolo[1,5-a]pyrimidines (6–16). Their antiproliferative activity against Bel-7402, HT-1080 and WI-38 cell lines was tested by MTT assay in vitro. Four of the compounds (9–11 and 16) displayed promising antiproliferative activity superior to gefitinib, especially compound 9. A preliminary SAR study of these derivatives was performed.     

Cyanoacetanilides Intermediates in Heterocyclic Synthesis,Part 3: Novel Syntheses of Thiazolinone and Thiazolo[3,2-a]Pyridine Derivatives

Thiazolo[3,2-a]pyridines 6a–c , 10 , 13 , and 14 have been synthesized via simple methods from the readily accessible 2-[N-(4-ethoxyphenyl)-acetamide-2-yl]-4,5-dihydro-4-thiazolinone 2. The structure of the synthesized compounds was established by analytical and spectral data.     

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。     

Synthesis of Some Pyrazolo[3, 4]pyrimidine Derivatives for Biological Evaluation

Abstract

A novel β -enaminonitrile of 1-(6-p-tolyl-pyridazin-3-yl)-pyrazole derivative 2 was formed using (6-p-tolyl-pyridazin-3-yl)-hydrazine ( 1 ) and 2-ethoxymethylenemalononitrile. The β-enaminonitrile derivative 2 was in turn used as a precursor for the preparation of pyrazoles ( 4 , 6 ), pyrazolo[3, 4-d]-pyrimidines ( 3 , 7–12 ) and pyrazolo[4, 3-e][1,2,4]triazolo[4,3-c]pyrimidine ( 13 ). Also, N- and S-acyclic nucleosides 14 and 15 were prepared. Some of the prepared products showed potent antimicrobial activity.     

Cyanoacetanilides Intermediates in Heterocyclic Synthesis. Part 5: Preparation of Hitherto Unknown 5‐Aminopyrazole and Pyrazolo[1,5‐a]pyrimidine Derivatives Containing Sulfamoyl Moiety

Novel 5‐aminopyrazole and pyrazolo[1,5‐a]pyrimidine derivatives have been synthesized from the readily accessible cyanoacetanilide derivative ( 2 ).     

Synthesis,Characterization, and Biological Evaluation of Some Novel Pyrazolo[5,1-b]thiazole Derivatives as Potential Antimicrobial and Anticancer Agents

The pharmacological activities of thiazole and pyrazole moieties as antimicrobial and anticancer agents have been thoroughly described in many literature reviews. In this study, a convenient synthesis of novel pyrazolo[5,1-b]thiazole-based heterocycles was carried out. The synthesized compounds were characterized by IR, ¹H and ¹³C NMR spectroscopy and mass spectrometry. Some selected examples were screened and evaluated for their antimicrobial and anticancer activities and showed promising results. These products could serve as leading compounds in the future design of new drug molecules.     

Azolo[1,5-a]pyrimidines and Their Condensed Analogs with Anticoagulant Activity

Hypercytokinemia, or cytokine storm, is one of the severe complications of viral and bacterial infections, involving the release of abnormal amounts of cytokines, resulting in a massive inflammatory response. Cytokine storm is associated with COVID-19 and sepsis high mortality rate by developing epithelial dysfunction and coagulopathy, leading to thromboembolism and multiple organ dysfunction syndrome. Anticoagulant therapy is an important tactic to prevent thrombosis in sepsis and COVID-19, but recent data show the incompatibility of modern direct oral anticoagulants and antiviral agents. It seems relevant to develop dual-action drugs with antiviral and anticoagulant properties. At the same time, it was shown that azolo[1,5-a]pyrimidines are heterocycles with a broad spectrum of antiviral activity. We have synthesized a new family of azolo[1,5-a]pyrimidines and their condensed polycyclic analogs by cyclocondensation reactions and direct CH-functionalization and studied their anticoagulant properties. Five compounds among 1,2,4-triazolo[1,5-a]pyrimidin-7-ones and 5-alkyl-1,3,4-thiadiazolo[3,2-a]purin-8-ones demonstrated higher anticoagulant activity than the reference drug, dabigatran etexilate. Antithrombin activity of most active compounds was confirmed using lipopolysaccharide (LPS)-treated blood to mimic the conditions of cytokine release syndrome. The studied compounds affected only the thrombin time value, reliably increasing it 6.5–15.2 times as compared to LPS-treated blood.