Spectroscopic characterization of halogen- and cyano-substituted pyridinevinylenes synthesized without catalyst or solvent

An efficient Knoevenagel route using green chemistry conditions was applied for the synthesis of halogen- and cyano- substituted pyridinevinylene compounds. Absorption and fluorescence emission spectra of these conjugated compounds were recorded and compared in order to evaluate the effect of substituents on the electronic properties of pyridinevinylene compounds. The substituents studied were terminal Cl and F, two or three aromatic rings, as well as a cyano group attached to a C=C double bond. The compounds synthesized are: (E)-2-(4-fluorostyryl)pyridine, (E)-2-(4-chlorostyryl)pyridine, (E)-4-(4-chlorostyryl)pyridine, 2,3-diphenylacrylonitrile, 3-phenyl-2-(pyridin-2-yl)acrylonitrile, 3-phenyl-2-(pyridin-3-yl)acrylonitrile, 2-phenyl-3-(pyridin-2-yl)acrylonitrile, 3,3′-(1,4-phenylene)bis(2-phenylacrylonitrile), 3,3′-(1,4-phenylene)bis(2-(pyridin-2-yl)acrylonitrile), and 3,3′-(1,4-phenylene)bis(2-(pyridin-3-yl)acrylonitrile). The solvent-free method used in this work allows obtaining each compound by controlling the reaction temperature. The compounds were characterized by infrared spectroscopy and 1H-NMR spectroscopy.     

3-Methoxypyrazoles from 1,1-dimethoxyethene,few original results

From the condensation between 1,1-dimethoxyethene and anhydrides, synthetically useful β,β–dimethoxy–α,β-unsaturated ketones were prepared. Upon addition of hydrazine, followed by iodination, 4-iodinated 3-methoxypyrazoles were obtained. The occurrence of a side compound also provided insights in the scope of this synthesis. In a second part, 1-(4-chlorophenyl)-3,3-dimethoxyprop-2-en-1-one was obtained from 1,1-dimethoxyethene and 4-chlorobenzoylchloride. The subsequent addition of hydrazine or phenylhydrazine led to 5-(4-chlorophenyl)-3-methoxy-1H-pyrazole or 1-phenyl-5-(4-chlorophenyl)-3-methoxypyrazole in unprecedented 64 or 54% overall yield. Unexpectedly, addition of 2-pyridylhydrazine led to the 2-([1,2,4]triazolo[4,3-a]pyridin-3-yl)-1-(4-chlorophenyl) ethanone. This led us to design original conditions, which led to the target 1-(2-pyridyl)-5-(4-chlorophenyl)-3-methoxypyrazole in a 39% overall yield. Additional examples are provided, starting from various carboxychlorides.     

新型苯并咪唑衍生物的合成及其抗凝血活性

以3-［(3-氨基-4-甲基氨基苯甲酰)吡啶-2-基氨基］丙酸乙酯为原料,与4-氰基-3-氟苯取代基乙酸经环化反应制得3-【【2-｛［(4-氰基-3-氟苯取代基）甲基］-1-甲基-1-H-苯并咪唑-5-基｝羰基】吡啶-2-基】氨基丙酸乙酯（3a, 3e）; 3经水解和酰胺化反应制得3-【【【2-｛［(4-氰基-3-氟苯基)取代基］甲基｝-1-甲基-1H-苯并咪唑-5-基】羰基】吡啶-2-基氨基】丙酰取代胺基（6a~6h）;6与乙酰氧肟酸经环合反应合成了8个新型的苯并咪唑衍生物（7a~7h）,其结构经1H NMR和HR-ESI-MS表征。抗凝血活性结果表明： 7a和7c的抗凝血活性最好,其aPTT值分别为(83.1±4.2) s和(80.7±2.9) s,优于阳性对照药达比加群酯(75.3±2.1)s。     

甲磺酸达比加群酯杂质的合成

根据甲磺酸达比加群酯工艺,合成了甲磺酸达比加群酯的7个杂质：3-【【【2-｛［(4-氰基苯基)氨基］甲基｝-1-甲基-1H-苯并咪唑-5-基】羰基】(吡啶-2-基)氨基】丙酸（A）, 3-【【【2-【｛［4-(乙氧基)叔胺基］苯基｝氨基】甲基】-1-甲基-1H-苯并咪唑-5-基】羰基】(吡啶-2-基)氨基】丙酸乙酯盐酸盐(B), 3-【【【2-【｛［(4-甲脒基)苯基］氨基｝甲基】-1-甲基-1H-苯并咪唑-5-基】羰基】(吡啶-2-基)氨基】丙酸乙酯盐酸盐(C), 3-【【【2-【【【4-｛［(己氧基)羰基］氨基亚甲胺基｝苯基】氨基】甲基】-1-甲基-1H-苯并咪唑-5-基】羰基】(吡啶-2-基)氨基】丙酸甲酯盐酸盐(D), 3-【【【2-【【【4-【｛［(己氧基)羰基］氨基｝羰基】苯基】氨基】甲基】-1-甲基-1H-苯并咪唑-5-基】羰基】(吡啶-2-基)氨基】丙酸乙酯(E), 3-【【【2-【【【4-【｛［(己氧基)羰基］氨基｝亚氨甲基】苯基】氨基】甲基】-1-甲基-1H-苯并咪唑-5-基】羰基】(吡啶-2-基)氨基】丙酸(F), (Z)-3-【【【2-【【【4-【｛［(N,N′-二己氧基)羰基］脒基｝亚氨甲基】苯基】氨基】甲基】-1-甲基-1H-苯并咪唑-5-基】羰基】(吡啶-2-基)氨基】丙酸乙酯(G),其结构经¹H NMR和ESI-MS确证。     

New platinum(II) and palladium(II) quinoline-imine-pyridine, quinoline-imine-thiazole and quinoline-imine-imidazole complexes by metal-assisted condensation reactions

Pt(II) and Pd(II) methyl- and chloro-complexes with the tridentate N-donor ligands ((pyridin-2-yl)methylene)quinolin-8-amine (NNPy), ((pyridin-2-yl)ethylidene)quinolin-8-yl-amine (NNMePy), (phenyl(pyridin-2-yl)methylene)quinolin-8-yl-amine (NNPhPy), ((thiazol-2-yl)methylene)quinolin-8-amine (NNTh) and ((imidazol-4-yl)methylene)quinolin-8-amine (NNImH) were prepared by metal-assisted condensation of 8-aminoquinoline and an ortho-substituted aldehydo- or keto- N-heterocycle. Preliminary reactivity studies involving the coordinated tridentate N-donors, the chloro-ligand and the M-CH₃ bond were carried out, leading to the synthesis of several new complexes. During these studies, the formation of a novel five-coordinate Pt(II) carbonyl-complex was observed.     

Synthesis and alkylation of new 3-functionally substituted carbo[c]fused pyridin-2-ones(thiones)

By condensation of 2-acyl-1-(morpholin-4-yl)cycloalkenes with CH-acids new 3-functuinally substituted carbo[c]fused pyridin-2-ones(thiones) were synthesized. N, 1-Diphenyl-5, 6, 7, 8-tetrahydroisoquinoline-3-thione under the action of acrylonitrile and alkyl halides suffered a selective S-alkylation.     

Microwave synthesis,characterization and antimicrobial study of new pyrazolyl-oxopropyl-quinazolin-4(3H)-one derivatives

Heterocyclic compounds containing pyrazolyl-oxopropyl-quinazolin-4(3H)-one are reported to possess significant biological activity. Syntheses of 6-bromo-2-(3-chloro-2-oxopropyl)-3-(4-fluorophenyl)quinazolin-4(3H)-one 2 6-bromo-3-(4-fluorophenyl)-2-(3-hydrazinyl-2-oxopropyl)quinazolin-4(3H)-one 3 and 6-bromo-2-(3-(3-(4-(1-(2-chlorophenyl)-3-methyl-1H-pyrazol-5(4H)-ylideneamino)phenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazol-1-yl)-2-oxopropyl)-3-(4-fluorophenyl)quinazolin-4(3H)-one 5a–j using microwave irradiation have been described. These compounds have been characterized on the basis of the UV, IR, ¹H NMR, ¹³C NMR, Mass and elemental analysis. Compounds have been evaluated for their antimicrobial activity.     

Zeolite-catalyzed synthesis of nicotinyl-fused indolo-pyrazoles and evaluation of their activities against Anopheles arabiensis and Lipoxygenase

A series of nicotyl-fused indolo-pyrazoles (NFIPs) were synthesized by a one-pot multicomponent reaction of aryl aldehydes, isoniazid, and indole in the presence of zeolite as a catalyst. Structures of all the synthesized compounds were established by IR, ¹H-NMR, ¹³C-NMR, 2D-NMR, TOF-MS, and elemental analysis. The products were obtained in excellent yields and high purity. All 10 compounds were screened for larvicidal and insecticidal properties against Anopheles arabiensis and tested for their lipoxygenase inhibitory activity. Compounds (3-(3-hydroxy-4-methoxyphenyl)-2,3-dihydropyrazolo[4,3-b]indol-1(4H)-yl)(pyridin-4-yl)methanone ( 4i ) and (3-(3-bromo-5-hydroxy-4-methoxyphenyl)-2,3-dihydropyrazolo[4,3-b]indol-1(4H)-yl)(pyridin-4-yl)methanone ( 4j) displayed highest larvae mortality at a 4 μg/ml dose in 24 h. Compounds (3-(4-methoxyphenyl)-2,3-dihydropyrazolo[4,3-b]indol-1(4H)-yl)(pyridin-4-yl)methanone ( 4h ) and (3-(3-hydroxy-4-methoxyphenyl)-2,3-dihydropyrazolo[4,3-b]indol-1(4H)-yl)(pyridin-4-yl)methanone ( 4i ) showed a significant knockdown activity after 24 h with 70% mortality. Furthermore, (3-(4-chlorophenyl)-2,3-dihydropyrazolo[4,3-b]indol-1(4H)-yl)(pyridin-4-yl)methanone ( 4c ) and (3-(3-bromo-5-hydroxy-4-methoxyphenyl)-2,3-dihydropyrazolo[4,3-b]indol-1(4H)-yl)(pyridin-4-yl)methanone ( 4j ) displayed promising lipoxygenase inhibitory activity with a mortality of 70% and 60%, respectively.     

Synthesis and antioxidant activity of some thiazolidin-4-one derivatives

Abstract  4-Fluorobenzaldehyde was used for the preparation of 2-(4-fluorophenyl)thiazolidin-4-one derivatives which were allowed to react with chloroacetonitrile and acrylonitrile to produce 3-(2-(4-fluorophenyl)-4-oxothiazolidine3-yl)acetonitrile and 3-(2-(4-fluorophenyl)-4-oxothiazoledine-3-yl)propanenitrile. Biological evaluation of some of the compounds showed that many had promising antioxidant activity. Graphical Abstract        

Oxidation of 2-(thiazol-2-yl)acrylonitrile derivatives with an H<Subscript>2</Subscript>O<Subscript>2</Subscript>—KOH system: Convenient route to new oxirane-2-carboxamides

An efficient procedure was developed for the synthesis of previously unknown 3-aryl(styryl)-2-(4-arylthiazol-2-yl)oxirane-2-carboxamides and 2-(4-arylthiazol-2-yl)-1-oxaspiro[2.5]octane-2-carboxamides based on treatment of (E)-3-aryl-2-(4-arylthiazol-2-yl)acrylonitriles and cyclohexylidene(4-arylthiazol-2-yl)acetonitriles with an H₂O₂—KOH system in EtOH. Oxidation of (E)-3-(4-chlorophenyl)-2-(4-phenylthiazol-2-yl)acrylonitrile with an H₂O₂—AcOH system affords 3-(4-chlorophenyl)-2-(4-phenylthiazol-2-yl)oxirane-2-carbonitrile in 55% yield. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2319–2322, October, 2005.     

Synthesis and characterization of novel 2-(1-benzyl-3-[4-fluorophenyl]-1H-pyrazol-4-yl)-7-fluoro-4H-chromen-4-one derivatives

Novel 1-benzyl-3-(4-fluorophenyl)-1H-pyrazole-4-carbaldehydes 3a to 3e were synthesized via Vilsmeier-Haack reaction of the appropriate 1-benzyl-2-(1-(4-fluorophenyl)ethylidene)hydrazines, derived from 4-fluoroacetophenone 1 with substituted 2-benzylhydrazines 2a to 2e . The base catalyzed condensation of 1-benzyl-3-(4-fluorophenyl)-1H-pyrazole-4-carbaldehydes 3a to 3e with 1-(4-fluoro-2-hydroxyphenyl)ethanone 4 gave (E)-3-(1-benzyl-3-(4-fluorophenyl)-1H-pyrazol-4-yl)-1-(4-fluoro-2-hydroxyphenyl)prop-2-en-1-ones 5a to 5e . On cyclization with dimethyl sulfoxide (DMSO)/I₂, compounds 5a to 5e gave 2-(1-benzyl-3-(4-fluorophenyl)-1H-pyrazol-4-yl)-7-fluoro-4H-chromen-4-ones 6a to 6e . Structures of all novel compounds were confirmed by infrared (IR), proton nuclear magnetic resonance (¹H NMR), carbon nuclear magnetic resonance (¹³C NMR), and mass spectral data. All the synthesized compounds were screened for their antibacterial activities.     

间氯苯基锰卟啉-5-氟尿嘧啶配合物的合成及其对癌细胞的抑制活性

合成了4种新5-氟尿嘧啶-卟啉衍生物：5-[3-(2-(5-氟尿嘧啶-1-基)乙氧基)苯基]-10,15,20-三(3-氯苯基)卟啉(1a)、5-[3-(2-(5-氟尿嘧啶-1-基)乙氧基)苯基]- 10,15,20-三(3-氯苯基)锰卟啉(2a)、5-[3-(3-(5-氟尿嘧啶-1-基)丙氧基)苯基]-10,15,20-三(3-氯苯基)锰卟啉(2b)和5-[3-(4-(5-氟尿嘧啶-1-基)丁氧基)苯基]-10,15,20-三(3-氯苯基)锰卟啉(2c),通过UV-Vis、IR、MS及元素分析表征了它们的结构。 用噻唑蓝法（MTT法）测定了化合物2a、2b和2c对人胃癌细胞株BGC-823的抑制活性。 化合物2b的半数抑制浓度IC50为1.34 μmol/L,表明有一定的细胞毒作用。     

Highly luminescent tridentate N^C*N platinum(II) complexes featured in fused five-six-membered metallacycle and diminishing concentration quenching

A series of cyclometalating ligands, N-phenyl-N-(3-(pyridin-2-yl)phenyl)pyridin-2-amine (L1), N-(3-(1H-pyrazol-1-yl)phenyl)-N-phenylpyridin-2-amine (L2), N-phenyl-N-(3-(quinolin-2-yl)phenyl)pyridin-2-amine (L3), N-phenyl-N-(3-(pyridin-2-yl)phenyl)quinolin-2-amine (L4), N-(3-(isoquinolin-1-yl)phenyl)-N-phenylpyridin-2-amine (L5), and N-phenyl-N-(3-(pyridin-2-yl)phenyl)isoquinolin-1-amine (L6), were synthesized, which reacted with K(2)PtCl(4) in glacial acetic acid to produce N^C*N-coordinated platinum(II) complexes featured in a fused five-six-membered metallacycle, 1-6, respectively. The structures of 1, 3, 4, and 6 were determined by single crystal X-ray crystallography. The square geometries of the complexes are improved when compared with those of the N^C^N-coordinated complexes as the bite angles for the platinum in N^C*N-coordinated complexes 1, 3, and 4 are increased. The Pt-C bonds (1.94-1.95 ?) are shorter than those of C^N^N-coordinated platinum complexes but longer than those found for N^C^N-coordinated platinum complexes. With the increase of the steric interaction, the distortion of the molecules from a planar coordination geometry becomes more and more severe from 1 to 3 to 4 and 6, and in 6, the N-phenyl ring has to stand up on the coordination sphere to minimize the steric interaction with the N-isoquinolyl ring. The photophysical properties of the complexes were studied, and their absorption and emission spectra were interpreted by relating to the structural features revealed by the X-ray crystal structures and the orbital characters predicted by DFT calculations. All complexes are emissive in fluid at room temperature, and the quantum yields (up to 0.65) are comparable to those of highly emissive N^C^N-coordinated platinum complexes. Self-quenching was not observed in the concentration range of 10(-6) to 10(-4) M. Large rigidochromic shifts for the emissions of 2, 4, and 6 upon cooling from room temperature to rigid glass (77 K) were observed. Two different triplet states that control the emissions were proposed to account for the photophysical properties of 6.     

Chemotherapeutic agents. IX. Synthesis and pesticidal activities of bis[4-aryl/alkyl-1, 2, 4-triazoline-5-thione-3-yl]alkanes and 1 -Aryl/alkyl-3-[4-(4-aryl/alkyl-1, 2, 4-triazoline-5-thione-3-yl)phenyl]thiourea and related compounds

Various bis[4-aryl/alkyl-1, 2, 4-triazoline-5-thione-3-yl]alkanes ( 3 ) were prepared from base cyclization of bis thiosemicarbazide 2 and transformed into sulphides by reaction with different alkyl halides in alkaline medium. These compounds were further oxidised to sulphones 5 with acidic potassium permanganate. 1-Aryl-3-[4-(4-aryl/alkyl-1, 2, 4-triazoline-3-thione-5-yl)phenyl]thioureas ( 8 ) were prepared in two steps from p-aminophenylhydrazide ( 6 ) and aryl/alkylisothiocyanates. Alkylation of 8 with different alkyl halides yielded exclusively sulphides 9 . Some sulphides 12 and Mannich bases 13 from 5-(p-fluorophenyl)-1, 3, 4-oxadiazol-2-thione ( 11 ) were also prepared to evaluate their pesticidal activities. All the prepared compounds were screened for pesticidal activities but none of them exhibited any significant activity.     

New process for the synthesis of imidazo[4,5-b]pyridine derivatives as potent orally active thromboxane a2 receptor antagonists

A new synthetic route to prepare the 4-[3-(4-chlorophenyl)methyl-6-chloroimidazo[4,5-b]pyridin-2-yl]-3,3-dimethylbutanoic acid (UP 116-77) is described. UP 116-77 is a potent orally active TXA₂/PGH₂ receptor antagonist currently under pharmacological investigation. Its development needed a suitable synthesis for industrial processing. The cyclization of 3-amino-5-chloro-2-(4-chlorophenyl)methylaminopyridine 4 with 3,3-dimethylglutaric anhydride in refluxing acetic acid affords a new efficient and simple way to UP 116-77 and subsequently to various 2-substituted imidazo[4,5-b]pyridine derivatives.     

Novel oxazole-based emitters for high efficiency fluorescent OLEDs: Synthesis,characterization, and optoelectronic properties

Two novel oxazole derivatives 4-(6-(4,5-diphenyloxazol-2-yl)pyridin-3-yl)-N,N-diphenylaniline (TPA-PPO) and 2-(5-(4-(9H-carbazol-9-yl)phenyl)pyridin-2-yl)-4,5-diphenyloxazole (CzPh-PPO) have been designed and synthesized. The photophysical, electrochemical and thermal characters of the compounds were systematically investigated, which consistent well with the theoretical DFT calculations. TPA-PPO and CzPh-PPO exhibit high photoluminescent quantum yield of 0.63 and 0.59, respectively. The device using TPA-PPO as the dopant showed deep blue emission with a high EQE of 1.77%. A white OLED was obtained using the single emitter of CzPh-PPO with an EQE of 1.24%.     

N-hetaryl-2-cyanoacetamides in the synthesis of substituted (E)-N-hetaryl-2-cyanoacrylamides, (E)-N-alkyl-N-hetaryl-2-cyanoacrylamides, and 6-amino-2-oxo-4-phenyl-1-(pyridin-2-yl)-1,2-dihydropyridine-3,5-dicarbonitriles

Knoevenagel condensation of N-hetaryl-substituted cyanoacetamides with aldehydes gave the corresponding (E)-N-hetaryl-2-cyanoacrylamides which were converted into (E)-N-alkyl-N-hetaryl-2-cyanoacrylamides and 6-amino-2-oxo-4-phenyl-1-(pyridin-2-yl)-1,2-dihydropyridine-3,5-dicarbonitriles. The structure of (E)-N-(pyridin-2-yl)-2-cyano-3-phenylprop-2-enamide was determined by X-ray analysis. Original Russian Text ? I.V. Dyachenko, V.D. Dyachenko, E.B. Rusanov, 2007, published in Zhurnal Organicheskoi Khimii, 2007, Vol. 43, No. 1, pp. 81–86.     

New viologen analogs: 1,4-bis[2-(pyridin-4-yl)ethenyl]benzene quaternary salts

Alkylation of 1,4-bis[2-(pyridin-4-yl)ethenyl]benzene with alkyl p-toluenesulfonates and dimethyl sulfate gave new viologen analogs, 1-alkyl-4-(2-{4-[2-(1-alkylpyridinium-4-yl)ethenyl]phenyl}ethenyl)-pyridinium bis(p-toluenesulfonates) and sulfate. Their derivatives with tetrafluoroborate and tetraphenylborate ions were also obtained. Spectral properties of the synthesized compounds were examined, and their structure was determined by X-ray analysis.     

Analgesic and antimicrobial studies of some 2,4-dichloro-5-fluorophenyl containing arylidenetriazolothiadiazines

2,4-Dichloro-5-fluorophenyl containing 7-arylidenetriazolothiadiazines were obtained by the reaction of 4-amino-3-(2,4-dichloro-5-fluorophenyl)-5-mercapto-1,2,4-triazole with 2,3-dibromo-1,3-diarylpropan-1-ones, and also by the reaction of 4-amino-3-(2,4-dichloro-5-fluorophenyl)-5-mercapto-1,2,4-triazole with α-bromopropenones in the presence of a base. The structure of the 7-arylidenetriazolothiadiazines was confirmed by an alternative synthesis. A plausible mechanism for the formation of 7-arylidenetriazolothiadiazines is proposed. All newly synthesized compounds were screened for their analgesic and antimicrobial activities. Compounds bearing 4-chlorophenyl or 3,4-methylenedioxyphenyl moieties at position 7 of the arylidenetriazolothiadiazines showed excellent analgesic activity. Arylidenetriazolothiadiazines carrying a phenyl, 4-chlorophenyl, 4-methylphenyl, 3,4-dimethoxyphenyl, and 2,4-dichlorophenyl moieties at position 7 showed excellent antibacterial and antifungal activities. Correspondence: Mari Sithambaram Karthikeyan, Department of Chemistry, Mangalore University, Mangalagangothri 574199, Karnataka, India.     

Synthesis,characterization, and immobilization of nickel(II) tetradentate Schiff-base complexes on clay as heterogeneous catalysts for the oxidation of cyclooctene

Nickel(II) tetradentate Schiff-base complexes of N,N′-(bis(pyridin-2-yl)formylidene)ethane-1,2-diamine (L1), N,N′-(bis(pyridin-2-yl)formylidene)cyclohexane-1,2-diamine (L2), N,N′-(bis(pyridin-2-yl)formylidene)benzene-1,2-diamine (L3), N,N′-(bis(pyridin-2-yl)formylidene)meso-stilben-1,2-diamine (L4), and N,N′-(bis(pyridin-2-yl)formylidene)propane-1,3-diamine (L5) were synthesized, characterized, and immobilized on sodium montmorillonite. The complexes were characterized by IR spectroscopy, diffuse reflectance spectra (DRS), and atomic absorption spectroscopy (AAS). IR and DRS data of the heterogeneous catalysts show that the Ni(II) complexes were physically entrapped within the sodium montmorillonite clay. The supported complexes show good catalytic activity for the epoxidation of cyclooctene using tert-butylhydroperoxide (TBHP) as oxygen source in acetonitrile. The Ni-catalyzed oxidation proceeds with 62.3% selectivity for epoxidation with 69% conversion for supported [Ni(L5)].