bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and spectroscopic properties of 4‐(4‐carboxyphenyl)‐3,3′,5′‐trimethyl‐2,2′‐pyrromethen‐1,1′‐BF2 complex and its methyl ester
Authors: Cheng Lingjiang , Lightner David A. 
Published: March 2009

AbstractA new, strongly absorbing red dipyrrole chromophore 1 suitable for exciton coupling studies has been synthesized and shown to exhibit an intense absorption (ϵ˜ 57,000) at λ (max) ˜520 nm and a strong fluorescence at λ (em) ˜555 nm.
A study of the friedel‐crafts acylation of 1‐benzenesulfonyl‐1H‐pyrrole in the preparation of 3‐aroylpyrroles
Authors: Nicolaou Ioannis , Demopoulos Vassilis J. 
Published: March 2009

AbstractIn this work, we studied the aluminum chloride catalyzed reaction of 1‐benzenesulfonyl‐1H‐pyrrole with a series of eleven aroyl chlorides. The products formed were not isolated, but hydrolyzed to the target 3‐aroylpyrroles in overall yields, usually, higher than 50%. However, in the cases with the π electron rich 1‐phenyl‐1H‐pyrrole‐3‐carbonyl chloride and 1‐methyl‐1H‐indole‐3‐carbonyl chloride significant C‐2 substitution occured, resulting in the isolation of the corresponding 1‐benzenesulfonyl‐2‐aroylpyrroles as the predominant or the sole products. The desired C‐3 isomers were synthesized starting with 1‐triisopropylsilanyl‐1H‐pyrrole.
Reductive metallation of 6‐methyl‐2,3‐diphenylquinoxaline. Synthesis of 1,4‐dihydro‐1,4‐diazine derivatives
Authors: Öcal Nüket , Turgut Zuhal , Kaban Şniz 
Published: March 2009

AbstractThe reductive metallation of 6‐methyl‐2,3‐diphenylquinoxaline 1 with sodium metal in tetrahydrofuran and inert atmosphere to a monomeric dianion 2 has been explored and the nucleophilicity of this disodium adduct was investigated with various alkylation and acylation reagents. An annulation of the pyrazine ring system was accomplished by treating the dianion with polymethylene chlorides, Cl(CH2)nCl, n = 3,4.
The preparation of 4‐oxo‐N‐aryl‐4H‐1‐benzopyran‐2‐acetamides by the condensation/cyclization of trilithiated acetoacetanilides with lithiated methyl salicylates
Authors: Hurst Douglas R. , French Kristen L. , Angel April J. , Williams Angela R. , Rampey Mary E. , Guion Tina S. , Chan Kam W. , Kassis Camille M. , Martinez Shannon L. Studer , Beam Charles F. 
Published: March 2009

AbstractSeveral acetoacetanilides were trilithiated in excess lithium diisopropylamide, and the resulting polylithiated intermediates were regioselectively condensed with lithiated methyl salicylates followed by acid cyclization to substituted 4‐oxo‐N‐aryl‐4H‐1‐benzopyran‐2‐acetamides (benzopyranone‐2‐acetamides).
Synthesis of indolizidinediones annelated to a furan ring
Authors: Szemes Fridrich , Marchalín ŠTefan , Bar Nathalie , Decroix Bernard 
Published: March 2009

AbstractThe furo[2,3(or 3,2)‐f]indolizidinediones 4a,b were synthesized in five steps from glutamic acid in good yield. The ketones were converted into trans alcohols 5a,b or oximes 6a,b (either as syn‐anti mixture or as single isomer). The selectivity of these reactions is discussed.
A convenient synthesis of (z)‐3‐(α‐alkoxycarbonyl‐α‐cyanomethylene)‐2‐oxo‐1,2,3,4‐tetrahydroquinoxalines and related compounds
Authors: Yamada Yoichi , Yasuda Heinosuke 
Published: March 2009

Abstract(Z)‐3‐(α‐Alkoxycarbonyl‐α‐cyanomethylene)‐2‐oxo‐1,2,3,4‐tetrahydroquinoxalines 3 and (Z)‐3‐(α‐alkoxycarbonyl‐α‐cyanomethylene)‐3,4‐dihydrobenzo[g]quinoxalin‐2(1H)‐ones 5 possessing various alkoxycarbonyl groups were prepared in good yields directly from the reaction of dialkyl (E)‐2,3‐dicyanobutendioates 1 with o‐phenylenediamine (2) or with 2,3‐diaminonaphthalene (4), respectively. Furthermore, 2,3‐diaminopyridine (6) and 3,4‐diaminopyridine (7) were reacted with the diethyl ester 1b to give (Z)‐2‐(α‐cyano‐α‐ethoxycarbonylmethylene)‐1,2‐dihydro‐4H‐pyrido[2,3‐b]pyrazin‐3‐one (8) and (Z)‐3‐(α‐cyano‐α‐ethoxycarbonylmethylene)‐3,4‐dihydro‐1H‐pyrido[3,4‐b]pyrazin‐2‐one (9), respectively. The structural studies of 3, 5, 8, and 9 were carried out by nmr experiments in some details.
Unusual behavior of pyrazolo[1,2‐a]pyrazoles in fast atom bombardment (fab) and frit‐fast atom bombardment (Frit‐FAB) mass spectrometry. Influence of the matrix
Authors: Enjalbal Christine , Aubagnac Jean‐Louis , Trofimenko Swiatoslaw , Claramunt Rosa , Sanz Dionisia , Elguero José 
Published: March 2009

AbstractThe nature of the matrix used in Fast Atom Bombardment (FAB) mass spectrometry analyses of pyrazolo[1,2‐a]pyrazoles was found to influence significantly their positive and negative ions mass spectra. Indeed the use of glycerol provided an abundant ion corresponding to the protonated molecule (M+H)+ whereas the meta‐nitrobenzyl alcohol favored the formation of the radical ion M+°. Such results which are in accordance with the oxidoreduction properties of the matrices studied were also established in Frit‐FAB mass spectrometry analyses of pyrazolo[1,2‐a]pyrazoles.
Synthesis and reduction of thieno[2′,3′(3′,2′ or 3′,4′):5,6]‐azocino[2,1‐a]isoindole‐7, 13‐diones
Authors: Othman Mohamed , Pigeon Pascal , Decroix Bernard 
Published: March 2009

AbstractA synthesis of the thieno[2′,3′(3′,2′ or 3′,4′):5,6]azocino[2,1‐a]isoindole‐7,13‐diones 6a‐c was developed from N‐thienylethylphthalimides 3a‐c using a Wittig reaction followed by a Friedel‐Crafts cyclization of acetic acid derivatives 5a‐c. Reduction of ketones 6a‐c into alcohols 7a‐c was stereo specific.
The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 20. Benzo[h]thieno[3′,2′:4,5]thieno[2,3‐c]‐quinoline, benzo[f]thieno[3′,2′:4,5]thieno[2,3‐c]quinoline, benzo[f]thieno[3′,2′:4,5]thieno[2,3‐c]tetrazolo[1,5‐a]quinoline and benzo[f]thieno[3′,2′:4,5]thieno[2,3‐c][1,2,4]triazolo[4,3‐a]quinoline
Authors: Luo Jiann‐Kuan , Federspiel Ronald F. , Castle Raymond N. 
Published: March 2009

AbstractFour previously unknown polycyclic heterocyclic ring systems, namely, benzo[h]thieno[3′,2′:4,5]‐thieno[2,3‐c]quinoline (6), benzo[h]thieno[3′,2′:4,5]thieno[2,3‐c]quinoline (11), benzo[f]thieno‐[3′,2′:4,5]thieno[2,3‐c]tetrazolo[1,5‐a]quinoline (12) and benzo[f]thieno[3′,2′:4,5]thieno[2,3‐c][1,2,4]‐triazolo[4,3‐a]quinoline (13), were synthesized via oxidative photocyclization. Unequivocal total assignments of the proton and carbon nmr spectra of 6 and 11 were made through the concerted usage of COSY, HMQC and HMBC two‐dimensional nmr spectroscopic methods.
Total synthesis of 5‐demethylellipticine
Authors: Ergün Yavuz , Patir Süleyman , Okay Gürol 
Published: March 2009

AbstractEthyl 1,2‐dihydro‐4‐methylcarbazole‐3‐carboxylate and 11‐methl‐6H‐pyrido[4,3‐b] carbazole (5‐demethylellipticine) have been synthesized by different routes.
α,ω‐Bis(4‐substituted‐3‐quinolinylthio)alkanes from reactions of thioquinanthrene with alkoxides
Authors: Boryczka Stanislaw 
Published: March 2009

AbstractThe reaction of thioquinanthrene 1 with sodium alkoxides and α,ω‐dihaloalkanes leads to the formation of α,ω‐bis[4‐(4‐methoxy‐3‐quinolinylthio)‐3‐quinolinylthio]alkanes 4. The yield depends on the nature of α,ω‐dihalo‐alkanes. The effect of α,ω‐dihaloalkanes of the following types: XCH2X (X = Cl,Br,I), X(CH2)2X (X = Cl,Br,I), Br(CH2)3Br and Br(CH2)6Br were studied. The preparation of 4‐alkoxy‐3′‐(ω‐bromoalkylthio)‐3,4′‐diquinolinyl sulfide 3 and their transformation to α,ω‐bis(4‐alkoxy‐3‐quinolinylthio)alkanes 6 were studied as well.
Synthesis of novel pyrindine derivatives from a facile reaction of 2,5‐bisarylidenecyclopentanone and malononitrile
Authors: Al‐Arab Mohammad M. , Al‐Saleh Fowzia S. , Mayoof Sadeq M. 
Published: March 2009

AbstractStarting from 2,5‐bisarylidenecyclopentanone and malononitrile (1:1) several novel pyrindine derivatives were synthesized by a facile and convenient one‐pot reaction using sodium ethoxide in absolute ethanol at room temperature. The structure of the reaction products was unambiguously deduced ftom their infrared, 1H‐nuclear magnetic resonance spectroscopy, elemental analysis and single crystal X‐ray crystallography.
Urea as leaving group in the synthesis of 3‐(tert‐butyl)perhydro‐1,5,3‐dithiazepine
Authors: Wellmar Ulf 
Published: March 2009

AbstractThe new compound 3‐(tert‐butyl)perhydro‐1,5,3‐dithiazepine has been synthesised from 5‐(tert‐butyl)perhydro‐1,3,5‐triazin‐2‐one in 45% yield. In the reaction, urea acts as the leaving group being exchanged for the S‐CH2‐CH2‐S fragment of the product.
Selenium heterocycles. XLIII. Syntheses of 3,5‐Diaryl‐1,2,4‐thiadiazoles and 3,5‐Diaryl‐1,2,4‐selenadiazoles
Authors: Shafiee A. , Ebrahimzadeh M. A. , Maleki A. 
Published: March 2009

AbstractStarting from readily available α‐arylsulfonyl‐α‐bromoacetophenones 2 a series of 3,5‐diaryl‐1,2,4‐thiadiazoles and 3,5‐diaryl‐1,2,4‐selenadiazoles were prepared in moderate yield. Reaction of compounds 2 with thiourea or selenourea gave 2‐amino‐5‐arylsulfonyl‐4‐phenylthiazole or selenazole in good yield.
Synthesis of 2′‐[2‐(5‐benzyloxyindolyl)]propylamine derivatives
Authors: Marco José L. , Martin Gema 
Published: March 2009

AbstractThe synthesis of some 2′‐[2‐(5‐benzyloxyindolyl)]propylamine derivatives 1–15 from 2‐(5‐benzyloxyindole)carboxyaldehyde (16) and 2‐(5‐benzyloxy‐1‐methylindole) carboxyaldehyde (17) is reported. Compounds 1–15 have been designed as potential monoamine oxidase A and B inhibitors.
On the reaction of 3‐nitro‐1,2‐phenylenediamine with ethyl acetoacetate. Condensed dihydrodiazepinones
Authors: Puodžiūnaitė Benedikta , Kosychova Lidija , Stumbrevičiūtė Zita , Jančienė Regina , Talaikytė Zita 
Published: March 2009

AbstractCondensation of 3‐nitro‐1,2‐phenylenediamine with ethyl acetoacetate in boiling xylene gave two isomeric 2,3‐dihydro‐4‐methyl‐9‐nitro‐ and 2,5‐dihydro‐4‐methyl‐6‐nitro‐1H‐1,5‐benzodiazepin‐2‐ones, the 9‐nitro derivative thermal rearrangement product N‐isopropenyl‐4‐nitrobenzimidazolone and a non cyclic acetoacetamide derivative. At room temperature these reactants afforded 2,3‐dihydro‐2‐ethoxycarbonyl‐methyl‐2‐methyl‐4‐nitrobenzimidazole.
6,16‐methano‐6H,16H‐[2,4]benzothiazepino[3,4‐d][1,3,5]benzoxadiazocine and 6,26:13,19‐dimethano‐6H,9H,13H,19H,22H,26H‐benzo[1″,2″:5,6;4″,5″:5′,6′]bis[1,3]thiazepino[2,3‐d:2′,3′‐d]bis[1,3,5]‐benzoxadiazocine: New heterocyclic systems
Authors: Světlík Jan , Liptaj Tibor 
Published: March 2009

AbstractCyclization reactions of oxygen‐bridged pyrimidinethione 1a with 1,2‐bis(bromomethyl)benzene and 1,2,4,5‐tetrakis(bromomethyl)benzene leading to conformationally restricted benzothiazepine derivatives were examined. Molecular conformations of the products were studied by 1D and 2D nmr spectroscopy and with the help of semiempirical calculations.
Separation, structural determination and biological evaluation of the thymidylate synthase inhibitor 3,3‐Di‐(4′‐hydroxyphenyl)‐6(7)‐chloro‐1‐oxo‐1H,3H‐naphtho[1,8‐cd]pyran
Authors: Costi M. Paola , Tondi Donatella , Pecorari Piergiorgio , Rinaldi Marcella , Celentano Giuseppe , Ghelli Stefano , Antolini Luciano , Barlocco Daniela 
Published: March 2009

AbstractThe chloro substituted 3,3‐di‐(4′‐hydroxyphenyl)‐1‐oxo‐1H,3H‐naphtho[1,8‐cd]pyran was synthesized in a 40/60 mixture of C6 or C7 substituted isomers, respectively. The two isomers were separated by hplc. The X‐ray crystal structure of the mixture was obtained. Both the mixture and the single isomers were tested against Lactobacillus Casei thymidylate synthase. The X‐ray analysis clearly revealed co‐crystallization of the two isomeric species. The apparent Ki of the mixture was 0.8 muM, while those of the C6 and C7 substituted isomers were 0.42 and 0.52 muM, respectively, thus showing that the position of the chlorine in the naphthalene ring was not critical for enzymatic activity.
On the reaction of meldrum's acid with N‐trimethylsilylanilines substituted by electron withdrawing groups
Authors: Roche Sandrine , Yous Saïd , Couturier Daniel , Rigo Benoît 
Published: March 2009

AbstractThe reaction of Meldrum's acid with silylated anilines substituted by an electron withdrawing group easily yields the corresponding N‐phenyl malonamic acid, when the reaction is performed under high vacuum in dichlorobenzene.
Molecular structure and electronic spectrum of taspine: Semiempirical calculations
Authors: Sato Tsuguo , Kataoka Masahiro 
Published: March 2009

AbstractAM1 calculations show that taspine has the three energy‐minima along the rotation‐like nuclear displacement of the dimethylaminoethyl group. They correspond to two enantiomeric structures and a Cs structure, which have nearly equal energies. The energy barrier between the enantiomeric structures and the Cs structure is calculated to be about 1 kcal/mol. The small barrier readily causes an intramolecular interconversion of the two enantiomers through the Cs structure and thus results in the optical inactivity of taspine. CNDO/S calculations show that the electronic spectra of the enantiomer and the Cs structure are quite similar. These calculated spectra are in good agreement with the observed electronic spectra.
Solvent‐free synthesis of heterocyclic compounds using microwaves
Authors: Varma Rajender S. 
Published: March 2009

AbstractMicrowave‐enhanced solvent‐free synthetic approach is described that features simplicity, manipulative ease of the operation and conservation of solvents as the main advantages. This eco‐friendly approach, which has found application in facile organic functional group transformations, is applied to rapid assembly of heterocyclic compounds. A variety of solid state reactions are described that occur rapidly at ambient pressure under solventless conditions and provide ready access to intermediates such as enamines and α‐tosyloxyketones which can be transformed in situ to biologically significant heterocyclic compounds such as isoflav‐3‐enes, flavones, quinolones, 2‐aroylbenzo[b]furans and thiazoles in one‐pot operation. Multicomponent reactions under these solvent‐free conditions can be adapted for high speed parallel synthesis and are exemplified by assembly of dihydropyrimidine‐2(1H)‐ones (Biginelli reaction) and imidazo[1,2‐a]annulated pyridines, pyrazines and pyrimidines (Ugi reaction) which may have potential in building a library of such compounds.
Spectroscopic analysis of imidazolidines. Part I: Electron impact mass spectrometry
Authors: Salerno Alejandra , Hedrera Monica E. , Perillo Isabel A. , D'Accorso Norma B. , Alho Miriam Martins 
Published: March 2009

AbstractThe electron impact mass spectral fragmentation pathways for a series of 1,3‐di‐ and 1,2,3‐trisubstituted imidazolidines were investigated. The data show remarkable differences depending on the location and identity of substituents. The atypical 1,2,2,3‐tetrasubstituted imidazolidine, 2‐cyano‐1‐methyl‐3‐(p‐nitro‐phenyl)‐2‐phenylimidazolidine, was also investigated.
Preparation of 1‐substituted‐5‐[(2‐oxo‐2‐phenyl)ethyl]imidazoles
Authors: Aulaskari Paula , Ahlgrén Markku , Vainiotalo Pirjo , Pohjala Esko 
Published: March 2009

AbstractNew high yield preparation methods were developed for the pharmaceutically interesting compounds, 1‐benzyl‐, 1‐methyl‐, and 1H‐5‐[(2‐oxo‐2‐phenyl)ethyl]imidazoles 1a‐c, respectively. The title compounds were synthesized by four different methods using various starting materials. Two of the methods involved transformation reactions of the key intermediates, 1‐substituted‐5‐[(2‐nitro‐2‐phenyl)ethenyl]imidazoles 2a‐c and 1‐substituted‐5‐[(2‐nitro‐2‐phenyl)ethyl]imidazoles 3a‐c, while the other two utilized the oxidation of 1‐substituted‐5‐[(2‐hydroxy‐2‐phenyl)ethyl]imidazoles 4a‐c, with chromic oxide, and the umpolung reaction of benzaldehyde followed by a condensation reaction of the umpolung intermediate with imidazolecarboxaldehydes 6a‐c.
Formation of a σ‐complex from dicyanopyridinyl and hydroxyalkyl radicals. An ESR study of the photoinitiated complex forming reactions of aryl ketones with 2,4‐pyridinedicarbonitrile and alcohols
Authors: Vittimberga Bruno M. , Rieger Anne L. 
Published: March 2009

AbstractWhen a 1° or 2° alcohol solution of benzophenone and 2,4‐pyridinedicarbonitrile (1) is irradiated, the 2,4‐dicyanopyridinyl radical (2) is formed immediately. When the irradiation is performed in the cavity of an ESR spectrometer, the spectrum amplitude increases to a near steady‐state level, α. When the illumination is discontinued, a sharp rise in amplitude is observed to the β level. These results can be interpreted in terms of an equilibrium between free 2 and an ESR‐silent complex of 2 (concentrations proportional to α and β ‐ α, respectively) with Keq = (β ‐ α)/α. The unprecedented increase in signal amplitude when irradiation is stopped requires an alcohol; the effect is not observed when other solvents are used. Keq was found to correlate with the steric bulk of the alcohol solvent. These and other results lead to the conclusion that hydroxyalkyl radicals react reversibly with 2 to form the ESR‐silent complex.
Effect of mixtures of water and organic solvents on the acidities of 5‐membered heteroaromatic carboxylic acids
Authors: Lee Chang Kiu , Jeoung Eun Hee , Lee In‐Sook Han 
Published: March 2009

AbstractpKa values of various 5‐membered heterocyclic aromatic carboxylic acids (pKas) were determined in solutions of 20.3, 35.2, 50.1, 65.1, and 79.9 weight percent of organic solvents in water. The pKas values show good linearity when they are ploted as a function of the dielectric constants of the mixed solvents methanol, ethanol, isopropyl alcohol, and tert‐butyl alcohol. On the other hand, the pKas values show a poor correlation with the dielectric constants in aqueous acetonitrile, N,N‐dimethylformamide, dimethyl sulfoxide, and dioxane. The pKa values in pure water and in pure organic solvent could be calculated by extrapolation of the plot of the pKas versus percentage of organic solvent. The pKas values of 4‐ and 5‐sub‐stituted 2‐thiophenecarboxylic acids were also determined, and the ρ values are calculated in the same series of the solvents.
An interesting synthesis of thieno[2,3‐d][1,2,3]thiadiazole via decomposition/recyclization of 3‐methoxycarbonyl‐1H‐thieno‐[2,3‐e][1,3,4]thiadiazine 4,4‐dioxide
Authors: Stephens Chad E. , Sowell J. Walter 
Published: March 2009

AbstractAttempted hydrolysis of the ester of 3‐methoxycarbonyl‐1H‐thieno[2,3‐e][1,3,4]thiadiazine 4,4‐dioxide (I) under acidic conditions gave the ring‐contracted thieno[2,3‐d][1,2,3]thiadiazole (V) instead of the expected carboxylic acid. In addition to a discussion of the reaction, a plausible mechanism is presented.
1,2‐Methyl shift in the reaction of 4,7‐dihydro‐4,5‐dimethyl‐7‐phenyl‐(1,2,4)‐triazolo[1,5‐a]pyrimidine with tosyl azide
Authors: Komykhov Sergey A. , Desenko Sergey M. , Kaganovsky Alexander S. , Orlov Valery D. , Meier Herbert 
Published: March 2009

AbstractThe reaction of the heterocyclic enamine 1 with tosyl azide (2) leads to the tosylimino derivative 4 of 1,2,4‐triazolo[1,5‐a]pyrimidine. The extrusion of nitrogen from the primary adduct 3 is followed by a 1,2‐shift of a methyl group. The structure determination of 4 is based on 1H and 13C nmr spectra including NOE measurements.
Synthesis of 2‐aminoquinazolinc‐4(3H)‐one derivatives as potential potassium channel openers
Authors: Erb BÉNÉDicte , Akue Rufine , Rigo Benoît , Pirotte Bernard , Couturier Daniel 
Published: March 2009

AbstractStarting from 2‐thioxoquinazolin‐4‐one, the synthesis of 2‐amino‐4(3H)‐one derivatives, structurally related to potassium channels openers pinacidil and diazoxide, is described.
The crystal structure of 9‐chloro‐4,5‐dihydro‐2‐ethyl‐1‐(2,4,6‐trichlorophenyl)‐1H‐1,2,4‐triazolo[3,2‐d][1,5]‐benzoxazepinium hexachloroantimonate
Authors: Liu Xianjun , Liu Yi , Ding Zongbiao , Wang Quanrui , Zhang Chengzhi 
Published: March 2009

AbstractThe title compound 4, i.e. 9‐chloro‐4,5‐dihydro‐2‐ethyl‐1‐(2,4,6‐trichlorophenyl)‐1H‐1,2,4‐triazolo[3,2‐d]‐[1,5]benzoxazepinium hexachloroantimonate, is a novel 6‐7‐5 tricyclic heterocycle. C18H14Cl4N3O·SbCJ6, M = 764.61, P21/c(#14), a = 13.457(4), b = 11.583(2), c = 18.992(3) Å α = 90, β = 110.11(1)°, Z = 4, V = 2780(1) Å3, Dc = 1.827 g/cc, μ (MoKα) = 19.69 cm−1, F(000) = 1488.00, T = 293 K, Rint = 0.055 for 3094 independent reflections with I>3.00σ(I). The five‐membered heterocyclic ring is nearly planar, with the trichlorophenyl ring at N(2) almost perpendicular to it. However, the seven‐membered ring is not planar, but adopts a twist‐boat conformation.
Polar aspects of intramolecular interactions in 2‐amino‐5‐nitro‐4‐methylpyridines and 2‐amino‐3‐nitro‐4‐methylpyridines
Authors: Wandas M. , Puszko A. , Pawelka Z. 
Published: March 2009

AbstractThe dipole moments of twelve 2‐N‐substituted amino‐5‐nitro‐4‐methylpyridines (I‐XII) and three 2‐N‐substituted amino‐3‐nitro‐4‐methylpyridines (XIII‐XV) were determined in benzene. The polar aspects of intramolecular charge‐transfer and intramolecular hydrogen bonding were discussed. The interaction dipole moments, μint, were calculated for 2‐N‐alkyl(or aryl)amino‐5‐nitro‐4‐methylpyridines. Increased alkylation of amino nitrogen brought about an intensified push‐pull interaction between the amino and nitro groups. The solvent effects on the dipole moments of 2‐N‐methylamino‐5‐nitro‐4‐methyl‐(I), 2‐N,N‐dimethylamino‐5‐nitro‐4‐methyl‐ (II) and 2‐N‐methylamino‐3‐nitro‐4‐methylpyridines (XIII) were different. Specific hydrogen bond solute‐solvent interactions increased the charge‐transfer effect in I, but it did not disrupt the intramolecular hydrogen bond in XIII.
Unusual behaviour of N‐cinnamoyl‐2‐hydroxy‐2‐(trifluoromethyl)‐arylethylamines in pictet‐gams cyclization. Synthesis of 2‐styryl‐5‐aryl‐5‐trifluoromethyl‐2‐oxazolines
Authors: Poszávácz LÁSzlÓ , Simig Gyula 
Published: March 2009

AbstractCyclization of N‐acyl‐2‐hydroxy‐2‐(trifluoromethyl)arylethylamines 4 under Pictet‐Gams conditions afforded 2‐oxazolines 5 instead of the expected isoquinolines 6. The effect of the trifluoromethyl group on the result of the reaction is discussed.
Studies on the chemistry of thienoannelated O,N‐ and S,N‐containing heterocycles. 17. Preparation of 1H‐thieno[2,3‐b][1,4]thiazine‐1‐carboxarnides as smooth muscle relaxants
Authors: Schreder Maria E. , Erker Thomas 
Published: March 2009

AbstractA new series of substituted thieno[1,4]thiazines with an urea moiety has been designed. The synthesis and results of replacement of the quinoline and indoline moieties of lead structure 1 are described. The key step in preparation was the substitution with 4‐nitrophenyl chloroformate to obtain the required reactivity for substitution with diamines. Structural modifications of the amino side chain with the aim of finding tissue specific compounds were carried out. Pharmacological testings explored the presumed calcium‐channel‐antagonistic and potassium‐channel‐opening activities.
Synthesis of new thieno and pyrazolo[2,1]benzothiazepine derivatives with potential antidepressant properties
Authors: Vega S. , Díaz J. A. , Darias V. , Mateo C. C. SÁNchez 
Published: March 2009

AbstractIn this paper we describe a series of new thieno and pyrazolo[2,1]benzothiazepine derivatives 7a‐o which were synthesized by two different methods both starting from the previously described tricyclic alcohols 1–3. Several components of this series were effective p. o. (per os, orally) in different pharmacological tests currently employed in the evaluation of antidepressant activity.
Reaction of 4,5,6‐triaminopyrimidine and 2,4,5,6‐tetraaminopyrimidine with 3‐dimethylaminopropiophenones. Synthesis of new 4‐aryl‐2,3‐dihydropyrimido[4,5‐b][1,4]diazepines
Authors: Braulio Insuasty O. , Henry Insuasty I. , Jairo Quiroga P. , Saitz Claudio , Jullian Carolina 
Published: March 2009

AbstractSeveral new 6‐amino‐ and 6,8‐diamino‐4‐aryl‐2,3‐dihydropyrimido[4,5‐b][1,4]diazepines were obtained from the reaction of 4,5,6‐triaminopyrimidine 1a and 2,4,5,6‐tetraaminopyrimidine 1b with one equivalent of 3‐dimethylaminopropiophenones 2 in absolute ethanol. Structure analysis of 6‐amino‐ and 6,8‐diamino‐4‐aryl‐2,3‐dihydropyrimido[4,5‐b][1,4]diazepines 3a‐i, determined by detailed nmr measurements, reveals a high regioselectivity of this reaction.