New regio/chemoselective synthesis of hydrogenated imidazo[1,5-b]pyridazines

The cascade heterocyclization of 1,2-diamino-4-phenyl-imidazole with ethyl 2-arylidene-2-cyanoacetates affords 1,2,3,4-tetrahydroimidazo[1,5-b]pyridazine-3-carbonitrile derivatives as mixtures of diastereomers. The experimental data and quantum chemical calculations were used to propose processes. The three-component processing with above-mentioned diamine, ethyl cyanoacetate and aromatic aldehydes leads to the same products in generally lower yields.     

Nicotinic acid-supported cobalt ferrite-catalyzed one-pot synthesis of substituted chromeno[3,4-b]quinolines

One-pot synthesis of substituted chromeno[3,4-b]quinoline derivatives was developed by three-component reaction of aldehydes, dimedone or 1,3-cyclohexadione, and 4-aminocoumarin in the presence of nicotinic acid-supported cobalt ferrite [CoFe₂O₄@SiO₂@Si(CH₂)₃Cl@NA] as a novel magnetic catalyst in chloroform at reflux conditions. Nicotinic acid-supported cobalt ferrite was characterized via Fourier transform infrared spectroscopy, X-ray diffraction, thermal gravimetric analysis, scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and vibrating sample magnetometry. Moreover, the catalyst could be easily recovered by magnetic separation and recycled up to five times without significant loss of its catalytic activity. The products formed in excellent yields over appropriate reaction times under environmentally friendly conditions. High efficiency and easy isolation of the catalyst from products by simple magnetic attraction are some of the considerable advantages of this procedure.     

A facile and convenient synthesis of novel imidazo[1,2-b] isoxazoles and their Mannich bases as potential biodynamic agents

A series of novel imidazo[1,2-b]isoxazoles 3 and their Mannich bases 4–6 were synthesized via convenient reactions. The reaction of 3-aminoisoxazole 1 with substituted phenacyl bromides 2 in dry ethanol afforded the corresponding 6-methyl-3-aryl imidazo[1,2-b]isoxazoles 3 in good yields.Compounds 3 on treatment with 37% formaline and secondary amines furnished the corresponding novel Mannich bases viz., 6-methyl-3-aryl-2-(morpholine/pyrrolidin-1-yl/piperidin-1-yl)-methyl-imidazo[1,2-b]isoxazoles 4–6.     

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.     

Ni(II), Co(II), and Cu(II) complexes incorporating 2-pyrazinecarboxylic acid：Synthesis,characterization, electrochemical evaluation,and catalytic activity for the synthesis of 2H-indazolo[2,1-b]phthalazine-triones

Three complexes containing 2-pyrazinecarboxylate (pzca–), including [Ni(pzca)2(H2O)2], [Co(pzca)2(H2O)2], and [Cu(pzca)2(H2O)2], have been synthesized and characterized using physico-chemical and spectroscopic methods. Furthermore, the structure of each complex was determined by single-crystal X-ray diffraction. All three complexes have an octahedral geometry, where the metal ion chelated by two carboxylate oxygens, two nitrogen atoms belonging to pyrazinic acid molecules, and two oxygen atoms of two water molecules. The catalytic activities of these complex-es were also investigated in the green synthesis of 2H-indazolo[2,1-b]phthalazine-triones by the reaction of hydrazine hydrate with an arylaldehyde, phthalic anhydride, and dimedone in acetic acid.     

New cascade reaction of azides with malononitrile dimer to polyfunctional [1,2,3]triazolo[4,5-b]pyridine

A new cascade reaction of azides with malononitrile dimer yielding polyfunctional [1,2,3]triazolo[4,5-b]pyridine was found. It was established that during the reaction of aryl azides with malononitrile dimer, under base catalysis, the formed intermediate triazole underwent spontaneous cyclization leading to the pyridine ring annulation. The obtained products have provided a new entry to [1,2,3]triazolo[4,5-b]pyridine.     

One-Pot Synthesis of Tetraarylpyrrolo[3, 2-b]pyrrole Dopant-Free Hole-Transport Materials for Inverted Perovskite Solar Cells

Four organic small-molecule hole transport materials ( D41 , D42 , D43 and D44 ) of tetraarylpyrrolo[3, 2-b]pyrroles were prepared. They can be used without doping in the manufacture of the inverted planar perovskite solar cells. Tetraarylpyrrolo[3, 2-b]pyrroles are accessible for one-pot synthesis. D42 , D43 and D44 possess acceptor-\begin{document}$ \pi $\end{document}-donor-\begin{document}$ \pi $\end{document}-acceptor structure, on which the aryl bearing substitutes of cyan, fluorine and trifluoromethyl, respectively. Instead, the aryl moiety of D41 is in presence of methyl with a donor-\begin{document}$ \pi $\end{document}-donor-\begin{document}$ \pi $\end{document}-donor structure. The different substitutes significantly affected their molecular surface charge distribution and thin-film morphology, attributing to the electron-rich properties of fused pyrrole ring. The size of perovskite crystalline growth particles is affected by different molecular structures, and the electron-withdrawing cyan group of D42 is most conducive to the formation of large perovskite grains. The D42 fabricated devices with power conversion efficiency of 17.3% and retained 55% of the initial photoelectric conversion efficiency after 22 days in dark condition. The pyrrolo[3, 2-b]pyrrole is efficient electron-donating moiety for hole transporting materials to form good substrate in producing perovskite thin film.      

哌啶并[2,3-b]哌嗪类衍生物的设计、合成及其抗血小板聚集活性研究

以2,3-二氨基吡啶和2,3-丁二酮为起始原料,经环化、催化氢化和亲核取代反应合成了10个新型哌啶并[2,3-b]哌嗪类衍生物(3a~3j),其结构经¹H NMR、¹³C NMR和HR-MS确证。体外抗血小板聚集活性研究表明,化合物3d、3e、3g、3h和3j具有一定的抗血小板聚集作用,其中化合物3h(IC₅₀=1.24mmol/L)的活性显著优于母体化合物川芎嗪(IC₅₀=3.96mmol/L)和阳性药物阿司匹林(IC₅₀=2.41mmol/L)。     

Synthesis and Tuberculostatic Activity of 1,3-Thiazacycloalkyl[3,2-b]-1,2,4-triazoles

The 4-hydroxyalkyl-1,2,4-triazole-3-thiones cyclization allowed us to work out the effective method of 1,3-thiazacycloalkyl[3,2-b]-1,2,4-triazoles synthesis. Some of the compounds that were obtained were tested for their tuberculostatic activity.     

Synthesis of 1,3-Bis[(3-aryl)-S-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]benzenes

1,3-bis[(3-aryl)-s-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]benzenes 2 were synthesized in high yields by the reaction of 3-aryl 4-amino-5-mercapto-1,2,4-triazole 1 with m-phthalic acid.