Ferrocenyl pyrazolines: Preparation, structure, redox properties and DFT study on regioselective ring-closure

Cyclocondensation of 1-phenyl-3-ferrocenyl-2-propen-1-one (1) with RNHNH2 hydrazines and the substituent-dependent product distribution were investigated. With methylhydrazine, formation of two regioisomeric pairs of pyrazolines and pyrazoles was observed. The ratio of the products varied with the solvent and temperature. Transformation of 5-ferrocenyl-N-substituted pyrazolines into pyrazoles was systematically studied and DDQ was found to be the most suitable reagent. Mechanism of the cyclization reactions taking place under kinetic- and thermodynamic controls was supported with DFT calculations. The energy-dependence of the transformation of pyrazoline to pyrazole was investigated also by EI MS. Structure determination of the new compounds was performed by IR, MS and NMR methods including 2D-HMQC, 2D-HMBC, DEPT and DIFFNOE measurements. For two compounds structures were also proved by X-ray diffraction.     

1-苯基-3-(3'-吲哚基)-5-取代苯基-2-吡唑啉的合成及1H NMR和MS中的取代基效应

J-(3'-吲哚基)-3-取代苯基-2-丙烯-1-酮与茉肼反应,合成了10种新的1-苯基-3-(3'-吲哚基)-5-取代苯基-2-吡唑啉衍生物,其结构通过各种波谱证实.讨论了此系列化合物¹HNMR和Ms中的取代基效应,得出取代基常数σ或σ⁺与质子化学位移,碎片相对丰度之间存在着良好的线性关系.     

4-Functionally Substituted 3-Heterylpyrazoles: IV. 1-Phenyl-3-aryl(heteryl)-5-(4-pyrazolyl)-2-pyrazolines

3-Aryl(heteryl)-4-formylpyrazoles in condensation with methyl aryl(heteryl) ketones afforded 1-aryl(heteryl)-3-[3-aryl(heteryl)-4-pyrazolyl]propenones. The latter reacted with phenylhydrazine yielding 1-phenyl-3-aryl(heteryl)-5-(4-pyrazolyl)-2-pyrazolines.     

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.     

A new and efficient approach to pyrazolines. First synthesis of 3-aryl-5-dichloromethyl-2-pyrazolines

An efficient synthetic method for dichloromethylated pyrazolines has been established. 1-Aryl-4,4-dichlorobut-3-en-1-ones 4 were efficiently prepared by treatment of acetophenones with anhydrous chloral, followed by dehydration and reductive dechlorination. Compounds 4 reacted with hydrazine hydrate and methylhydrazine to give the respective 5-dichloromethyl-2-pyrazolines in high to quantitative yields. The molecular structure of 5-dichoromethyl-1-methyl-3-(2-naphthyl)-2-pyrazoline has been determined by X-ray crystallography.     

New derivatives of 3-aminoindole. Synthesis of 2-aryl(hetaryl)-3-(3,5-dimethyl-1-pyrazolyl)indoles

The interaction of arylhydrazines with ù-(3,5-dimethyl-1-pyrazolyl)acetophenones and acetyl(2-thiophene) leads to arylhydrazones, which are converted by Fischer cyclization into 2-aryl(thienyl)-3-(3,3-dimethyl-1-pyrazolyl)indoles with substituents in positions 1, 5, and 7.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1662–1669, November, 2004.     

Regioselectivity in the reaction of paraformaldehyde with (1S,2S)-2-aryl(hetaryl)methylamino-1-(4-nitrophenyl)-1,3-propanediols

The reaction of paraformaldehyde with (1S,2S)-2-aryl(hetaryl)methylamino-1-(4-nitrophenyl)-1,3-propanediols produces a mixture of isomeric 3-aryl(hetaryl)methyl-4-hydroxymethyl-5-(4-nitrophenyl)- and 3-aryl(hetary)methyl-4-hydroxy(4-nitrophenyl)methyloxazolidines and is reversible. Université d'Auvergne, Faculté de Farmacie, 28, Place Henri Dunant, Clermont-Ferrand, France. Samara State University, Samara 443011, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 536–541, April, 1999.     

Synthesis and structure of cobalt(II) 1-aryl-3-aryl(alkyl)-5-(benzothiazol-2-yl)formazanates

New mono- and binuclear cobalt(II) complexes based on 1-aryl-3-aryl(alkyl)-5-(benzothiazol-2-yl)formazans were synthesized. The structure of the synthesized compounds was determined by electronic and IR absorption spectroscopy, mass spectrometry, and X-ray crystallography.     

Chemistry of iminofurans: IX. Synthesis and cyclization of (2<Emphasis Type="Italic">Z</Emphasis>)-2-{(2<Emphasis Type="Italic">Z</Emphasis>)-2-[2-(3-R-adamantan-1-yl)-2-oxoethylidene]hydrazinyl}-4-(het)aryl-4-oxobut-2-enoic acids

1-(3-R-adamantan-1-yl)-2-[(triphenyl-λ⁵-phosphanylidene)hydrazinylidene]ethanone reacted with 4-aryl(hetaryl)-2,4-dioxobutanoic acids to give 2-{2-[2-(3-R-adamantan-1-yl)-2-oxoethylidene]hydrazinyl}-4-aryl(hetaryl)-4-oxobut-2-enoic acids which were shown to exist in solution as mixtures of Z- and E-isomeric enehydrazine tautomers. The products underwent cyclization to 3-{[2-(3-R-adamantan-1-yl)-2-oxoethylidene]- hydrazinylidene}-5-aryl(hetaryl)furan-2(3H)-ones.     

Synthesis of some isomeric 4-ethoxycarbonyl-3-and 5-(1- and 2-hydroxyalkyl)-1,3- and 1,5-dimethylpyrazoles from 3-(2H)furanones and 2,3-dihydro-4-pyrones

The title compounds were prepared by reaction of 3-(2H)furanones and 2,3-dihydro-4-pyrones with methylhydrazine or alternatively by methylation of the corresponding N-unsubstituted pyrazoles. ¹³C and ¹H nmr were used to assign the isomeric 3-methyl or 5-methyl structures.     

Synthesis and spectral characteristics of Ni(II) 1-aryl-3-aryl(alkyl)-5-(benzothiazole-2-yl)formazanates

Novel mono-and binuclear metal complexes of Ni(II) based on 1-aryl-3-aryl(alkyl)-5-(benzothiazole-2-yl)formazanes were synthesized and their structures were studied by the electronic and IR spectroscopy, mass spectrometry and megnetochemical methods.     

Cyclic transformations of 5-aryl(or benzyl)-3-(2-bromoethyl- 1,3,4-oxadiazol-2(3H)-ones into 1-aminoimidazolidin-2-one and 5,6-dihydro-4H-1,3,4-oxadiazine derivatives

5-Aryl(or benzyl)-3-(2-bromoethyl)-1,3,4-oxadiazol-2(3H)-ones 3 have been prepared. They were reacted with secondary alkylamines without any change of the heterocycle to give amino derivatives 6 , but with primary alkylamines, cyclic transformation occurred to give 1-acylamino-3-alkylimidazolidin-2-ones 7 . In the presence of sodium alcoholate, bromo compounds 3 were transformed into 2-aryl(or benzyl)-4-alkoxycarbonyl-5,6-dihydro-4H-1,3,4-oxadiazines 9 .     

Synthesis,Crystal Structure and Theoretical Calculations of N-Benzyl-1-(5-(3-chlorophenyl)-1,3,4-oxadiazol-2-yl)cyclopentanamine

N-benzyl-1-(5-(3-chlorophenyl)-1,3,4-oxadiazol-2-yl)cyclopentanamine was synthesized via one-pot reaction of appropriate benzylamine, cyclopentanone,(N-isocyanimino)triphenylphosphorane and m-chlorobenzoic acid. The quantum theoretical calculations for crystal structure were performed by density functional theory(DFT/B3LYP/6-311+G*). From the optimized structure, geometric parameters were obtained and experimental measurements were compared with the calculated data. Frontier molecular orbitals(FMOs), total density of states(DOS), molecular electrostatic potential(MEP), molecular properties, natural charges, NMR parameters and NBO analysis for the product were investigated by theoretical calculations.     

Synthesis and photochromic and fluorescence properties of 3-(1-benzyl-5-methoxy-2-methylindolyl)-4-thienyl-substituted furan(pyrrole)-2,5-diones

New nonsymmetrical dihetarylethenes, 3-(1-benzyl-5-methoxy-2-methyl-1H-indol-3-yl)-4-(3-thienyl)furan-2,5-dione and 1-alkyl- and (1-aryl)-3-(1-benzyl-5-methoxy-2-methyl-1H-indol-3-yl)-4-(3-thienyl)-1H-pyrrole-2,5-dione, exhibiting photochromic properties in solutions were synthesized. Noncyclic isomers of dihetarylethenes show fluorescence with quantum yields up to 0.13.     

Synthesis and Structure of (2E)-3-Aryl(hetaryl)-2-[5-bromo-4-aryl(hetaryl)-1,3-thiazol-2-yl]acrylonitriles

Russian Journal of General Chemistry - Bromination of (2E)-3-aryl(hetaryl)-2-[4-aryl(hetaryl)-1,3-thiazol-2-yl]acrylonitriles proceeds regioselectively at the C5 atom of the thiazole ring with the...     

An X-ray and DFT Computational Study on 1-（Naphthalene-2-yl）-2-（1H-pyrazol-1-yl） ethanone O-butyl Oxime

The title compound, 1-(naphthalene-2-yl)-2-(1H-pyrazol-1-yl)ethanone O-butyl oxime, I, was synthesized. The crystal and molecular structures of I were determined by IR, 1H-NMR, mass spectrum, elemental analysis and X-ray single crystal diffraction. Molecular geometry from X-ray experiment of I in the ground state was compared using the Density Functional Theory (DFT) with B3LYP/6-311G(d,p) basis set. In addition, DFT calculation, molecular electrostatic potentials (MEP) and frontier molecular orbitals of I were performed at the B3LYP/6-311G(d,p) level of the theory.     

钯催化下(Z)-3-碘-3-三氟甲基-1-芳基烯丙醇与末端炔 烃的偶联反应

在Pd(PPh~3)~4/CuI催化下和使用1mol的NEt~3作碱和THF作溶剂,(Z)-3-碘-3-三氟甲基-1-芳基烯丙醇(1)与末端炔烃(3)反应得到正常的偶联产物5。当以NEt~3作碱和溶剂,Pd(PPh~3)~4/CuI催化1与3的交叉偶联反应生成化合物4。4为正常偶联化合物5在NEt~3存在下双键发生重排反应的产物。     

One-pot multi-component synthesis of novel ethyl-2-(3-((2-(4-(4-aryl)thiazol-2-yl)hydrazono)methyl)-4-hydroxy/isobutoxyphenyl)-4-methylthiazole-5-carboxylate derivatives and evaluation of their in vitro antimicrobial activity

A novel series of ethyl-2-(3-((2-(4-(4-aryl)thiazol-2-yl)hydrazono)methyl)-4-hydroxy/isobutoxyphenyl)-4-methylthiazole-5-carboxylate derivatives ( 4a-f and 5a-f ) were synthesized by employing one-pot multi-component approach involving ethyl 2-(3-formyl-4-oxy/isobutoxyphenyl)-4-methylthiazole-5-carboxylate, thiosemicarbazide and various phenacyl bromides/3-(2-bromoacetyl)-2H-chromen-2-one/2-(2-bromoacetyl)-3H-benzo[f]chromen-3-onein ethanol in the presence of catalytic amount of acetic acid. The structures of all the synthesized compounds were confirmed with spectral analysis, ie, IR, 1H NMR, 13C NMR and mass spectrometry, and all the compounds were screened for their in vitro antimicrobial activity.     

（E）-1-[4-（2-hydroxy-5-methoxybenzylideneamino）-phenyl]ethanone and （E）-1-[4-（2-hydroxy-4-methoxybenzylideneamino） phenyl]ethanone：X-ray and DFT-calculated structures

The isomeric structures of(E)-1-[4-(2-hydroxy-5-methoxybenzylideneamino)-phenyl] ethanone(I) and(E)-1-[4-(2-hydroxy-4-methoxybenzylideneamino) phenyl]ethanone(Ⅱ) ,both C16H15NO3,have been determined using X-ray diffraction techniques and characterized by IR,and their molecular structures have also been optimized at the B3LYP/6-31G(d,p) level using density functional theory(DFT) . The energetic behaviors of the title compounds in solvent media have been examined using B3LYP method with the 6-31G(d,p) basis set by applying the polarizable continuum model(PCM) . The total energies of the title compounds decrease with the increasing polarity of the solvent. In addition,DFT calculations of the title compounds' molecular electrostatic potentials(MEP) were performed at the B3LYP/6-31G(d,p) level of theory. X-ray study shows that the title compounds both have strong intramolecular O-H…N hydrogen bonds. The molecules of Ⅰ are linked into a one-dimensional framework structure by C-H…π interactions,while in Ⅱ,intermolecular π···π interactions result in the formation of infinite chains running along the [010].     

Synthesis and tautomerism of 2-[3(5)-aryl(methyl)pyrazol-4-yl]-1-benzimidazoles

An efficient method has been developed for the synthesis of 2-[3(5)-aryl(methyl)pyrazol-4-yl]-1H-benzimidazoles by cyclocondensation of 2-acylmethyl-1H-benzimidazoles benzoylhydrazones with DMF dimethylacetal. The tautomerism of the compounds obtained via migrations of a proton between the pyrazole nitrogen atoms has been studied by ¹H NMR. The more stable tautomers have electron acceptor aryl substituents placed at position 3 of the pyrazole ring and electron donor aryl substituents or a methyl at position 5. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1370–1377, September, 2006.