bluuebunny/crossref_metadata_2025_split huggingface dataset:
Random optimizations for direct heteronuclear correlations
Authors: Hadden Chad E. , Moon Joe B. , Hadden Daneen T. A. 
Published: March 2009

AbstractA novel optimization method is described for the acquisition of direct one‐bond heteronuclear correlations. The RDSQC (Randomly optimized Direct correlation Single Quantum Coherence) experiment utilizes an optimization based on the randomly ordered sampling of a range of couplings. The random order of the l/(2*(1JCHmin)) delays removes the signal dependency on a single type of apodization, thus eliminating a significant portion of the F1 artifacts induced in the accordion‐optimized ADSQC experiment. Compared to the statically optimized GHSQC, the randomly optimized data maintains the desired signal intensity in most cases, with a small loss for the weakly coupled proton‐carbon pairs and significant gains for the more strongly coupled pairs. Compared to the accordion‐optimized ADSQC data, the randomly optimized data afforded similar signal‐to‐noise without the F1 modulated artifacts simplifying spectral interpretation.
A simple one pot synthesis of condensed 1,2,4‐triazines by using the tandem aN‐SNipso and SNH‐SNipsa reactions
Authors: Chupakhin Oleg N. , Rusinov Gennady L. , Beresnev Dmitry G. , Charushin Valery N. , Neunhoeffer Hans 
Published: March 2009

AbstractA new synthetic approach to condensed 1,2,4‐triazines based on using the tandem AN‐SNipso and SNH‐SNipso reactions has been developed. 5‐Methoxy‐3‐penyl‐1,2,4‐triazine and its N1‐methyl quaternary salt were found to react with C,N‐, C,O‐ and N,N'‐bifunctional nucleophiles (m‐phenylenediamine, resor‐cinol, semicarbazide and ureas) into triazacarbazoles, benzofuro[2,3‐e][1,2,4]‐triazines, and 6‐azapurine derivatives. In all cases nucleophiles attack first the unsubstituted C‐6 carbon of the triazine ring, while the final stage is replacement of the methoxy group affording cyclization products.
Pyridazines 93. an unexpected reaction behaviour of 3‐aminopyridazine towards 2‐methylphenylisocyanate
Authors: Heinisch Gottfried , Hetzenauer Alfred , Matuszczak Barbara , Rakowitz Dietmar , Mereiter Kurt 
Published: March 2009

AbstractReaction of 3‐aminopyridazine (1) with 2‐mefhylphenylisocyante (4) affords not only the desired urea derivative (5) but also an unexpected side‐product (6), which could be identified as the corresponding biuret derivative by means of elemental and spectroscopic data as well as crystal structure determination.
Studies with enaminones: reactivity of 1,5‐disubstituted‐1,4‐pentadien‐3‐ones toward electrophilic reagents. a novel route to azolylazines, benzofuranals, pyranones
Authors: Al‐Mousawi Saleh , El‐Sherbiny Seham , John Elizabeth , Abdel‐Khalik Mervat Mohammed , Elnagdi Mohammed Hilmy 
Published: March 2009

AbstractSeveral new enaminodienones prepared from substituted acetone and dimethylformamide dimethylacetal were used as precursors for synthesis of pyridines, pyranones and benzofurans.
About 1‐triphenylmethyl‐3‐tert‐butylaziridinone and some of its reactions
Authors: Lengyel István , Cesare Victor , Karram Halina , Taldone Tony 
Published: March 2009

AbstractA high‐yield synthesis of 1‐triphenylmethyl‐3‐tert‐butylaziridinone (4), its physical and spectral properties, the limits of its thermal stability, and reactions with methanol, benzylamine and sodium methoxide in methanol are described.
Synthesis and isolation of nitro‐bT‐carbolines obtained by nitration of commercial β‐carboline alkaloids
Authors: Ponce María A. , Erra‐Balsells Rosa 
Published: March 2009

AbstractNitration of commercial full aromatic β‐carboline alkaloids nor‐harmane (1), harmane (2), harmine (3), harmol (4), and the 7‐acetylated derivative of harmol (5) is described. Advantages and disadvantages of different nitration reagents which involve acidic conditions (HNO3/H+) and neutral conditions (Cu(NO3)2; ceric ammonium nitrate) are discussed. A complete 1H and 13C‐nmr characterization including ms and also uv absorption spectra in neutral and acid media is presented. A detailed ei‐ms and ld‐tof‐ms study is enclosed because the nitro‐β‐carbolines constitute a new family of β‐carboline‐like chromophores with potential use as matrix in uv‐maldi‐tof‐ms.
Synthesis and isolation of bromo‐β‐carbolines obtained by bromination of β‐carboline alkaloids
Authors: Ponce María A. , Erra‐Balsells Rosa 
Published: March 2009

Abstractβ‐Carbolines (1–5) undergo electrophilic aromatic substitution with N‐bromosuccinimide under different experimental conditions. Although 6‐bromo‐nor‐harmane (la) obtained by bromination of nor‐harmane (1) was isolated and fully characterized sometime ago, the other bromoderivatives of nor‐harmane (1b‐1e) and harmane (2a‐2e) were partially described as part of the reaction mixtures. The preparation and subsequent isolation, purification and full characterization of 1b, 1c, 1d, 1e, 2a, 2b, 2c, 2d, 2e are reported (mp, Rf, 1H‐nmr, 13C‐nmr and ms) together with the preparation, isolation and charaterization, for the first time, of the bromoderivatives obtained from harmine (3a‐3e), harmol (4a, 4b) and 7‐acetylharmol (5a‐5c). As brominating reagent N‐bromosuccinimide and N‐bromosuccinimide‐silica gel in dichloromethane and in chloroform as well as the β‐carboline ‐ N‐bomosuccinimide solid mixture have been used and their uses have been compared. Semiempirical AMI and PM3 calculations have been performed in order to predict reactivity in terms of the energies of HOMO, HOMO‐LUMO difference and in terms of the charge density of β‐carbolines (1–5) and bromo‐β‐carbolines (1a‐1e, 2a‐2e, 3a‐3e, 4a, 4b, 5a, 5b and 5c) (Scheme 1). Theoretical and experimental results are discussed briefly.
Studies on the chemical transformations of rotenoids. 6 Synthesis and antitumor‐promoting activity of benzofuro[2,3‐d]pyridazines fused with 1,2,4‐triazole, 1,2,4‐triazine and 1,2,4‐triazepine
Authors: Nagai Shin‐Ichi , Takemoto Satoshi , Ueda Taisei , Mizutani Kanako , Uozumi Yasuhiro , Tokuda Harukuni 
Published: March 2009

Abstract[1]Benzofuro[2,3‐d]pyridazines fused with 1,2,4‐triazole (6 and 7), 1,2,4‐triazine (8–10) and 1,2,4‐tri‐azepine (12) were prepared by the ring closure of 4‐hydrazino‐[1]benzofuro[2,3‐d]pyridazine (5), derived from naturally occurring rotenone. Compounds (la and lb) exhibited significant inhibitory activity against 12‐O‐tetradecanoylphorbol 13‐acetate (TPA)‐induced Epstein‐Barr virus early antigen (EBA‐EA) activation in Raji cells. In contrast, the fused [1]benzofuro[2,3‐d]pyridazines except 6c and 8 were quite inactive.
1,6‐ and 1,7‐naphthyridines III. 13C‐NMR analysis of some hydroxy derivatives
Authors: Blanco M. Mercedes , Buldain Graciela , Schapira Celia B. , Perillo Isabel 
Published: March 2009

AbstractThe 13C‐NMR spectra of some 1,6‐naphthyridines 2 and 1,7‐naphthyridines 3, as well as those of N‐methyl derivatives 4 and 5, were recorded and analyzed. Results in dimethyl‐d6 sulfoxide and deuteriochlo‐roform provide useful data on intra and intermolecular hydrogen bonds.
Syntheses of substituted pyrrolo[2,3‐d]imidazole‐5‐carboxylates and substitued pyrrolo[3,2‐d]imidazole‐5‐carboxylates
Authors: Shafiee A. , Mojarrad J. Shahbazi , Jalili M. A. , Adhami H. R. , Hadizadeh F. 
Published: March 2009

AbstractStarting from readily available p‐substituted‐benzylamines a series of ethyl 2‐alkylthio‐1‐substituted‐ben‐zylpyrrolo[2,3‐d]imidazole‐5‐carboxylates was prepared. In addition, starting from 2‐alkyl‐4(or 5)‐formylimidazoles and methyl 4′‐bromomethylbiphenyl‐2‐carboxylate a series of methyl substituted‐pyrrolo[2,3‐d]imidazole‐5‐carboxylates and methyl substituted‐pyrrolo[3,2‐d]imidazole‐5‐carboxylates was prepared.
Identification of degradants of a complex alkaloid using NMR cryoprobe technology and ACD/structure elucidator
Authors: Martin Gary E. , Hadden Chad E. , Russell David J. , Kaluzny Brian D. , Guido Jane E. , Duholke Wayne K. , Stiemsma Bruce A. , Thamann Thomas J. , Crouch Ronald C. , Blinov Kirill , Elyashberg Mikhail , Martirosian Eduard R. , Molodtsov Sergey G. , Williams Antony J. , Schiff Paul L. 
Published: March 2009

AbstractIdentification of degradants of pharmaceuticals is a necessary challenge of the drug development process following the subjection of candidate molecules to a variety of physico‐chemical stresses. It would be desirable to be able to conduct such studies on a minimal amount of material. As a prototypical study, the isolation and identification of degradants of a sample of the complex indoloquinoline alkaloid, cryptospirolepine, was undertaken after prolonged storage in DMSO solution using a combination of cryogenic NMR probe technology and CASE (Computer‐Assisted Structure Elucidation) programs. None of the starting alkaloid remained after storage; a chromatogram of the DMSO solution demonstrated the presence of >25 components in the mixture. The two most abundant degradation products were identified as the known alkaloid cryptolepinone (∼35%) and an unprecedented rearrangement product, DP‐2, (∼16%).
Seco‐isopowellaminone: A new heterocycle from nornarwedine
Authors: Hirnschall Manfred , Froehlich Johannes , Jordis Ulrich , Mereiter Kurt 
Published: March 2009

AbstractIt is known that Nornarwedine‐type molecules can be converted into crinine‐type compounds by a reverse Michael‐ / Michael addition. Narwedine and bromonarwedine yield, as confirmed by X‐ray structure determination, the known seco‐powellaminone as well as the novel seco‐isopowellaminone.
Novel fluorescent 2‐(2‐aminofluorophenyl)benzoxazoles: Syntheses and photophysical properties
Authors: Tanaka Kiyoshi , Komiya Tomohiro 
Published: March 2009

Abstract2‐(2‐Amino‐3,4,5,6‐tetrafluorophenyl)benzoxazole (2) absorbs in long wavelength band (λabsmax = 346 nm in methanol) and in the normal wavelength band (λabsmax = 285.5 nm), and emits blue fluorescence. The emission intensity is highly affected by the solvent polarity and is large in a polar solvent such as methanol. 2‐(2‐Pentafluorobenzamido‐3,4,5,6‐ tetrafluorophenyl)benzoxazole (5) emits green fluorescence along with the short wavelength emission around 380 nm and their relative intensity depends on the solvent polarity. Green fluorescence is enhanced in nonpolar solvents such as chloroform and toluene, resulting in the considerably large Stokes shift.
Synthesis of 4‐alkyl‐1,2‐diphenyl‐3,5‐dioxopyrazolidines possessing aryl methylsulfonyl and sulfonamide pharmacophores for evaluation as selective cyclooxygenase‐2 (COX‐2) inhibitors
Authors: Rahim M. Abdur , Rao P. N. Praveen , Knaus Edward E. 
Published: March 2009

AbstractA group of 1,2‐diphenyl‐3,5‐dioxopyrazolidines possessing a methylsulfonyl (11) or sulfonamide (15) substituent at the para position of the N1‐phenyl ring, in conjunction with a hydrogen, methyl or fluoro sub‐stituent at the para position of the N2‐phenyl ring, and a C‐4 n‐butyl, methyl or spiro‐cyclopropyl substituent were synthesized for evaluation as potential cyclooxygenase‐2 (COX‐2) selective inhibitor antiinflammatory agents. The title compounds 11 and 15 were synthesized using a four‐step and a three‐step reaction sequence, respectively. Thus, the acetic acid promoted condensation of a nitrosobenzene 5 with an aniline derivative (6, 12) gave the corresponding azobenzene product (8, 13) which was reduced with zinc dust in the presence of ammonium chloride to yield the corresponding hydrazobenzene (9, 14). Base‐catalyzed condensation of 9 and 14 with a malonyl dichloride (10) afforded the target 3,5‐dioxopyrazolidine product (11,15). 4‐n‐Butyl‐1‐(4‐methylsulfonylphenyl)‐2‐phenyl‐3,5‐dioxopyrazolidine (11a) was a selective COX‐1 inhibitor (COX‐1 IC50 = 8.48 μM). In contrast, 4‐n‐butyl‐1‐(4‐methylsulfonylphenyl)‐2‐(4‐tolyl)‐3,5‐dioxopyrazolidine (11b, COX‐2 IC50 = 11.45 μM) and 4‐n‐butyl‐1‐(4‐methylsulfonylphenyl)‐2‐(4‐fluorophenyl)‐3,5‐dioxopyrazoli‐dine (11c, COX‐2 IC50 = 9.86 μM) were about 46‐fold and 20‐fold less selective COX‐2 inhibitors respectively, relative to the reference drug celecoxib.
Synthesis of indeno[2,1‐a]pyrrolo[3,4‐c]carbazole lactam regioisomers using ethyl cis‐β‐cyanoacrylate as a dienophile and lactam precursor
Authors: Hudkins Robert L. , Ho Park Chung 
Published: March 2009

AbstractReported here is the synthesis and characterization of the indenopyrrolocarbazole ring system utilizing a Diels‐Alder reaction with 2‐indenylindole and maleimide. Clemmensen reduction of imide 10 furnished the 5‐oxo (16) and 7‐oxo (17) lactam regioisomers. A new regiospecific route to 5‐oxo 16 was developed using ethyl cis‐β‐cyanoacrylate as the dienophile. The regio and stereochemical characterization of the cycloadducts was confirmed by X‐ray crystallography.
Syntheses and properties of benzodipyrrinones
Authors: Boiadjiev Stefan E. , Lightner David A. 
Published: March 2009

Abstract2,3‐Benzannelated dipyrrinone analogs (1 and 2) of xanthobilirubic acid (3) are prepared by base‐catalyzed condensation of isoindolinone (5) and indolin‐2‐one (6) respectively, with methyl 3‐(2‐formyl‐3,5‐dimethyl‐1H‐pyrrol‐4‐yl)propanoate (4). Nuclear Overhauser effect H‐nmr studies indicate that both 1 and 2 adopt preferentially a syn‐Z configuration. The former forms a hydrogen‐bonded homodimer in nonpolar solvents; the latter is intramolecularly hydrogen bonded.
New reactions of N‐T‐butyl‐N‐benzoylhydrazine with triphosgene
Authors: Qing‐Min Wang , Jun‐Ran Cheng , Run‐Qiu Huang 
Published: March 2009

AbstractN‐tert‐Butyl‐N‐benzoylhydrazine was prepared in a new and convenient procedure with good yield. Triphosgene underwent reaction with three equivalents of N‐t‐butyl‐N‐benzoylhydrazine using six equivalents of triethylamine as a base to yield the cyclic tetramer of N‐t‐butyl‐N‐isocyanatobenzoylamide. Treatment of triphosgene with three equivalents of N‐t‐butyl‐N‐benzoylhydrazine either in the presence of three equivalents of triethylamine or in the absence of triethylamine afforded the cyclic pentamer of iso‐cyanate, from which tert‐butyl is eliminated.
Oxidative cyclization of n‐methyl‐ and n‐benzoylpyridylthioureas. Preparation of new thiazolo[4,5‐b] and [5,4‐b] pyridine derivatives
Authors: Jouve Karine , Bergman Jan 
Published: March 2009

AbstractCyclization of N‐methyl‐ and N‐benzoylpyridylthioureas, prepared from the corresponding aminopy‐ridines, has been realized using various conditions. With bromine in acetic acid or potassium ferricyanide, the cyclization occurred on the nitrogen of the pyridine ring and pyridinium salts or 1,2,4‐fhiadiazolo[2,3‐a]pyridylidene systems were obtained. On the other hand, treatment of the thioureas with sodium methoxide in N‐methylpyrrolidinone (NMP) led to formation of fhiazolo[4,5‐b] and [5,4‐b]pyridines, which are interesting targets for biological evaluation.
Synthesis and unusual stability of pyridine and n‐methyl pyridinium 1,3‐dioxolanes
Authors: Hobson Stephen T. , Boecker Joseph D. , Gifford James H. , Nohe Tara L. , Wierks Carl H. 
Published: March 2009

AbstractDifferentially substituted bridged pyridinium oximes are necessary in research on antidotes for organophosphate poisoning. A solid‐phase synthesis would improve the yield and ease of purification of these compounds. To predict the lability of the linker in the final step of our proposed synthesis, we synthesized a series of pyridine and N‐methyl pyridinium acetals. These compounds proved to be resistant to acid catalyzed hydrolysis. This stability may be useful for synthetic manipulation of pyridine aldehydes.
Synthesis of homochiral 2‐C‐trifluoromethyl D‐and L‐ribose via trifluoromethylation of pentopyranosid‐2‐uloses
Authors: Eilitz Uwe , Böttcher Christoph , Hennig Lothar , Burger Klaus , Haas Alois , Gockel Simone , Sieler Joachim 
Published: March 2009

AbstractEfficient syntheses of 2‐C‐trifluoromethyl D‐ and L‐ribose and some O‐glycosides via trifluoromethylation of D‐ and L‐3,4‐O‐isopropylidene‐β‐erythro‐pentopyranosid‐2‐ulose with Ruppert's reagent are described.
Synthesis of novel 2‐amino‐1,3‐thiazole‐5‐carboxylates utilising ultrasonic and thermally mediated aminolysis
Authors: Baker Luke A. , Williams Craig M. 
Published: March 2009

AbstractNovel 2‐amino‐1,3‐thiazole‐5‐carboxylates have been synthesised in high yield by unprecedented ultrasonic and thermally mediated nucleophilic displacement of bromide from ethyl 2‐bromo‐1,3‐thiazole‐5‐car‐boxylate by primary, secondary and aryl amines.
An anomalous course of the reduction of 2‐(3‐oxo‐3,4‐dihydro‐quinoxalin‐2‐yl)benzene diazonium salt. Synthesis of a new quinoxalino[1,2‐c][1,2,3]benzotriazine system
Authors: Wiedermannová Iveta , Slouka Jan , Humpa Otakar , Lemr Karel 
Published: March 2009

AbstractBy diazotization of 3‐(2‐aminophenyl)quinoxaline‐2(lH)‐one la and 3‐(2‐aminophenyl)‐6,7‐dimethylquinoxaline‐2(lH)‐one 1b followed by the reaction with sodium sulphite new quinoxalino[1,2‐c]‐[1,2,3]benzotriazins 4a and 4b were prepared, respectively.
Structural characterization of a degradation product of tin ethyl etiopurpurin (SnET2): Comparison of the long‐range heteronuclear correlations detected using conventional GHMBC and IMPEACH‐MBC in conjunction with submicro NMR probe technology
Authors: Hadden Chad E. , Duholke Wayne K. , Kaluzny Brian D. , Sanders Phillip E. , Thamann Thomas J. , Martin Gary E. , Rosenqvist Kenneth , Robinson Byron C. , Masuno Mako N. 
Published: March 2009

AbstractDuring the terminal heat sterilization of the lipid emulsion final dose formulation of the photodynamic therapeutic (PDT) agent tin ethyl etiopurpurin (SnET2), a new degradant was observed at very low levels. The degradant, which was prone to photo‐instability, was isolated by preparative chromatography and subsequently characterized by mass spectrometry and NMR methods. Reproducible parent ion clusters were only observable via negative ion APCI methods. Because of the limited isolate sample, NMR characterization was done using 1.7 mm SMIDG (SubMicro Inverse‐Detection Gradient) NMR probe technology in conjunction with the accordion‐optimized IMPEACH‐MBC long‐range heteronuclear shift correlation experiment. The “static” 8 Hz optimization of the GHMBC experiment failed to allow the observation of a number of long‐range correlations that were of critical importance to the determination of the structure of the impurity. In contrast, all of the correlations required to assemble the structure were obtained from an IMPEACH‐MBC experiment optimized for long‐range heteronuclear couplings in the range from 2–10 Hz.
Syntheses of [1,2,3]selenadiazolo[4,5‐e]benzofuran or benzothiophene, [1,2,3]thiadiazolo[4,5‐e]benzofuran or benzothiophene, and 2‐benzofuranyl‐1,3,4‐oxodiazole derivatives
Authors: Shekarchi M. , Ellahiyan F. , Akbarzadeh T. , Shafiee A. 
Published: March 2009

AbstractDehydrogenation of ethyl 3‐methyl‐4‐oxo‐4,5,6,7‐tetrahydrobenzofuran‐2‐carboxylate 1 with 2,2′‐azobi‐sisobutyronitrile and N‐bromosuccinimide gave ethyl 4‐hydroxy‐3‐methylbenzofuran‐2‐carboxylate 3. Reaction of compounds 3–4 with hydrazine hydrate afforded the corresponding hydrazides 5a‐b. The reaction of 5a‐b with aldehydes yielded substituted hydrazones 6a‐l. Compounds 7a‐d were prepared from compounds 6a‐d and bromine in acetic acid. Lead tetraacetate oxidation of compounds 6e‐l afforded substituted oxadiazoles 8e‐l. Selenium dioxide oxidation of 4‐oxo‐4,5,6,7‐tetrahydrobenzofuran semicarbazones 9, 14a and 4‐oxo‐4,5,6,7‐tetrahydrobenzothiophene 14b gave the tricyclic 1,2,3‐selenadiazoles 10, 15a and 15b respectively. Reaction of semicarbazones 9, 14a and 14b with thionyl chloride afforded the corresponding 1,2,3‐thiadiazoles 12, 16a and 16b respectively.
3‐(phenylhydrazono)‐indan‐1‐one and 2‐dimethylaminomethylene‐3‐(phenylhydrazono)‐indan‐1‐one as useful synthons for the construction of new heterocyclic systems
Authors: Abu Elmaati Tarek M. , Said Samy B. , Abu Elenein Nahla S. , Khodeir Nabiel M. , Sofan Mamdouh M. 
Published: March 2009

AbstractThe hydrazone 1 reacts with DMFDMA to give 2‐dimethylaminomethylene‐3‐(phenylhydrazono)‐indan‐1‐one (2) which reacts with hydrazine hydrate and the pyrazole derivative 4 to afford the indenopyrazole derivatives 3 and the indenofluorene 5 respectively. The reaction of 2 with the active methylene compounds, mainly malononitrile, cyanoacetamide and malononitrile dimer was investigated and found to proceed successfully to yield the indenopyran 7, indenpyridine 8b and trinitrile 9 respectively. Compound 2 reacted with lH‐benzimidazole‐2‐acetonitrile 10 to give to the diazaindenofluorene derivative 11. Also, 2 reacted with ω‐cyano compounds 12a,b to afford the indenopyran 14. On the other hand the hydrazone 1 was allowed to react with the enaminones 15, 18 and 21 affording the diazabenzoazulene derivatives 17, 20 and the indeno[1,2‐b]pyridin 23, respectively.
Unusual fragmentation of fulvene endoperoxides with phenyliodosyl bis(trifluoroacetate) (PIFA)
Authors: Özer Galip , Saraçoǧlu Nurullah , Balci Metin 
Published: March 2009

AbstractReaction of unsaturated fulvene endoperoxides with dimethyl 1,2,4,5‐tetrazine‐3,6‐dicarboxylate gave saturated fulvene endoperoxides containing the 1,2‐dihydropyridazine ring. Treatment of dihydropyridazine endoperoxides with water followed by phenyliodosyl bis(trifluoroacetate) oxidation provided acrylic acid derivatives and dimethyl pyridazine‐3,6‐dicarboxylate.
Synthesis of chlorophyll‐a skeleton homologs using grignard reaction with methyl pyropheophorbide‐a
Authors: Wang Jin‐Jun , Shim Young Key , Jiang Gui‐Ji , Imafuku Kimiaki 
Published: March 2009

AbstractFrom methyl pyropheophorbide‐a (MPPa) (1), methyl 2‐formylmethyl‐2‐devinyl‐9‐ethylenedioxy‐9‐deoxopyropheophorbide‐a (2) and methyl 3‐acetyl‐9‐ethylenedioxy‐2‐devinyl‐9‐deoxopyropheophorbide‐a (3) were prepared. The Grignard reactions of 2 and 3 were performed using cycloalkyl magnesium bromides to afford cycloalkyl‐substituted sec‐alcohol 4 and tert‐alcohols 9a‐c, respectively. By the deprotection of the ethylenedioxy group, these alcohols were respectively converted to exocyclic ketones 5 and 10a‐c, which were dehydrated to give chlorins 6 and 11a‐c having an alkenyl function at the 2‐position. On the other hand, the oxidation and deprotection of the alcohol 4 gave a diketo chlorin 8.
Synthesis and biological activities of 2‐alkylthio‐5‐furylmethylidene‐4H‐imidazolin‐4‐ones
Authors: Yang Feng‐Ling , Liu Zhao‐Jie , Huang Xiao‐Bo , Ding Ming‐Wu 
Published: March 2009

AbstractNovel 2‐alkylthio‐5‐furylmethylidene‐4H‐imidazolin‐4‐ones 4 have been synthesized via tandem aza‐ Wittig reaction. The structures were determined by ir, nmr, mass spectroscopy, and elemental analysis. They were screened for fungicidal activities against Fusarium oxysporium, Botryosphaeria berengeriana and Rhizoctonia solani, and growth inhibition of Barnyard grass and Cole root and stalk. A few of them possess significant biological activities.
A convenient synthesis of novel pyrido(1′,2′:1,2)imidazo[5,4‐d]‐1,2,3‐triazinones from imidazo[1,2‐a]pyridines
Authors: Zamora Héctor Salgado , Rizo Benito , Campos Elena , Jiménez Rogelio , Reyes Alicia 
Published: March 2009

AbstractThe imidazo[1,2‐a]pyridine system was investigated as a synthon for the building of very attractive fused triazines, a planar, angular tri‐heterocycle with potential biological activity. Thus ethyl 3‐nitroimidazo[1,2‐a]pyridine‐2‐carboxylate was treated with ammonia or with an excess of primary amines to generate the corresponding substituted nitro carboxamidoimidazopyridines. The nitro substituent in the latter products, was reduced to yield 3‐amino‐2‐carboxamidoimidazo[1,2‐a]pyridine derivatives, which in turn were treated with nitrous acid to furnish 1‐oxo‐2‐substituted pyrido(1′,2′:1,2)imidazo[5,4‐d]‐1,2,3‐triazines.
Synthesis of new 2,3‐dihydrofuran‐3‐one derivative and its reactions with some primary amines
Authors: Üngören Ş. H. , Saçmaci M. , Akçamur Y. , Arici C. , Ülkü D. 
Published: March 2009

AbstractThe Wittig reaction of 2,3‐dihydro‐4‐(4‐methoxybenzoyl)‐5‐(4‐methoxyphenyl)‐furan‐2,3‐dione (1) with methyl (triphenylphosphoranylidene)acetate (2) stereo‐ and regioselectively afforded methyl (Z)‐[2,3‐dihydro‐4‐(4‐methoxybenzoyl)‐5‐(4‐methoxyphenyl)‐3‐oxofuran‐2‐ylidene]acetate (3) in good yield. The reactions of 3 with primary amines (4a‐k) gave corresponding 1‐substituted 2,3‐dihydro‐1Hpyrrol‐3‐ones (5a‐k).