bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and thermolysis of the 2,3‐dihydro‐1H‐pyrole‐2,3‐diones, pseudopericyclic reactions of formyl(N‐phenylimidoyl)ketene: Experimental data and PM3 calculations
Authors: Saripinar Emin , Karataş Süleyman 
Published: March 2009

AbstractThe reactions of the 2,3‐dihydro‐1H‐furan‐2,3‐dione 1 with Schiff bases 2a‐f at 60–70°C furnish the corresponding 2,3‐dihydro‐1H‐pyrole‐2,3‐diones 3a‐f. The heating of 3a‐d afforded the corresponding 4‐methoxybenzoyl(N‐arylimidoyl)k:etenes 4a‐d as intermediates which undergo a very facile cyclization to quinoline‐4‐ones 5a‐d. According to our PM3 calculations, fragmentation of 4‐formyl‐2,3‐dihydro‐1H‐pyrole‐2,3‐dione and 1,4‐cyclization of formyl(N‐phenylimidoyl)k:etene IN1 to azetin‐2‐one IN2 and oxe‐tone IN3 are pseudopericyclic reactions with two orbital connections, proceed via planar transition structures. Due to to the possibility of syn and anti conformations of the imine phenyl, there are eight E/Z‐iso‐mers of IN1. In addition, we have also calculated reaction mechanism of formation of quinoline‐4‐ones by the PM3 method.
Gem‐disubstituted 4‐oxocyclohexanes: Source for spiro heterocycles
Authors: Padmavathi Venkatapuram , Basha Shaik Mahaboob , Subbaiah Dandu Rangayapalle Chinna Venkata , Reddy Tippireddy Venkata Ramana , Padmaja Adivireddy 
Published: March 2009

AbstractNovel spiro heterocycles, substituted spiro‐pyrimidine, pyrazole and isoxazole compounds are prepared by the cyclocondensation of 4‐oxocyclohexane gem‐dicarboxylates and cyano esters with nucleophiles.
Synthesis of macrocycles incorporating azo‐bis(azofurazan) framework
Authors: Sheremetev A. B. , Ivanova E. A. , Dmitriev D. E. , Kulagina V. O. , Averkiev Boris B. , Antipin Mikhail Yu. 
Published: March 2009

AbstractA series of macrocycles containing four furazan rings bonded by three azo bonds 2, 5 and 7 have been synthesized from the common precursor, 3‐amino‐3′‐nitro(azofurazan) 3. The macrocycles closure is a result of NN bond formation at oxidative cyclization of corresponding bis(3‐aminofurazan‐4‐yl) precursors. X‐Ray crystal structures of macrocycles 2, 2•AcOH, 11 and 13 are reported.
Aromatization and ring cyclization: A better understanding on the ring cyclization mechanism of 3‐amino‐6‐hydrazino‐1,2,4‐triazin‐5(2H)‐one reacted with acetic acid in N,N‐dimethylformamide
Authors: Hwang Long‐Chih , Wu Rang‐Rong , Tu Chun‐Hsien 
Published: March 2009

AbstractIn this paper we report that the title compound (3) reacts with excess N,N‐dimethylformamide (DMF) containing two equivalents of acetic acid to afford 6‐amino‐1,2,4‐triazolo[3,4‐f][1,2,4]triazin‐8(7H)‐one (1). When 3‐amino‐2‐benzyl‐6‐hydrazino‐1,2,4‐triazin‐5(2H)‐one (6), the N‐2 benzylated derivative of 3, is treated under the same conditions, ring cyclization does not occur; instead, 3‐amino‐2‐benzyl‐6‐(2‐formyl‐hydrazino)‐1,2,4‐triazin‐5(2H)‐one (7) is formed. Single‐crystal X‐ray analysis of a 3‐ethyl derivative of compound 1 reveals the predominant tautomeric structure to be the 7H‐tautomer (7H‐1). From these results, we propose a reasonable cyclization mechanism that incorporates two important points: (1) the tautomerism of the N‐2 hydrogen with the C‐5 oxo group aromatizes the 1,2,4‐triazine ring, and (2) the DMF is proto‐nated by acetic acid on the nitrogen atom, then deamination occurs where DMF is attacked by the 6‐hydrazino group of 3 or 6.
Synthesis of novel 4‐pyrazolyl‐2‐oxo‐1,2,3,4‐tetrahydropyrimidines promoted by phosphotungstic acid
Authors: Sivaprasad Ganesabaskaran , Peramal Paramasivan T. 
Published: March 2009

AbstractPhosphotungstic acid, a keggin's type heteropoly acid catatalysed Biginelli reaction was carried out using pyrazole aldehyde, ethyl acetoacetate and urea to synthesis novel 4‐pyrazolyl ‐2‐oxo‐1,2,3,4‐tetrahydropy‐ rimidines.
A study of substituent effect on 1H and 13C NMR spectra of mono, di and poly substituted carbazoles
Authors: Bonesi Sergio M. , Ponce Maria A. , Erra‐Balsells Rosa 
Published: March 2009

Abstract1H and 13C NMR spectra of several substituted carbazoles (Series 1, 2, 3, 4 and 5) were measured. Substituent chemical shifts (SCS's) and Lynch correlations of 1H and 13C nuclei were calculated and the substituent effect on the NMR phenomena was determined. Atomic charge densities for carbazoles of Series 1, 2, 3, 4 and 5 were calculated by using the semi empirical PM3 method. These values also show a linear correlation with the 13C chemical shifts.
A new method for the generation of α‐nitrosoolefins from ketooximes and its application to the synthesis of 5,6‐dihydro‐4H‐1,2‐oxazine derivatives
Authors: Gaonkar S. L. , Rai K. M. Lokanatha 
Published: March 2009

AbstractReaction of ketooximes containing α‐methylene group with chloramine‐T followed by treatment with tri‐ethylamine leads to the formation of α‐nitrosoolefins via α‐nitrosochloride, which can react in situ intermol‐ecularly with olefinic compounds to produce 5,6‐dihydro‐4H‐1,2‐oxazine derivatives in good yield.
Synthesis and prediction of bioactivity of new nitroimidazole derivatives
Authors: Kowalski Piotr , Nowak Krystyna , Szpakiewicz Barbara 
Published: March 2009

AbstractSyntheses of 1‐propyl derivatives of 2‐methyl‐5‐nitroimidazole (11‐17), containing various azanaphtha‐lene systems attached at 3‐position of the propyl group have been described. Due to structural similarity of the derivatives 11‐17 with metronidazole, an antibacterial and antiprotozoal drug, pharmacological properties of the target compounds were predicted using the PASS program. Polar surface area (PSA) parameter was also applied for estimation of the physical properties of 11‐17 as drug‐like candidates.
A convenient, rapid, and highly selective method for synthesis of new pyrazolo[1,5‐a]pyrimidines via the reaction of enaminones and 5‐amino‐1H‐pyrazoles under microwave irradiation
Authors: Ming Li , Shuwen Wang , Lirong Wen , Huazheng Yang , Xiuli Zhang 
Published: March 2009

AbstractTwelve new 7‐aryl‐3‐cyanopyrazolo[1,5‐a]pyrimidines (3a‐f) and ethyl 7‐arylpyrazolo[1,5‐a]pyrimidine‐3‐carboxylates (3g‐l) have been conveniently synthesized by the reaction of enaminones with 5‐amino‐1H‐pyrazoles in good yields under microwave irradiation. With one substituded enaminone, only one regioiso‐mer was obtained. The structures of new compounds were fully confirmed by elemental analysis, ir, 1H nmr and X‐ray diffraction (XRD) analysis. A plausible reaction mechanism for the synthesis of title compounds is presented. The antifungal activities of some compounds are also reported.
Studies with quinolines: New synthetic routes to 4H,5H,6H,9H‐benzo[ij]pyrano[2,3‐b]quinolizine‐8‐one, 4H‐pyrano[2,3‐b]pyridine, 2H‐pyran‐2‐one and pyranopyridoquinoline derivatives
Authors: El‐Taweel Fathy Mohamad Abdel Aziz 
Published: March 2009

AbstractSeveral new benzo[ij]pyrano[2,3‐b]quinolizine‐8‐ones 5 and 4H‐pyrano[2,3‐b]pyridine 8 derivatives were synthesized from 4‐hydroxyquinolines 1. Reacting 3‐acetyl‐4‐hydroxy‐1‐phenyl‐1H‐quinoline‐2‐one with dimethylformamide dimethylacetal afforded 3‐(3‐Dimethylarnino‐acryloyl)‐4‐hydroxy‐1‐phenyl‐1H‐quinolin‐2‐one 9. This reacted with hippuric acid and diethyl 3‐oxoglutarate to give 2H‐pyran‐2‐one 13 and pyranopyridoquinoline 17 respectively.
Synthesis and 1H NMR structural analysis of 11‐aryl/heteroarylnaphtha[2,1‐b]furans: X‐ray crystal structure of 11‐(4′‐pyridyl)naphtho[2,1 ‐b]furan
Authors: Mashraqui Sabir H , Patil Mamta B , Sangvikar Yogesh , Ashraf Mohamed , Mistry Hitesh D , Dâub Elise Trân Huu , Meetsma Auke 
Published: March 2009

AbstractSynthesis of biaryl type systems, 11‐aryl/heteroarylnaphtho[2,1‐b]furans 8‐11 has been described with a view to studying the conformational orientation of C‐11 aryl/heteroaryl groups. Synthesis of 8‐11 was accomplished by a two‐step sequence involving O‐alkylation of 2‐naphthol with appropriate halo‐ketones 2‐4, followed by cyclization of the resulting naphthoxy‐ketones 5‐7 with methanesulphonic acid. The structures of 8‐11 are based on detailed 2D NMR spectral analysis. The H8 in these compounds is not subject to significant anisotropic upfield shielding effects. The slightly upfield chemical shift of H8 in molecules 9‐11, relative to 8 has been correlated with the electron density at C17 and C8 positions. While molecular modeling indicated dihedral angle (φ) between the C11 aryl/heteroaryl groups and the naphthofuran plane to be in the range of 70–60° in 8‐10, a single X‐ray crystal structural analysis of 11‐(4′‐pyridyl)naphtho[2,1‐b]furan 10 indicated (φ) of 64.36°. In view of significant deviations from the orthogonal oreintation, the absence of any significant anisotropic shielding in 8‐11 is not entirely unexpected.
Synthesis of hantzsch 1,4‐dihydropyridines under solvent‐free condition using zn[(L)proline]2 as lewis acid catalyst
Authors: Sivamurugan V. , Kumar R. Suresh , Palanichamy M. , Murugesan V. 
Published: March 2009

AbstractThe present short communication describes a Lewis acid (Zn[(L)proline]2) catalysed one pot synthesis of Hantzsch 1,4‐dihydropyridine (DHP) derivatives under solvent‐free condition by conventional heating and microwave irradiation. The Lewis acid catalyst Zn[(L)proline]2 used in this reaction afford moderate to good yield. The catalyst is reusable upto five cycles without appreciable loss of its catalytic activity.
Synthesis and antiviral evaluation of some carbonucleoside analogues
Authors: Alho Miriam A. Martins , Errea Maria I. , Sguerra Vanesa L. , D'Accorso Norma B. , Talarico Laura B. , García Cybele C. , Damonte Elsa B. 
Published: March 2009

Abstract1,2‐O‐Isopropylidene‐α‐L‐threofuranosyl heterocyclic derivatives were synthesized from 1,2‐O‐iso‐propylidene‐α‐D‐xilopentadialdo‐1,4‐furanose and tested for antiviral activity against herpes simplex virus type 1, dengue virus type 2 and Junin virus. For comparative propose, the antiviral activity of some of their pyranosyl analogues were also tested. The furanosyl derivatives showed to be moderate inhibitors of Junin virus and, in general, proved to be more effective than the pyranosyl analogues.
Rapid synthesis of 2,5‐disubtituted 1,3,4‐thiadiazoles under microwave irradiation
Authors: Lebrini Mounim , Bentiss Fouad , Lagrenée Michel 
Published: March 2009

AbstractThe one pot, three‐components condensation of aromatic aldehydes, hydrazine and sulfur in ethanol under microwave irradiation provided symmetrically 3,5‐disubstituted 1,3,4‐thiadiazoles in high yields and good purity. This reaction must be conducted under pressure of hydrogen sulfide produced in‐situ. The structure of the compounds was confirmed by 1H, 13C NMR, MS and elemental analysis.
Heterocyclic synthesis: A convenient route to some 2‐mercepto 1,3,4‐oxadiazole and green chemistry microwave‐induced one‐pot synthesis of 2‐aryl 1,3,4‐oxadiazole in quinazolone and their antibacterial and antifungal activity
Authors: Desai A. R. , Desai K. R. 
Published: March 2009

AbstractSeveral 6‐substituted‐3‐[(5‐mercepto‐1,3,4‐oxadiazol‐2‐yl)methyl]‐2‐substituted quinazolin‐4(3H)‐one or 6‐substituted‐3‐[4‐(5‐mercepto‐1,3,4‐oxadiazol‐2‐yl)phenyl]‐2‐substituedquinazolin‐4(3H)‐one 2(a‐l) and 6‐substituted‐3‐[(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl)methyl]‐2‐substitutedquinazolin‐4(3H)‐one or 6‐substi‐tuted‐3‐[4‐(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl) phenyl]‐2‐substitutedquinazolin‐4(3H)‐one 3(a‐l) were synthesized using conventional and microwave techniques respectively and were screened for antibacterial and antifungal activity.
Copper dipyridine dichloride as a mild and efficient catalyst for a one pot condensation bigenelli reaction
Authors: Kumar V. Naveen , Someshwar P. , Reddy P. Narsimha , Reddy Y. Thirupathi , Rajitha B. 
Published: March 2009

AbstractThe condensation reaction of aldehydes, β‐ketoesters and urea/thiourea in presence of a catalytic amount of CuPy2Cl2 complex proceeded under very mild reaction conditions in high yield (80‐90%).
Synthesis of 1,2,4‐triazolo[1,5‐d]‐1,2,4‐triazine‐5‐thiones
Authors: Heravi Majid M. , Montazeri Naser , Rahimizadeh Mohammad , Bakavoli Mehdi , Ghassemzadeh Mitra 
Published: March 2009

AbstractIn an attempt to discover bicyclic compounds containing the 1,2,4‐triazine moiety, 1,2,4‐triazolo[1,5‐d]‐1,2,4‐triazine‐5‐thiones from one pot reaction of arylnitriles with 4‐amino‐1,2,4‐triazine‐3‐thione‐5‐one in the presence of potassium tert‐butoxide were synthesized.
Synthesis of some new substituted ethanone hydrazones containing 1H‐1,2,4‐triazole and thiazole
Authors: Liu Fang‐Ming , Sun Ya‐Dong , Xie Zheng‐Feng 
Published: March 2009

AbstractThree new thiosemicarbazones have been synthesized by condensation reaction of 2‐bromo‐1‐arylethanones with thiosemicarbazide, which reacted with various 2‐bromo‐1‐arylethanones in ethanol under refluxing to give a series of substituted ethanone hydrazone derivatives. Their structures were confirmed by elemental analysis, IR, 1H NMR, and MS spectra.
Synthesis and intramolecular cyclization of 2‐methylsulfany‐4‐oxo‐3(4H)‐quinazolinyl)acetohydrazide
Authors: Burbuliene Milda M. , Bobrovas Olegas , Vainilavicius Povilas 
Published: March 2009

Abstractmagnified imageTreatment of ambident sodium salt of 2‐methylsulfanyl‐4(3H)‐quinazolinone with methyl bromoacetate resulted in N(3)‐alkyl ester formation. Reaction of the resulted ester with hydrazine hydrate gave 2‐methylsulfanyl‐4‐oxo‐3(4H)‐quinazolinyl)acetohydrazide, which underwent intramolecular cyclization under heating in dimethylformamide to give 1‐aminoimidazo[2,1‐b]quinazoline‐2,5(1H,3H)‐dione. The latter took place in acylation reaction and in condensation with aromatic aldehydes.
Preparation of 6‐azaoxindole (6‐azaindol‐2(3H)‐one) and substituted derivatives
Authors: Andreassen Einar J. , Bakke Jan M. 
Published: March 2009

Abstractmagnified imageA general synthesis of 6‐azaoxindoles, substituted in the 3‐ and 5‐position, has been developed starting from 4‐methoxycarbomethyl‐3‐nitropyridine, via hydrogenation of the nitro group and cyclisation of the resulting 3‐amino‐4‐methoxycarbomethyl‐pyridine.
Regioselective synthesis of novel spiroheterocyclic framework via the 1,3‐dipolar cycloaddition
Authors: Hu Xiaofen , Feng Yaqing , Qiao Kangjian , Zhou Weiyi 
Published: March 2009

Abstractmagnified imageA series of novel dispiro[oxindole‐fused pyrimidine]pyrrolidine ring systems 4a‐f were synthesized by the regioselective 1,3‐dipolar cycloaddition reaction of the 2‐arylmethylene‐7‐benzyl‐9‐(benzylidene)tetrahydropyrido[4,3‐d]thiazolo[3,2‐a]pyrimidin‐3‐ones 1a‐f with azomethine ylides, generating by the decarboxylative route from isatin 2 and sarcosine 3, in moderate to good yields. The regiochemistry of designed dispiroheterocyclic compounds 4a‐f was established by single crystal X‐ray structure and spectroscopic techniques.
Synthesis of new double (spin and fluorescence) sensor reagents and labels
Authors: Bognár Balázs , Øz Erzsébet , Hideg Kálmán , Kálai Tamás 
Published: March 2009

Abstractmagnified imageNew double (spin and fluorescence) sensors were synthesized from aminocoumarin, pyrene and 4‐nitrobenzofurazan dyes and from five‐ or six‐membered nitroxides or their diamagnetic derivatives with aromatic nucleophylic substitution, Suzuki cross‐coupling reaction and acylation reactions. The new compounds exhibit fluorescence emission between 382‐529 nm affording various utilization possibilities.
Synthesis of 2‐amino‐s‐triazino[1,2‐a]benzimidazoles as potential antifolates from 2‐guanidino‐ and 2‐guanidino‐5‐methylbenzimidazoles
Authors: Dolzhenko Anton V. , Chui Wai‐Keung 
Published: March 2009

Abstractmagnified imageThe syntheses of 2‐amino‐s‐triazino[1,2‐a]benzimidazoles from 2‐guanidinobenzimidazoles were successfully carried out by a ring annelation reaction. The regiochemistry of the ring closure of 5‐methyl‐2‐guanidinobenzimidazole with diethyl azodicarboxylate, aldehydes, acetone, diethyl ethoxymethylenemalonate and orthoesters, leading to the formation of s‐triazine ring was studied. High regioselectivity was not observed in any of these reactions. However, the synthesis of s‐triazino[1,2‐a]benzimidazole system was found to be more regioselective than its 3,4‐dihydro analogue. NOESY experiment indicated that the compound, 2‐amino‐4,4‐dimethyl‐3,4‐dihydro‐s‐triazino[1,2‐a]benzimidazole existed predominantly as the 3,4‐dihydro tautomer in dimethyl sulfoxide. It was found to inhibit bovine dihydrofolate reductase with IC50 10.9 μM.
Synthesis of quinolin‐4‐yl substituted malonates, cyanoacetates, acetoacetates and related compounds
Authors: Stadlbauer Wolfgang , Täubl Anna E. , Dang Hoai V. , Reidlinger Claudia , Zangger Klaus 
Published: March 2009

Abstractmagnified image4‐Chloro‐ or 4‐tosyloxyquinolines 1 and 10 react with CH‐acidic compounds such as malonates 2a,b, ethyl cyanoacetate (2c), malononitrile (2d), ethyl acetoacetate (2e), acetylacetone (2f) or dimedone (2g) under mild conditions and good yields to quinolin‐4‐yl substituted derivatives 3‐8 and 11. With 3‐phenylsulfonylquinolones 1i‐k a redox reaction to 2‐hydroxy‐2‐quinolin‐4‐yl‐malonates 9 was observed. Amination of 3‐nitroquinolinyl malonate 3f leads to malonester‐amides 13 and 14.
Racemic and diastereoselective synthesis of aryl and heteroaryl tetrahydroisoquinolines via the pictet‐spengler reaction
Authors: Aubry Sylvain , Pellet‐Rostaing Stéphane , Lemaire Marc , Faure René 
Published: March 2009

Abstractmagnified imageNew tetrahydroisoquinolines were synthesized by the Pictet‐Spengler reaction. Influence of a wide range of aryl and heteroaryl aldehydes, was investigated in the cyclization step with 3,4‐dimethoxyphenylethylamine 1, L‐DOPA 2 and L‐3,4‐dimethoxyphenylalanine methyl ester 3. Compounds 2 and 3 served as probes to assess the efficiency of two Pictet‐Spengler reactions with respect to their diastereoselectivity, in order to obtain optically active diastereoisomers. Cis‐ and trans‐diastereoisomers were obtained in short reaction times with moderate to good isolated yields (20‐79%). Both nmr and X‐ray analyses confirmed the expected diastereoisomer configurations.
Synthesis and characterization of 4‐aryl‐5‐(1‐aryl‐2‐methyl‐2‐nitropropyl)‐1,2,3‐selenadiazoles
Authors: Saravanan Sivaperuman , Nithya Arumugam , Muthusubramanian Shanmugam 
Published: March 2009

Abstractmagnified imagemagnified imageThe synthesis of a new set of selenadiazoles, 4‐aryl‐5‐(1‐aryl‐2‐methyl‐2‐nitropropyl)‐1,2,3‐selenadiazoles (4) derived from 2‐[4‐methyl‐4‐nitro‐1,3‐diarylpentylidene]‐1‐hydrazinecarboxamide (3) has been reported. THF has been found to be the solvent of choice for this reaction. Structural features of 3 and 4 have been analyzed by NMR and X‐ray techniques.
Syntheses of armed‐macrocycles by reductive amination using NaBH(OAc)3 under 1 MPa
Authors: Habata Yoichi , Osaka Futoshi , Yamada Sachiko 
Published: March 2009

Abstractmagnified imageArmed‐monoaza‐12‐crown‐4, monoaza‐15‐crown‐5, diaza‐12‐crown‐4, diaza‐18‐crown‐6 ethers, and 1,4,7,10‐tetraazacyclododecane having aromatic pendants were prepared by the reductive amination of the corresponding macrocycles with aromatic carboxyaldehydes in the presence of NaBH(OAc)3. Reductive amination under 1 MPa conditions provided significant shortening of the reaction time and yield enhancements.
Unsymmetrical covariance processing of COSY or TOCSY and HSQC NMR data to obtain the equivalent of HSQC‐COSY or HSQC‐TOCSY spectra
Authors: Blinov Kirill A. , Larin Nicolay I. , Williams Antony J. , Mills Kent A. , Martin Gary E. 
Published: March 2009

Abstractmagnified imageArtifacts observed in the indirect covariance NMR spectrum of HSQC‐TOCSY data have recently been analyzed and a method for their elimination proposed. More recently, unsymmetrical covariance processing has been applied HSQC and HMBC spectral data to afford long‐range carbon‐carbon correlation information equivalent to that obtained from n, 1‐, 1, n‐ and m,n‐ADEQUATE spectra. We now wish to describe the results obtained through the application of unsymmetrical covariance processing of HSQC and COSY or TOCSY data, which affords the equivalent of HSQC‐COSY and HSQC‐TOCSY data in a fraction of the time required to record these spectra directly and with considerably higher sensitivity.
A mechanistic approach to photochemical behavior of 4‐anisyl‐4‐methyl‐2,6‐diphenyl‐4H‐thiopyran‐1,1‐dioxide
Authors: Rezanejadebardajee Ghasem , Jafarpour Farnaz , Pirelahi Hooshang 
Published: March 2009

Abstractmagnified imagePhotoisomerization of 4‐anisyl‐4‐methyl‐2,6‐diphenyl‐4H‐thiopyran‐1,1‐dioxide is described in the presence of a sensitizer and new mechanistic features are proposed. The relative molar ratios of the stereoselective photoproducts compared in the presence and the absence of sensitizer in different concentrations of the starting material using hplc. The results observed are discussed on the basis of a triplet excited state thiadi‐π‐methane rearrangement.
Reactions of cephalosporin sulfones 3. Synthesis of 2‐phenylhydrazonocephem‐sulfones. A new potential entry to 2‐aminocephems
Authors: Gunda Tamas E. , Batta Gyula 
Published: March 2009

Abstractmagnified imageReaction of cephem sulfones 1a‐e with aryldiazonium salts gives the 2‐azo compounds which immediately rearrange into the corresponding 2‐hydrazono derivatives 2a‐e.
Synthesis and activity of four (N,N‐dimethylamino)benzamide nonsteroidal anti‐inflammatory drugs based on thiazole and thiazoline
Authors: Lynch Daniel E. , Hayer Ravinder , Beddows Samantha , Howdle Joy , Thake C. Douglas 
Published: March 2009

Abstractmagnified imageFour compounds derived from 2‐aminothiazole and 2‐amino‐2‐thiazoline were prepared by coupling the respective bases with the acid chlorides of either 3‐ or 4‐(N,N‐dimethylamino)benzoic acid. Products were identified using infrared spectroscopy, 1H NMR spectroscopy and electrospray mass spectroscopy and in two cases by single‐crystal X‐ray diffraction. Of the four, N‐(thiazol‐2‐yl)‐3‐(N,N‐dimethylamino)‐benzamide (1), N‐(thiazolin‐2‐yl)‐4‐(N,N‐dimethylamino)benzamide (2), N‐(thiazolin‐2‐yl)‐3‐(N,N‐dimethylamino) benzamide (3) and N‐(thiazolin‐2‐yl)‐4‐(N,N‐dimethylamino)benzamide (4), the hydrochloride salts of compounds 3 and 4 showed anti‐inflammatory activity across a concentration range of 10−2−5 × 10−4 M while 3 (at a concentration of 10−5 M) was found to have no adverse effect on myocardial function. The X‐ray crystal structure of 2 and the 1:1 adduct structure of 3 with 3‐(N,N‐dimethylamino)benzoic acid are reported.
A series of 1‐[2‐aryl‐1‐diazenyl]‐3‐({3‐[2‐aryl‐1‐diazenyl]perhydrobenzo[d]imidazol‐1‐yl}methyl)perhydrobenzo[d]imidazoles. Synthesis and characterization
Authors: Glister Julie F. , Vaughan Keith 
Published: March 2009

Abstractmagnified imageReaction of diazonium salts with solutions of 1,2‐diaminocyclohexane mixed with formaldehyde affords the 1‐[2‐aryl‐1‐diazenyl]‐3‐({3‐[2‐aryl‐1‐diazenyl]perhydrobenzo[d]imidazol‐1‐yl}methyl)perhydrobenzo‐[d]imidazoles (6), a new series of bis‐triazenes with different connectivity than any previous type of bis‐triazene reported. The products have been characterized principally by NMR and IR spectroscopy, elemental analysis and unequivocally by X‐ray crystallography. The methylene protons of the perhydroimidazole rings are diastereotopic giving rise to a doublet of doublets pattern in the 1H NMR spectra. However, detailed analysis of the NMR spectra shows that there is more than one set of doublet‐of‐doublet signals, suggesting the presence of different rotameric forms of the products. The 13C NMR spectral assignments were assisted by COSY and DEPT experiments with selected compounds.
Application on novel fragmentation reaction: A concise synthesis of 2,3,5‐trisubstituted furans from butenolides
Authors: Zhang Xuqing , Jackson Elieen U. , Schultz Arthur G. 
Published: March 2009

Abstractmagnified imageButenolides 4, generated from a novel fragmentation reaction, function as excellent precursors to 2,3,5‐trisubstituted furans 5 by additions of alkyl or aryl metallic reagents. It can also be converted into siloxyfurans 6 by treatment with silylating reagents.