bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative synthesis and NMR characterization of perhydro‐1,3,5‐tris(alkylpolyalkoxyl)‐S‐triazines
Authors: Wolak Thomas J. , Wollenberg Kurt F. , Adams Paul E. 
Published: March 2009

AbstractUnhindered polyalkoxylated primary amines, upon treatment with an equimolar equivalent of formalde hyde, cyclized quantitatively to afford perhydro‐1,3,5‐s‐triazines. This sereis of derivatives, based upon primary amine terminated poly(propylene and butylene oxides), possessed a molecular weight range of 1,900–5,800. Structure confirmation was accomplished by gel permeation chromatography and 2D nmr spectroscopy methods.
Synthesis of pyrrolo[2,1‐a]phthalazines by 1,3‐dipolar cycloaddition of phthalazinium N‐ylides with alkenes in the presence of tetrakis‐pyridine cobalt (II) dichromate
Authors: Zhou Jian , Hu Yuefei , Hu Hongwen 
Published: March 2009

AbstractWe describe here, for the first time, that 1‐cyano‐3‐benzoyl‐1,2,3,10b‐tetrahydropyrrolo[2,1‐a]phthalazine (8), prepared by 1,3‐dipolar cycloaddition of 2‐phenacyl phthalazinium bromide (6a) with acrylonitrile (7a), can be aromatized by tetrakis‐pyridine cobalt (II) dichromate (TPCD) to give 1‐cyano‐3‐benzoylpyrrolo[2,1‐α]phthalazine (9a) in good yield. Furthermore, a general and convenient one‐pot procedure for preparation of pyrrolo[2,1‐α]phthalazines (9a‐p) was developed by 1,3‐dipolar cycloaddition of phthala zinium N‐ylides (6a‐c) with alkenes (7a‐g) in the presence of TPCD.
Syntheses of new unsymmetrically dodecakis(trifluoroethoxy)‐substituted metallophthalocyanines by a palladium‐catalyzed cross‐coupling reaction
Authors: Tian Minquan , Wada Tatsuo , Sasabe Hiroyuki 
Published: March 2009

AbstractNovel unsymmetrical vanadyl and zinc dodecakis(2,2,2‐trifluoroethoxy)phthalocyaninates with an iodo group were synthesized by a statistical condensation route. The palladium‐catalyzed coupling reaction between such monoiodinated metallophthalocyanines and terminal acetylenic derivatives gave various new unsymmetrically dodecakis(2,2,2‐trifluoroethoxy)‐substituted metallophthalocyanines with extended exocyclic π‐conjugation. Unsymmetrical zinc dodecakis(2,2,2‐trifluoroethoxy)phthalocyaninate with a nitro group was also prepared for comparison. All the target phthalocyanines were separated by common col umn chromatography and characterized by elemental analysis, ir and 1H‐nmr, uv‐visible and fast‐atombombardment mass spectroscopy.
A new efficient synthesis of 3‐(hydroxymethyl)‐4H‐chromen‐4‐ones
Authors: Bolós Jordi , Loscertales Teresa , Nieto Joan , Sacristán Aurelio , Ortiz José A. 
Published: March 2009

AbstractAn efficient and versatile synthesis of variously substituted 3‐(hydroxymethyl)‐4H‐chromen‐4‐ones is reported. The compounds are prepared by hydroxymethylation of the precursor 2‐hydroxy‐4‐chromanones followed by acid dehydration.
A new synthesis of N‐alkyl pyrazolidine‐3,5‐diones and tetrahydropyridazine‐3,6‐diones
Authors: Le Bourdonnec Bertrand , Meulon Emmanuelle , Yous Saïd , Houssin Raymond , Hénichart Jean‐Pierre 
Published: March 2009

AbstractN‐alkyl pyrazolidine‐3,5‐diones and tetrahydropyridazine‐3,6‐diones have been synthesized by a new method in a three‐step sequence from dialkyl malonates or succinates respectively.
Ring transformations of heterocyclic compounds. XIX. Spiro[dihydropyridine‐indolines] novel heterocycles with two spiro‐condensed N‐containing subunits easy accessible by 1,3‐oxazinium ring transformation
Authors: Zimmermann Thomas , Abram Ulrich 
Published: March 2009

AbstractThe synthesis of hitherto unknown 1‐benzoyl‐1′,3′,3′‐trimethyl‐4,6‐diphenylspiro[1,2‐dihydropyridine‐2,2′‐indolines] 5 from 2,4,6‐triphenyl‐1,3‐oxazinium tetrafluoroborate (1b) and 1,3,3‐trimethyl‐2‐methyleneindolines 2 (used as such or generated in situ from the corresponding 3H‐indolium salts 4) in the presence of triethylamine in anhydrous acetonitrile by a 3,6‐[C3N+C2] 1,3‐oxazinium ring transformation is reported. Structure elucidation is performed by an X‐ray structure determination of the spiro[dihydropyridine‐indoline] 5a. Spectroscopic data of the transformation products and their mode of formation are discussed.
Quinolone analogues 2. A facile synthesis of novel 3‐substituted 1‐alkyl‐4‐oxo‐1,4‐dihydropyridazino[3,4‐b]quinoxalines
Authors: Kurasawa Yoshihisa , Sakurai Kazunori , Kajiwara Shinnosuke , Harada Kazuho , Okamoto Yoshihisa , Kim Ho Sik 
Published: March 2009

AbstractThe reaction of the 2‐(1‐alkylhydrazino)‐6‐chloroquinoxaline 4‐oxides 1a,b with diethyl acetone‐dicarboxylate or 1,3‐cyclohexanedione gave ethyl 1‐alkyl‐7‐chloro‐3‐ethoxycarbonylmethylene‐1,5‐dihydropyridazino[3,4‐b]quinoxaline‐3‐carboxylates 5a,b or 6‐alkyl‐10‐chloro‐1‐oxo‐1,2,3,4,6,12‐hexahydroquinoxalino[2,3‐c]cinnolines 7a,b, respectively. Oxidation of compounds 5a,b with nitrous acid afforded the ethyl 1‐alkyl‐7‐chloro‐3‐ethoxycarbonylmethylene‐4‐hydroxy‐1,4‐dihydropyridazino‐[3,4‐b]quinoxaline‐4‐carboxylates 9a,b, whose reaction with base provided the ethyl 2‐(1‐alkyl‐7‐chloro‐4‐oxo‐1,4‐dihydropyridazino[3,4‐b]quinoxalin‐3‐yl)acetates 6a,b, respectively. On the other hand, oxidation of compounds 7a,b with N‐bromosuccinimide/water furnished the 4‐(1‐alkyl‐7‐chloro‐4‐oxo‐1,4‐dihydropyridazino[3,4‐b]quinoxalin‐3‐yl)butyric acids 8a,b, respectively. The reaction of compound 8a with hydroxylamine gave 4‐(7‐chloro‐4‐hydroxyimino‐1‐methyl‐1,4‐dihydropyridazino[3,4‐b]quinoxalin‐3‐yl)‐butyric acid 12.
Research on heterocyclic compounds. XLII. The vilsmeier reaction in the synthesis of imidazo[1,2‐a]pyrimidine derivatives
Authors: Laneri Sonia , Sacchi Antonia , Abignente Enrico 
Published: March 2009

AbstractThe Vilsmeier reaction on imidazo[1,2‐a]pyrimidine ring is reported. The 3‐formyl derivative obtained is oxidized to yield the corresponding carboxylic acid.
Synthesis and structural analysis of (E)‐2‐(2′‐nitrovinyl)indoles from the corresponding 2‐formylindole derivatives
Authors: Rodriguez J. Gonzalo , Lafuente Antonio , Garcïa‐Almaraz Pablo 
Published: March 2009

AbstractPreparation of 2‐formylindoles was carried out from the appropriate methylindole by oxidation with selenium dioxide and by Vilsmeier formylation. The 2‐(2′‐nitrovinyl)indoles have been obtained by condensa tion of 2‐formylindoles with nitroalkanes in the presence of ammonium chloride in good yields. In this reac tion, only the (E)‐isomer of the 2‐(2′‐nitrovinyl)indoles was observed by1H nmr and NOE experiments. Evidence for an extended conjugation through the double bond and the nitro group can be evaluate by the deshielding effect on the olefinic protons. Moreover, the non‐Beer's law behaviour in the uv‐visible spectra suggest the existence of some sort of complex for these compounds.
Ruthenium‐Catalyzed synthesis of quinolines from anilines and N‐allylic compounds by cascade amine exchange reaction‐heteroannulation
Authors: Cho Chan Sik , Ho Oh Byoung , Shim Sang Chul , Oh Dae Hee 
Published: March 2009

AbstractAnilines react with N‐allylic compounds such as triallylamine and N,N‐diallylaniline in dioxane in the presence of a catalytic amount of ruthenium(III) chloride hydrate and bis(diphenylphosphino)methane and tin(II) chloride dihydrate to afford the corresponding quinolines in high yields. Several other phosphorus ligands are also effective, but bis(diphenylphosphino)methane is the ligand of choice. A reaction pathway involving cascade amine exchange reaction‐heteroannulation is proposed for this catalytic process.
Synthesis of cyanine dyes derived from benzotellurazo‐15‐crown‐5
Authors: Ke Weijun , Luo Xuehong , Liu Xiufang , Xu Hansheng 
Published: March 2009

AbstractA series of crown ether cyanine dyes including crown ether styryl cyanine dyes, crown ether merocyanine dyes and crown ether squarylium cyanine dyes (unsymmetric and symmetric) derived from key intermediate 2‐methyl‐5,6(15‐crown‐5)benzotellurazole (1) were prepared.
Synthesis and reactions of 2‐hetero‐4H‐3,1‐benzoxazin‐4‐ones
Authors: Coppola Gary M. 
Published: March 2009

AbstractThe present review covers the synthesis and reactions of 2‐hetero‐4H‐3,1‐benzoxazin‐4‐ones which include oxygen, sulfur and nitrogen substituents. Literature coverage includes publications primarily from the mid 1960's to December 1999.
1H‐4,5,6,7‐tetrahydro‐1,3‐diazepines. Part I: Synthesis, spectral and chemical properties of 1,2‐diaryl derivatives
Authors: Hedrera Mónica E. , Perillo Isabel A. 
Published: March 2009

AbstractThe synthesis of several 1,2‐diaryl‐1H‐4,5,6,7‐tetrahydro‐1,3‐diazepines 1 by cyclization of N‐aryl‐N'‐benzoyltetramethylenediamines 2 is described. Two alternative synthetic routes to obtain precursors 2 are discussed, being that which employes pyrrolidine as starting material the most convenient. Nucleophilic attack of compounds 1 on methyl iodide affords 1,2‐diaryl‐1H‐4,5,6,7‐tetrahydro‐1,3‐diazepinium iodides 3. 1H‐nmr spectra of these compounds are unequivocally assigned by means of NOESY experiments, 1H‐nmr spectra of compounds 1 and 3 are analyzed and compared inter se and with those of compounds 1 run in the presence of trifluoroacetic acid‐d. Reduction of compounds 1 with borane leads regiospecifically to N‐aralkyl‐N'‐aryltetramethylenediamines 7.
New 2‐methylisothiazolones
Authors: Nádel Ágnes , Pálinkás János 
Published: March 2009

AbstractNew N,N'‐bis(alkoxycarbonyl)‐L‐cystine bis(methylamides) 4a, 4b and N,N'‐bis(benzyloxycarbonyl)‐L‐cystine bis(methylamide) 4c have been synthesized by mixed anhydride method from the essential amino acid L‐cystine 1 in good yield. These cystine bis(methylamides) 4a,b,c have been cyclized with sulfuryl chloride. New 2‐methyl‐4‐amino‐3‐isothiazolone and 5‐chloro‐2‐methyl‐4‐amino‐3‐isothiazolone hydrobromide salts 7, 8 have been obtained by deacylation of 2‐methyl‐4‐(benzyloxycarbonyl)amino‐3‐isothiazolone 5c and 5‐chloro‐2‐methyl‐4‐(benzyloxycarbonyl)amino‐3‐isothiazolone 6c with hydrogen bromide in acetic acid. The microbicidal effect of the new 2‐methy]‐3‐isothiazolones 5a,b,c; 6a,b,c; 7 and 8 compounds obtained by the above method has been investigated.
Synthesis of analogs of the ergot alkaloids
Authors: Strekowski Lucjan , Van Aken Koen , Gulevich Yuri 
Published: March 2009

AbstractA number of 3,4,5,6‐tetrahydro‐1H‐azepino[5,4,3‐cd]indole derivatives have been synthesized starting with methyl indole‐4‐carboxylate functionalized at the 3 position.
Synthesis of 5‐N‐glycosylaminopyrimidines. A new class of compounds with potential anti‐aids activity
Authors: López M. D. , Quijano M. L. , Sánchez A. , Nogueras M. 
Published: March 2009

AbstractReactions between 5,6‐diaminopyrimidines 1a‐c and pentoses 2a‐e yield 5‐N‐glycosylaminopyrirnidines or 7‐polyhydroxyalkylpteridines, depending on the presence or absence of acetic acid. The “in vitro” anti‐HIV activity of 6‐amino‐2‐methoxy‐3‐methyl‐5‐N‐D‐ribosylaminopyrimidin‐4(3H)‐one 3e, 6‐amino‐2‐methoxy‐3‐methyl‐5‐N‐β‐D‐xylopyranosylaminopyrimidin‐4(3H‐one 3f, and 6‐amino‐2‐methylthio‐5‐N‐β‐L‐xylopyranosylminopyrimidin‐4(3H)‐one 3k, appears to be promising.
Synthesis of tricyclic triazepinones related to nevirapine
Authors: Castellano Sabrina , Stefancich Giorgio , La Colla Paolo , Musiu Chiara 
Published: March 2009

AbstractTwo novel tricyclic triazepinones structurally related to the reverse transcriptase inhibitor nevirapine were prepared from N‐(2‐nitrophenyl)‐ and N‐(3‐nitro‐2‐pyridinyl)‐1H‐pyrrol‐1‐amine. The synthetic sequence includes alkylation, reduction of the nitro group, triphosgene reaction followed by intramolecular cyclization. Activity of the two compounds against the HIV‐1 multiplication in acutely infected cells is also reported.
Facile access to 6‐substituted 1,4,5,7‐tetrahydropyrrolo[3,4‐b]‐pyridines via hantzsch type dimethyl 4‐aryl‐2‐formyl‐6‐methyl‐1,4‐dihydropyridine‐3,5‐dicarboxylates
Authors: Chudík Milostav , Marchalín Štefan , Knesl Peter , Daich Adam , Decroix Bernard 
Published: March 2009

AbstractEfficient assembly of 6‐substituted 4‐aryl‐5‐oxo‐1,4,5,7‐tetrahydropyrrolo[3,4‐b]pyridines (7a‐f) is described according to a Hantzsch type reaction from formyl‐ester 4 by imination, borohydride reduction and intramolecular thermal amino‐ester cyclization. The starting compound 4 was prepared in three steps from the readily available formyl derivative 1, methyl 4,4‐dimethoxy‐3‐oxobutanoate and methyl 3‐aminocrotonate.
Heteroelectrocyclic reaction of 4‐azido‐3‐hydrazonoalkyl‐quinolines to 2‐arylaminopyrazolo[4,3‐c]quinolones
Authors: Hojas Gerhard , Fiala Werner , Stadlbauer Wolfgang 
Published: March 2009

Abstract4‐Azido‐3‐acylquinolones 4 obtained from 4‐hydroxy derivatives 1 via tosylates 3 or chlorides 5, reacted with arylhydrazines 6 to generate 4‐azido‐3‐hydrazonoalkylquinolines 7. Thermolysis of 7 gave ring closure products which were assigned to 2‐arylaminopyrazolo[4,3‐c]quinolones 10. The thermal decomposition conditions of the azides 4 and 7 were studied by differential scanning calorimetry (DSC).
A facile synthesis of 3H‐indolium perchlorates by one‐pot hydrazone formation/fischer indolization
Authors: Zimmermann Thomas 
Published: March 2009

AbstractN‐Substituted N‐phenylhydrazines 1, α‐branched ketones 2 and perchloric acid react in boiling ethanol to give via the in situ formed hydrazones 3 1,2,3,3‐tetrasubstituted 3H‐indolium perchlorates 4. The scope and limitations of this facile synthesis of 3H‐indolium derivatives which combines the hydrazone formation and the Fischer indolization to an one‐pot procedure are discussed.
Synthesis of nitrogen‐containing heterocycles 9. Preparation and carbon‐carbon bond cleavage of spiro[cycloalkane[1′,2′,4′]‐triazolo[1′,5′‐a][1′,3′,5′]triazine] derivatives and related compounds
Authors: Miyamoto Yoshiko 
Published: March 2009

AbstractDiaminomethylenehydrazones of cyclic ketones 1–5 reacted with ethyl N‐cyanoimidate (I) at room temperature or with bis(methylthio)methylenecyanamide (II) under brief heating to give directly the corresponding spiro[cycloalkane[1′,2′,4′]triazolo[1′,5′,‐a][1′,3′‐5′]triazine] derivatives 7–12 in moderate to high yields. Ring‐opening reaction of the spiro[cycloalkanetriazolotriazine] derivatives occurred at the cycloalkane moiety upon heating in solution to give 2‐alkyl‐5‐amino[1,2,4]triazolotriazines 13–16. Diaminomethylenehydrazones 17–19, of hindered acyclic ketones, gave 2‐methyl‐7‐methylthio[1,2,4]‐triazolo[1,5‐a][1,3,5]triazines 21–23 by the reaction with II as the main products with apparent loss of 2‐methylpropane from the potential precursor, 2‐tert‐butyl‐2‐methyl‐7‐methylthio[1,2,4]triazolo[1,5‐a]‐[1,3,5]triazines 20, in good yields. In general, bis(methylthio)methylenecyanamide II was found to be a favorable reagent to the one‐step synthesis of the spiro[cycloalkanetriazolotriazine] derivatives from the diaminomethylenehydrazones. The spectral data and structural assignments of the fused triazine products are discussed.
Methoxylation of 4,5‐Dichloro‐2‐methyl‐6‐nitropyridazin‐3‐one
Authors: Park Jung‐Won , Kim Jeum‐Jong , Kim Ho‐Kyun , Kang Young‐Jin , Lee Woo Song , Yoon Yong‐Jin 
Published: March 2009

AbstractThis paper presents the methoxylation of 4,5‐dichloro‐2‐methyl‐6‐nitropyridazin‐3‐one with potassium carbonate/methanol.
Synthesis of 4‐(2‐hydroxyphenyl)‐1‐phenyl‐1,2,4‐triazolidine‐3,5‐dione derivatives through cyclic transformations of 3‐(2‐phenylcarbazoyl)‐2(3H)‐benzoxazolone derivatives
Authors: Chau François , Milcent René 
Published: March 2009

AbstractFour 3‐(3‐benzylidene‐2‐phenylcarbazoyl)‐2(3H)‐benzoxazolone derivatives 3 have been synthesized from benzoxazolone derivatives 1 and benzaldehyde N‐chloroformylphenylhydrazone 2. By acid hydrolysis, these compounds yielded 3‐(2‐phenylcarbazoyl)‐2(3H)benzoxazolone derivatives 4 which were not isolated and were transformed via an intramolecular reaction into 4‐(2‐hydroxyphenyl)‐1‐phenyl‐1,2,4‐triazolidine‐3,5‐dione derivatives 5 in a good yield. Attempts to cyclize these compounds by intramolecular elimination of water into tricyclic compounds 6 with various dehydrating agents were unsuccessful.
Research on potentially bioactive aza and thiaza polycyclic compounds containing a bridgehead nitrogen atom. III. Synthesis and antimicrobial activity of some 1,4‐benzothiazines and pyrrolobenzothiazines
Authors: Armenise Domenico , Trapani Giuseppe , Arrivo Vittorio , Laraspata Elena , Morlacchi Flaviano 
Published: March 2009

AbstractCyclization reactions of N‐(2,2‐dialkoxyethyl)‐1,4‐benzothiazine lactams 2 and 1,4‐benzothiazine‐sulfones 10 lead to the corresponding pyrrolo[1,2,3‐de]‐1,4‐benzothiazines 4 and 12, respectively, by using the dioxane/p‐toluenesulfonic acid or polyphosphoric acid/chloroform systems. In contrast, in the same reaction conditions, 1,4‐benzothiazines 5a‐h do not provide the expected pyrrolobenzothiazines 7, and as for 5c‐h considerable amount of the 2‐amino‐phenyl‐sulfide 8 was obtained. The results of microbiological assays are reported.
A long‐range 15N‐NMR study of the oxazolidinone antibiotic zyvox® and the major thermal degradation products
Authors: Hadden C. E. , Bowman P. B. , Duholke W. H. , Guido J. E. , Kaluzny B. D. , Robins R. H. , Russell D. J. , Sims S. M. , Thamann T. J. , Martin G. E. 
Published: March 2009

AbstractThe structures of the major thermal degradation products of linezolid (Zyvox®, PNU‐100766) are reported. Following hydrolytic decarboxylation, the remaining oxazolidinone‐derived skeleton of the antibiotic underwent a variety of acetyl migrations prior to deacetylation. Three of the degradation products are structural isomers. Structural characterization of the degradants was accomplished via the concerted analysis of 2D NMR, mass spectrometric, and infrared data. Direct and long‐range 1H‐15N heteronuclear shift correlation experiments at natural abundance were performed on linezolid as well as each of the isolated products of the degradation cascade. 15N chemical shifts for linezolid and each of the degradants, as well as the observed long‐range 1H‐15N coupling pathways are reported.
New precursors for hexanitrohexaazaisowurtzitane (HNIW, CL‐20)
Authors: Chung Kyoo‐Hyun , Kil Hee‐Sup , Choi In‐Young , Chu Chan‐Kook , Lee Ik‐Mo 
Published: March 2009

AbstractTwo new polyacylhexaazaisowurtzitanes were synthesized. Pentaacetyl‐ or pentaacetylformylhexaazaisowurtzitane can be a precursor in the preparation of HNIW, recently developed highly energetic material.
An improved synthesis of pyrazolo[3,4‐b][1,5]benzoxazepine, ‐benzothiazepine and ‐benzodiazepine derivatives via a convenient one‐pot synthesis
Authors: Abd El Latif Fawi M. 
Published: March 2009

AbstractAn improved and simple method for the preparation of pyrazolo[3,4‐b][1,5]benzoxazepine, ‐benzothiazepine and ‐benzodiazepine derivatives was established by the reaction of 5‐chloro‐1‐phenylpyrazole‐4‐carbaldehydes, ethyl 3‐(5‐chloro‐1,3‐diphenylpyrazol‐4‐yl)‐2‐cyanoacrylate and 1,4‐diacetyl‐3‐methyl‐2‐pyrazolin‐5‐one with o‐aminophenol derivatives and o‐phenylendiamine.
Synthesis and central nervous system stimulant activity of camphor‐1,2,3‐triazine fused with diphenylcyclopropenone and camphor‐1,2,3‐triazine n‐oxides
Authors: Nagai Shin‐Ichi , Ueda Taisei 
Published: March 2009

AbstractReactions of camphor‐1,2,3‐triazine 1 with diphenylcyclopropenone 2 gave two cycloadducts; 6,9‐methanopyrazolo[1,2‐b][1,2,3]benzotriazinones 3–4. Oxidation of 1 with 3‐chloroperbenzoic acid gave 1‐oxide 5 as the major compound along with a trace of 1,2‐dioxide 6.
Syntheses and photophysical properties of some 4‐arylpyridinium salts
Authors: Kelley Charles J. , Ansu Kwabena , Budisusetyo Wiranto , Ghiorghis Alem , Qin Yuanxi , Kauffman Joel M. 
Published: March 2009

AbstractA number of 4‐arylpyridines, many methoxy substituted, were prepared by an efficient two‐step method involving aryl Grignard addition to 1‐methyl‐4‐piperidone and direct aromatization of the resulting 4‐aryl‐4‐piperidinols. The pyridines were N‐alkylated to give sulfonate salts desired for their fluorescent properties. Study of selected compounds as laser dyes revealed several structures to be efficient dyes lasing in the 530‐550 nm range. Two new diazaquaterphenyls were prepared and were quaternized. These salts exhibited intense fluorescence in the 420‐450 nm range, but would not lase. A phenolic azaterphenyl suitably substituted for excited state intramolecular proton transfer (ESIPT) did not fluoresce at all.
Thieno[2′,3′:5,6]azepino[2,1‐a]isoindolones from hydroxylactam‐alcohols via N‐acyliminium ion olefin cyclization
Authors: Pigeon Pascal , Othman Mohamed , Decroix Bernard 
Published: March 2009

AbstractA one pot synthesis of thienoazepinoisoindolones from the reaction of hydroxylactam‐alcohols, under acidic treatment, is described via an N‐acyliminium olefin cyclization.
Metalation and halogen‐metal exchange in the imidazo[1,2‐a]quinoxaline series
Authors: Parra Stéphanie , Vitse Olivier , Bénézech Véronique , Deleuze‐Masquéfa Carine , Subra Guy , Bompart Jacques , Escale Roger , Chapat Jean P. , Bonnet Pierre A. 
Published: March 2009

AbstractThe n‐butyllithium and lithium 2,2,6,6‐tetramethylpiperidide metalation and the halogen‐metal exchange of imidazo[1,2‐a]quinoxaline derivatives followed by quenching with various electrophiles were studied. The reaction conditions have been optimized and various C1 substituted imidazo[1,2‐a]quinoxalines were obtained in high yields.
Synthesis and reaction of 5,6,7,8‐tetrahydro‐4H‐oxazolo[4,5‐c]azepin‐4‐ones
Authors: Koh Young Kook , Bang Ki‐Hwan , Kim Hong‐Seok 
Published: March 2009

AbstractThe synthesis of 5,6,7,8‐tetrahydro‐4H‐oxazolo[4,5‐c]azepin‐4‐ones 5a,b and 1,3‐benzoxazol‐4‐amines 4a,b are described starting from 4,5,6,7‐tetrahydro‐1,3‐benzoxazol‐4‐ones. Thionation of 5a,b followed by alkylation with ethyl bromoacetate led to the corresponding S‐alkyl azepines 7a,b.
Synthesis of indole and indolenine derivatives starting from indoline‐2‐thiones
Authors: Nishio Takehiko , Saku Osamu , Yamamoto Hiroshi 
Published: March 2009

AbstractIndoline‐2‐thiones 1a‐b,d,f,h, which have at least one hydrogen at the 3‐position reacted with α‐halo ester 2a‐d, α‐halo ketones 2e‐f, and a‐bromoacetonitrile 2g to give 2‐alkylthioindole derivatives 3–11. In a similar manner treatment of 3,3‐disubstituted indoline‐2‐thiones 1c,e with α‐halo esters 2a,c,d and α‐halo ketone 2e gave 2‐alkylthioindolenines 12–16. Treatment of 1,3,3‐ trisubstituted indoline‐2‐thiones 1g,i with ethyl bromo‐acetate 2a resulted in recovery of starting materials. Desulfurization of indolenine 14 with triphenylphosphine gave 2‐alkylideneindoline 19.
Preparation of 1,6‐naphthyridine‐2,5(1H,6H)‐diones
Authors: Ohta Tetsuo , Fujisawa Hironori , Kawazome Mitsuru , Nakai Yasuto , Furukawa Isao 
Published: March 2009

AbstractNovel method for the synthesis of 3‐acyl‐1,6‐dialkyl‐7‐methyl‐1,6‐naphthyridine‐2,5(1H,6H)‐diones (2) was developed. The reaction of 2‐acyl‐1‐alkylamino‐1‐ethoxyethylenes (1) with acetyl chloride or β‐keto amide 3 with acetyl chloride in the presence of p‐toluenesulfonic acid gave 2 in moderate yield (14‐59% yield).