Facile synthesis and characterization of novel bis(2-S-alkylpyridines) and bis(3-aminothieno[2,3-b]pyridines) incorporating 1,3-diarylpyrazole moiety

3-(4-Hydroxyphenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde (1) is condensed with acetophenone to afford the corresponding unsaturated carbonyl compound 4 whose potassium salt is reacted with 1,4-dibromobutane to afford the bis-unsaturated carbonyl compound 3. Both carbonyl compounds 3 and 4 are reacted with 2-cyanoethanethioamide, through Michael addition reaction followed by cyclocondensation, to prepare the starting materials bis(pyridine-2(1H)-thione) derivative 5 and pyridine-2(1H)-thione derivative 8. Two synthetic routes to synthesize the target materials 7 and 14 are described to get the most efficient method for preparation and maximum yield%. The first route came from the direct alkylation of the bis(pyridine-2(1H)-thione) derivative 5 using iodomethane (6a) and benzyl chloride (6b) to afford the corresponding bis(2-S-alkylpyridine) derivatives 7a,b. The reaction of 5 with halo-containing compounds 10a–d to synthesize the target materials bis(3-aminothieno[2,3-b]pyridine) derivatives 14a–d failed under various reaction conditions. The second route involves the reaction of pyridine-2(1H)-thione derivative 8 with 6a,b and 10a–d to afford the corresponding 2-S-alkylpyridine derivatives 9a,b and 3-aminothieno[2,3-b]pyridine derivatives 13a–d, through the formation of 2-S-alkylpyridine derivatives 12a–d followed by a Thrope-Ziegler reaction, whose potassium salts reacted with 1,4-dibromobutane to afford the corresponding target materials 7a,b and 14a–d, respectively. The structures of target molecules were elucidated using elemental analyses and spectral data.     

Synthesis of some novel 2-oxo-pyrano(2,3-b)- and 2-oxo-pyrido(2,3-b)quinoline derivatives as potential antimalarial,diuretic, clastogenic and antimicrobial agents

The 2-chloro-3-formyl quinoline derivatives ( 1a–e ) on treatment with acetic anhydride and sodium acetate, afforded the corresponding novel 2-oxo-pyrano(2,3-b) quinoline derivatives ( 2a–e ), and these were subjected to ammonia treatment to yield the corresponding naphthyridine derivatives ( 3a–e ). The prepared compounds ( 2a–e ) were tested for their antimalarial, diuretic, clastogenic and antimicrobial properties. Not all the compounds showed a diuretic effect and the significant increase in the frequency of micronuclei shows that they are non-clastogens, whereas the 7-chloro derivative ( 2e ) was a very effective antimalarial agent against the mosquito species. All the compounds were found to have optimum antimicrobial activity against Staphylococcus aureus, Escherichia coli and Salmonella typhi. Compounds 2d and 2e were found to be most active against the bacteria tested. © 1998 SCI     

Synthesis and antimicrobial activities of some ethyl 2-arylthio-6-arylimidazo[2,1-b]thiazole-3-carboxylates and their sulfones

A series of new 2-arylthio-3-ethoxycarbonyl-6-arylimidazo[2,1-b]thiazoles (4a–4h) and 2-arenesulfonyl-3-ethoxycarbonyl-6-arylimidazo[2,1-b]thiazoles (5a–5h) have been prepared and characterized by analytical and spectral methods. The title compounds 4a–4h and 5a–5h were obtained by the reaction of 2-amino-4-ethoxycarbonyl-5-arylthiothiazoles (2a and 2b)/2-amino-4-ethoxycarbonyl-5-arenesulphonyl-thiazoles (3a and 3b) with various phenacyl bromides in anhydrous ethanol. These newly synthesized compounds (4a–4h and 5a–5h) were screened for their antibacterial activity against Gram-negative bacterium Escherichia coli, Gram-positive bacterium Staphylococcus aureus, and antifungal properties against Aspergillus niger and Candida albicans.     

噻吩并[2,3-d]嘧啶类衍生物的合成及抗肿瘤活性

以2-丁酮、丙二腈和单质硫为原料，通过改良的Gewald反应合成2-氨基-3-氰基-4,5-二甲基噻吩，再与三氯氧磷和三氟乙酸反应“一锅法”合成关键中间体5,6-二甲基-2-三氟甲基-4-氯噻吩并[2,3-d]嘧啶，最后与取代苄胺发生取代反应制得16种噻吩并[2,3-d]嘧啶类含氟衍生物IIIa～IIIp。通过1HNMR、13CNMR、IR、MS和元素分析对目标化合物进行了表征，并经X射线单晶衍射测定了化合物IIIa的晶体结构。体外抗肿瘤活性结果表明，目标化合物IIIa、IIIc和IIIf表现出良好的抗肿瘤活性，苯环上被供电子基取代时目标化合物IIIk～IIIp的抗肿瘤活性均较差，苯环间位被吸电子基取代时活性较好（如IIIc、IIIf和IIIi），尤其是间位被氟原子取代时活性明显提高。化合物IIIa对MCF-7和HepG2细胞的半数抑制浓度（IC50）分别为2.01、2.44 μmol/L，IIIc对MCF-7和HepG2细胞的IC50分别为1.44、1.47 μmol/L，二者的活性均远优于对照组吉非替尼（Gefitinib）。     

2,3-二氢-2-苯基咪唑[2,1-b]苯并噻唑的合成研究

以2-氯苯并噻唑为原料,在N,N-二异丙基乙基胺存在下与D或L-苯甘氨醇反应后,不经分离直接与甲磺酰氯在N,N-二异丙基乙基胺作用下关环,一锅法合成了(R)或(S)-2,3-二氢-2-苯基咪唑[2,1-b]苯并噻唑,利用IR、~1HNMR、MS谱和旋光度对其结构进行了表征.通过优化研究2,3-二氢-2-苯基咪唑[2,1-b]苯并噻唑的合成工艺条件,可得到总收率为80%的(R)或(S)-2,3-二氢-2-苯基咪唑[2,1-b]苯并噻唑.     

MgO-CeO2 nanocomposite: efficient catalyst for the preparation of 2-aminothiophenes and thieno[2,3-d]pyrimidin-4(3H)-one derivatives

MgO-CeO₂ nanocomposite was prepared by a co-precipitation method and characterized by X-ray diffraction (XRD), FE-SEM, and particle size distribution analysis. The XRD pattern shows the cubic phase of cerium oxide as the dominate phase. FE-SEM images show the homogeneity distribution of magnesium and cerium oxides in the sample. The mean particle size of nanocomposite determined by the dynamic light scattering technique is 66?nm. The catalytic activity of MgO-CeO₂ nanocomposite was examined on the synthesis of 2-aminothiophenes and thieno[2,3-d]pyrimidin-4(3H)-one derivatives. In all cases, products were obtained in good to excellent yields.     

Reaction of hydrazonoyl halides 49 1: Synthesis and antimicrobial activity of some new pyrimido[1,2-b][1,2,4,5]tetrazin-6-one,tetrazino[3,2-b]quinazolin-5-one,pyrimidino[1,2-b]1,2,4,5-tetrazin-5-one and triazolo[4,3-a]pyrimidine derivatives

Pyrimido[1,2-b][1,2,4,5]tetrazin-6-one, tetrazino[3,2-b]quinazolin-5-one, pyrimidino[1,2-b]1,2,4,5-tetrazin-5-one and triazolo[4,3-a]pyrimidine derivatives were synthesized from C-(4-methyl-2-phenyl)thiazol-5-oyl-N-phenyl-hydrazonoyl bromide and different pyrimidine-2-thiones. New compounds had their structures confirmed by elemental and spectral analysis and were screened antimicrobial activity.     

Competent inhibitor for the corrosion of zinc in hydrochloric acid based on 2,6-bis-[1-(2-phenylhydrazono)ethyl]pyridine

A novel compound, 2,6-bis-[1-(2-phenylhydrazono)ethyl]pyridine (BPEP), was synthesized and confirmed by NMR and IR spectroscopy. BPEP was examined as an inhibitor for the corrosion of zinc electrode in 1.0 M HCl. The inhibition efficiency of BPEP was assessed through various techniques such as hydrogen evolution, galvanostatic polarization, potentiodynamic anodic polarization, and electrochemical impedance spectroscopy. The inhibiting action of BPEP was explained in terms of the formation of a stable complex between zinc ions and BPEP and then adsorbed onto the zinc surface. The formation of the complex was established by FT-IR spectroscopy. A conductometric titration indicated that the stoichiometry of Zn⁺²:BPEP (metal:ligand) is 1:1. The adsorption follows the Langmuir isotherm. The Galvanostatic polarization measurements have shown that the BPEP molecule acts as a mixed-type inhibitor. The pitting potential shifted in the noble direction, indicating that the inhibition of pitting corrosion of zinc in the presence of BPEP.The activation energy and themodyanamic parameters of the adsorption process were calculated and have been explained.     

One-pot three-component synthesis of 2H-thiopyrano[2,3-b]quinoline-2,3-dicarboxylates from 2-mercaptoquinoline-3-carbaldehydes,dialkyl acetylenedicarboxylates and Ph3P

An extremely concise one-pot procedure toward the synthesis of 2H-Thiopyrano [2,3-b]quinoline-2,3-dicarboxylates whose applications as medicines is predictable has been established. This approach produces three fused rings evolving from the formation of four new carbon–carbon bonds and a stereogenic center in a one-pot protocol.     

A convenient [hydroxy(tosyloxy)iodo]benzene-mediated one-pot synthesis of 2-arylimidazo[2,1-b]benzothiazoles

Several 2-arylimidazo[2,1-b]benzothiazoles (4) have been conveniently synthesized in one-pot reactions via α-tosyloxylation of enolizable ketones (1) using [hydroxy(tosyloxy)iodo]benzene 2 in acetonitrile, followed by treatment with 2-amino-6-(substituted)benzothiazoles (3). The present protocol offers several advantages towards general access of 2-arylimidazo[2,1-b]benzothiazoles, including an intriguing alternative to the literature protocols, a readily available nontoxic reagent, operational simplicity and an environmentally benign procedure.     

噻吩并[3,2-d]嘧啶-4(3H)-酮的合成工艺研究

报道了一种噻吩并[3,2-d]嘧啶-4(3H)-酮的简便、高效合成新工艺。巯基乙酸乙酯和2-氯丙烯腈在乙醇钠作用下进行环合制得3-氨基噻吩-2-甲酸乙酯,然后在乙酸乙酯中与氯化氢气体成盐进行分离。3-氨基噻吩-2-甲酸乙酯的盐酸盐直接与过量的甲酰胺关环制得噻吩并[3,2-d]嘧啶-4(3H)-酮,两步总产率约80%。     

2H-噻唑[3,2-b][1,2,4]三嗪-3,7-二酮的设计合成及生物活性

为寻找高活性的乙酰胆碱酯酶（AChE）抑制剂，以取代的苯甲醛和N-乙酰甘氨酸为原料经过五步反应合成了13个2H-噻唑[3,2-b][1,2,4]三嗪-3,7-二酮类化合物，目标化合物结构经1H NMR，13C NMR和HRMS确认。采用Ellman法测试了化合物在10 μmol/L浓度下对AChE的抑制活性，结果显示所有目标化合物均具有抑制活性，其中化合物6-(4-甲氧基苄基)-2-(4-甲氧基苯亚甲基)-2H-噻唑并[3,2-b]-1,2,4-三嗪-3,7-二酮（Ⅴk）活性最好，抑制率达到80.1%。通过分子对接研究了化合物Ⅴk和AChE的结合模式，Ⅴk可以跟AChE的多个催化位点结合。2H-噻唑[3,2-b][1,2,4]三嗪-3,7-二酮类化合物可以为开发具有自主知识产权的新型AChE抑制剂提供参考。     

头孢替安中间体N,N-二甲基氨基乙基-5-巯基-四氮唑的合成研究

N,N-二甲基氨基乙基-5-巯基-四氮唑（DMMT）为合成头孢替安的关键中间体。N,N-二甲基乙二胺与CS2加成后,不经巯基保护,直接与NaN3闭环合成得到产品,总收率达到75.4%。对实验条件进行了优化。     

Synthesis of some new fused thiopyrano[2,3-d]thiazoles and their derivatives

A series of some new fused thiopyrano[2,3-d]thiazole derivatives have been synthesized by a stereo-selective hetero-Diels-Alder reaction of 5-(2,4-dihydroxy-benzylidene)-4-thioxo-thiazolidine derivatives 3a,b with acrylonitrile, ethyl acrylate, N-phenylmale-imide, ω-nitrostyrene and N-phenyl-1, 3, 4-triazole-2,5-dione. 5-Amino-9-hydroxy-dihydro-benzopyrano[3′,4′:4,5]thiopyrano[2,3-d]thiazol-6-one derivatives 14a,b have been synthesized by Michael addition of 3a,b with malononitrile. Structures and conceivable mechanisms are discussed.     

2-氟-9,10-亚甲二氧基-6[H]-[1]苯并吡喃并[4,3-b]喹啉的合成与表征

以6-氟-色满酮-4为原料，与6-氨基胡椒醛发生Friedǎnder合反应而得到新的喹啉衍生物2-氟-9，10-亚甲二氧基-6[H]-[1]苯并吡喃并〔4，3-b]喹啉，其结构经IR、^1HNMR、MS和元素分析确证。     

薁并[2,1-b]吡啶的简便合成方法

以2-氨基-1-乙酰基薁-3-甲腈和β-二羰基化合物为原料,在1-甲基咪唑-3-丙基磺酸硫酸氢盐的作用下,一锅法合成了薁并[2,1-b]吡啶类衍生物。该反应收率良好、操作简单、条件温和。产物的结构通过红外光谱、核磁共振谱和元素分析证实。     

2-烷氨基-3-对氟苯基-5-甲基-6-(1H-1,2,4-三唑-1-基)-噻吩并[2,3-d]嘧啶-4(3H)-酮衍生物的合成及其杀菌活性

已见含氟类有机物具有杀菌能力的报道,将氟元素引入到噻吩并嘧啶酮的衍生物之中,考查其杀菌活性。通过Gewald反应生成噻吩,产物同PPh3、C2Cl6、Et3N作用得到膦亚胺,再用对氟苯基异氰酸酯与之作用得到碳二亚胺,之后与伯胺反应得到10种新的标题化合物,其结构经1HNMR、MS和元素分析表征。生物活性测试表明,此类衍生物对常见农作物部分菌体均表现出较大的抑制作用,其中以2-正庚氨基-3-对氟苯基-5-甲基-6-(1H-1,2,4-三唑-1-基)-噻吩并[2,3-d]嘧啶-4(3H)-酮活性最好,它对棉花枯萎菌的抑制率达90%。该系列物质相对不含氟元素的同种取代基的噻吩并嘧啶酮衍生物的杀菌活性有一定程度的提高。     

1-甲基-3-(7-氟-4-炔丙基-1,4-苯并噁嗪-3-酮-6-基)-1,3-喹唑啉-2,4-二酮的合成及其除草活性

标题化合物(SYP-298)是沈阳化工研究院的试验除草剂,由邻硝基苯甲酸经5步反应制得。其结构经核磁共振谱和质谱分析确证。SYP-298在温室条件下38 g a.i./hm2可防多种阔叶杂草,在600 g a.i./hm2对玉米和水稻安全。     

4-[2'-(反式-4-正丙基环己基)乙基]环己酮的合成

以反式-4-正丙基环己基甲酸和4-羰基环己基甲酸乙酯为原料,通过羧酸还原、溴代反应、羰基保护、酯还原、格氏反应、水解、醇脱水、加氢等8步反应合成了乙烷类液晶中间体4-[2’-(反式-4-正丙基环己基)乙基]环己酮,熔点34.56℃。并用气相-质谱(GC-MS)、红外光谱(IR)、核磁共振氢谱(1H NMR)确认了结构。     

聚酰乙基苯基次膦酰乙二胺的合成与表征

以羧乙基苯基次膦酸、乙二胺为原料,二甲苯为溶剂,合成膨胀型阻燃剂聚酰乙基苯基次膦酰乙二胺,其最适宜的工艺条件为羧乙基苯基次膦酸与乙二胺的摩尔比为1:1,在140℃下回流反应8h,产品得率为100.8%,用红外、核磁、元素分析仪、热分析仪等对产品结构进行表征,并对其阻燃性能进行了研究。