bluuebunny/crossref_metadata_2025_split huggingface dataset:
Michael addition of benzoylacetonitrile to chiral α‐cyanoacrylates derived from enantiomerically pure α‐hydroxyaldehydes: Synthesis of 3‐alkoxycarbonyl‐4‐alkyl‐2‐amino‐5‐cyano‐6‐phenyl‐4H‐pyrans
Authors: Jiménez Blanca , Martín Nazario , Martínez‐Grau Angeles , Seoane Carlos , Marco José L. 
Published: March 2009

AbstractWe describe the Michael addition of benzoylacetonitrile to α‐cyanoacrylates 4a‐c and 5a obtained from readily available chiral α‐hydroxyaldehydes 1a‐c. The resulting polyfunctionalized 4‐alkyl‐2‐amino‐4H‐pyrans 6a‐c, 7a have been obtained in good yield and moderate diastereoselectivity.
Reduction of indolo[2,3‐a]quinolizidines with baker's yeast
Authors: Farés F. A. , Virelizier H. , Jankowski K. , Gribble G. W. 
Published: March 2009

AbstractThe reduction of several indolo[2,3‐a]quinolizidines with Baker's yeast (Saccharomyces cerevisiae) affords novel reduction products resulting from reduction of the indole double bond, cleavage of the C‐D ring junction, or reduction of a lactam to a carbinol amine, as determined by high resolution mass spectrometry.
Cyclization of 3‐fluorophenol and 3,3‐dimethylacrylic acid: A structure correction
Authors: Shawcross Frances , Sard Howard 
Published: March 2009

AbstractReaction of 3‐fluorophenol and 3,3‐dimethylacrylic acid in methanesulfonic acid at 90° gives predominantly 5‐fluoro‐2,2‐dimethylchroman‐4‐one, not the 7‐fluoro isomer as reported [1].
Preparation of 7‐ethoxy‐3‐hydroxy‐6‐methoxy‐1‐methyl‐4‐nitroisoquinoline
Authors: Barton Donald L. , Fabian Arthur C. , Lam Margaret M. , Sterbenz Jeffrey T. 
Published: March 2009

AbstractThis paper reports the large scale preparation of 7‐ethoxy‐3‐hydroxy‐6‐methoxy‐1‐methyl‐4‐nitroiso‐quinoline (RWJ 19959,2) from an available starting material, 4‐ethoxy‐3‐methoxyphenylacetic acid (9). Previously 2 was prepared via a perchlorate salt which was found to decompose exothermically.
Aldol condensation of 6‐alkoxy‐2,2‐dimethylchroman‐4‐ones with substituted benzaldehydes using tetramethylorthosilicate and potassium fluoride
Authors: Chambers R. J. , Marfat A. 
Published: March 2009

AbstractThe aldol condensation of 6‐alkoxy‐2,2‐dimethylchromanones 1 or 2 with substituted benzaldehydes in the presence of tetramethylorthosilicate and potassium fluoride affords 6‐alkoxy‐3‐benzylidene‐2,2‐dimethylchromanones 5‐10 while other conventional methods were unsuccessful.
An example of a novel formation of an oxepin
Authors: Parlow John J. 
Published: March 2009

AbstractA novel formation of an oxepin, namely 9,10,11,12‐tetrafluoro‐5,6‐dihydrobenzo[b]naphth[2,1‐f]oxepin (5), starting from pentafluoroacetophenone and 1‐tetralone is described. Also, the same synthesis using 1‐indanone affords a very different ring system namely 1,2,3,4‐tetrafluoro‐5,11b‐dihydro‐7H‐benzo[c]fluoren‐7‐one (10). Both synthesis undergo an intramolecular nucleophilic substitution of an ortho‐fluorine. In one case, the oxygen displaces the fluorine to afford the oxepin 5 and the other a carbon is used as the nucleophile to give the polycyclic ring system 10.
Synthesis and anticonvulsant activity of 3H‐imidazo[4,5‐c]‐pyridazine, 1H‐imidazo[4,5‐d]pyridazine and 1H‐benzimidazole analogues of 9‐(2‐fluorobenzyl)‐6‐methylamino‐9H‐purine
Authors: Kelley James L. , Thompson James B. , Styles Virgil L. , Soroko Francis E. , Cooper Barrett R. 
Published: March 2009

AbstractThe 3H‐imidazo[4,5‐c]pyridazine, 1H‐imidazo[4,5‐d]pyridazine, and 1H‐benzimidazole analogues of the potent anticonvulsant purine 9‐(2‐fluorobenzyl)‐6‐methylamino‐9H‐purine (1, 78U79) were synthesized and tested for anticonvulsant activity. The 3H‐imidazo[4,5‐c]pyridazines 8 and 9 were prepared in five stages from 3,4,5‐trichloropyridazine (2). The 1H‐imidazolo[4,5‐d]pyridazine 15 was synthesized in four stages from 5‐[(benzyloxy)methyl]‐1,5‐dihydro‐4H‐imidazo[4,5‐d] pyridazin‐4‐one (10a). The benz‐imidazole analogues 18 and 20 were prepared from 2,6‐dinitroaniline in three stages. These compounds were one‐tenth or less as active as 1 in protecting rats against maximal electroshock‐induced seizures.
Synthesis of pyrrolo[3,4‐c]pyridazines
Authors: Poschenrieder Hermann , Stachel Hans‐Dietrich 
Published: March 2009

AbstractWe have prepared the pyrrolopyridazines 7a‐f starting from the diazo compounds 4. The synthesis involves a tandem condensation‐aza‐Wittig reaction or a combination of Wittig and aza‐Wittig reactions as key steps. Reaction of pyridazine 7d with diazomethane results in C‐methylation to yield 7g. Sodium borohydride reduces 7d to either the dihydropyridazine 12 or the hydroxylactam 13b depending of the reaction conditions.
Synthesis of 5‐(4‐substituted benzyl)‐2,4‐diaminoquinazolines as inhibitors of candida albicans dihydrofolate reductase
Authors: Jagdmann G. Erik , Chan Joseph H. , Styles Virgil L. , Tansik Robert L. , Boytos Christine M. , Rudolph Sharon K. 
Published: March 2009

AbstractSeveral 5‐(4‐substituted benzyl)‐2,4‐diaminoquinazolines were prepared as potentially selective inhibitors of Candida albicans dihydrofolate reductase. These compounds were synthesized by a novel route, which included as a key step the displacement of a fluoro group in 2,6‐difluorobenzonitrile by the anions of ethyl or methyl 4‐substituted phenylacetates. The resultant diarylacetates were saponified and decarboxylated to the 2‐fluoro‐6‐(4‐substituted phenyl)benzonitriles. Ring closure of these benzonitriles with guanidine carbonate gave the 5‐(4‐substituted benzyl)‐2,4‐diaminoquinazolines.
Synthesis and biological evaluation of ‐n[4‐(2‐trans‐[([2,6‐diamino‐4(3H)‐oxopyrimidin‐5‐yl]methyl)thio]cyclobutyl)benzoyl] ‐l‐glutamic acid a novel 5‐thiapyrimidinone inhibitor of dihydrofolate reductase
Authors: Varney Michael D. , Romines William H. , Boritzki Theodore , Margosiak Stephen A. , Bartlett Charlotte , Howland Eleanor J. 
Published: March 2009

AbstractThe synthesis and biological evaluation of N‐[4‐(2‐trans‐[([2,6‐diamino‐4(3H)‐oxopyrimidin‐5‐yl]methyl)thio]cyclobutyl)benzoyl]‐L‐glutamic acid (1) is reported. Compound 1 is a potent dihydrofolate reductase (DHFR) inhibitor (Kj = 12 nM) with excellent in vitro cell culture growth inhibition (L1210, IC50 = 29 nM). Protection experiments showed that the cell growth inhibitory activity was due to DHFR inhibition. The key step in the synthesis was the coupling of a cyclobutylmethylthiol with the 5‐bromo‐2,6‐diamino‐4‐oxopyrimidine 8.
The synthesis of benzofuroquinolines. X. Some benzofuro[3,2‐c]isoquinoline derivatives
Authors: Yamaguchi Seiji , Yoshida Mika , Miyajima Izumi , Araki Toshikatsu , Hirai Yoshiro 
Published: March 2009

AbstractCondensation of salicylonitrile with ethyl α‐bromo‐α‐(o‐ethoxycarbonylphenyl)acetate (4) effectively gave 5(6H)‐benzofuro[3,2‐c]isoquinolinone (2), which was converted to some 5‐substituted benzofuro‐[3,2‐c]isoquinoline derivatives 1a‐g.
Synthesis, Characterization, and crystallographic analysis of some benzoimidazole derivatives
Authors: Benvenuti Stefania , Severi Fabio , Vampa Gabriella , Malmusi Luca , Antolini Luciano 
Published: March 2009

AbstractA number of benzenesulfonyl derivatives of benzoimidazol‐2‐ylamine and 1‐methyl‐benzoimidazol‐2‐ylamine were synthesized, their synthesis reactions under different experimental conditions being monitored by hptlc. The crystal and molecular structures of N‐(1‐benzenesulfonyl‐1,3‐dihydrobenzoimidazol‐2‐ylidene)benzenesulfonamide (4) and N‐(1‐benzenesulfonyl‐3‐methyl‐1,3‐dihydro‐benzoimidazol‐2‐ylidene)‐benzenesulfonamide (7) were determined by X‐ray diffraction analysis. The structure of compound 4 is made up of two crystallographically independent molecules and that of compound 7 of one molecule. In both cases, the structure contains the imido form of the molecules. There are strong conjugative effects between the imido groups and the imidazolic rings. Weak intramolecular CH···O hydrogen bonding interactions could influence the molecular conformations.
Synthesis, stereochemistry, and opioid receptor binding activity of heterocyclic analogues of BW373U86
Authors: Boswell G. Evan , Mcnutt Robert W. , Bubacz Dulce G. , Davis Ann O. , Chang Kwen‐Jen 
Published: March 2009

AbstractThe synthesis of a series of heterocyclic analogues of (±)‐4‐((αR*)‐α‐((2S*,5R*)‐4‐allyl‐2,5‐dimethyl‐1‐piperazmyl)‐3‐hydroxybenzyl)‐N,N‐diethylbenzarrude (BW373U86) for screening against opioid receptors is described. The intermediate α‐heterocyclic benzyl alcohols24were synthesized either by low temperature reaction of lithioheterocycles with 3‐((tert‐butyldimethylsilyl)oxy)benzaldehyde (10) or by reaction of 3‐((tert‐butyldimethylsilyl)oxy)phenylmagnesium bromide (19) with heterocyclic carbaldehydes. The α‐heterocyclic benzyl alcohols24were converted to chloromethines (25) with thionyl chloride and used to alkylate withtrans‐1‐allyl‐2,5‐dimethylpiperazine (5) to give diastereomeric pairs of the target compounds. The bromoheterocycles were then derivatized to produce amides. Compounds that are potent and selective for the 5 or μ opioid receptors and some mixed δ/μ analogues are reported.
Synthesis and anti‐tetrabenazine activity of c‐3 analogues of dimethyl‐2‐phenylmorpholines
Authors: Boswell G. Evan , Musso David L. , Kelley James L. , Soroko Francis E. , Cooper Barret R. 
Published: March 2009

AbstractA series of analogues of 2‐phenylmorpholines with alkyl substituents at the C‐3 position were synthesized for anti‐tetrabenazine (anti‐TBZ) testing in mice. The target compounds were prepared by reaction of (2‐bromoalkyl) phenyl ketones 21a‐h with the appropriate aminoalcohol 20a‐b to form morpholinols 22a‐h. Hydride reduction of the morpholinols gave aminodiols 23a‐h which were cyclized to morpholines 6, 8, 10–12, 14–16, 18 and 19 by acid catalaysis. Compounds 7, 9, 13 and 17 were prepared by reductive formylation. The smaller straight chain substituents of 6, 8, 12 and 15, and the beta branching of the iso‐butyl group of 16 were well tolerated; anti‐tetrabenazine ED50′s were comparable to compounds 2–5. The α‐branched, N‐methylated, and side chain aryl derivatives were less active.
Polycyclic N‐heterocyclic compounds. 48. syntheses of furo[2,3‐h]‐[1,6]naphthyridine and imidazo(or pyrimido)[2,1‐f]‐[1,6]naphthyridines with rearrangement
Authors: Sasaki Kenji , Rouf Abu Shara Shamsur , Hirota Takashi 
Published: March 2009

AbstractThe formation of a novel ring system, furo[2,3‐h][1,6]naphthyridine via the Smiles rearrangement and intramolecular cyclization is described. Cyclization of 5‐(ω‐hydroxyalkylamino)‐8‐methyl‐1,2‐dihydrofuro[2,3‐h][1,6]naphthyridines provided novel spiro compound with rearrangement.
Synthesis of two novel ring systems via photocyclization: Thieno[2′,3′:4,5]thieno[2,3‐c][1,10]phenanthroline and thieno[3′,2′:4,5]thieno[2,3‐c][1,10]phenanthroline
Authors: Halverson Aileen Pfleider , Castle Lyle W. , Castle Raymond N. 
Published: March 2009

AbstractThe synthesis of thieno[2′,3′:4,5]thieno[2,3‐c][1,10]phenanthroline (5) and thieno[3′,2′:4,5]thieno‐[2,3‐c][1,10]phenanthroline (10) are described. Each compound was obtained in four steps from known starting materials. The basic skeleton of the molecule and of the phenanthroline ring were formed via photocyclization. The total assignment of 1H‐nmr spectra was accomplished with the aid of two‐dimensional nmr methods.
Reactivity of aminopyrroles: Protonation
Authors: Cirrincione Girolamo , Almerico Anna Maria , Diana Patrizia , Barraja Paola , Mingoia Francesco , Grimaudo Stefania , Dattolo Gaetano , Aiello Enrico 
Published: March 2009

AbstractThe behaviour of 2‐ and 3‐aminopyrroles towards protonation is similar. In dimethyl sulphoxide/trifluoroacetic acid they are protonated at the exocyclic nitrogen, whereas in pure trifluoroacetic acid, protonation at the 5‐ and/or 3‐position of the ring takes place.
2,6‐Diarylhexahydro‐4‐pyridazinols by acid‐catalyzed cyclization of benzaldehyde aryl‐2‐(2‐propenyl)hydrazones
Authors: Bakthavatchalam Rajagopal , Ciganek Engelbert , Calabrese Joseph C. 
Published: March 2009

AbstractTreatment of benzaldehyde l‐(2‐propenyl)‐4‐methylsulfonylphenylhydrazone (1f) with 45% sulfuric acid gave 2‐(4‐methylsulfonylphenyl)‐6‐phenylhexahydro‐4‐pyridazinol (2f) in 35% yield rather than the expected 1‐(4‐methylsulfonylphenyl)‐1‐(2‐propenyl)hydrazine. The halogen‐substituted hydrazones 1c‐1e and benzaldehyde 1‐(2‐methyl‐2‐propenyl)phenylhydrazone (1b) gave similar results.
Reaction of dichlorocarbene with 2,3‐dihydro‐5,6‐dimethyl‐1,4‐oxathiin and 2,3‐dihydro‐5,6‐dimethyl‐1,4‐dithiin
Authors: Brewer A. D. , Znotins A. A. 
Published: March 2009

AbstractDichlorocarbene, generated from ethyl trichloroacetate and sodium ethoxide, reacts with 2,3‐dimethyl‐5,6‐dihydro‐1,4‐oxathiin to give 7,7‐dichloro‐1,6‐dimethyl‐2‐oxa‐5‐thiabicyclo[4,1,0]heptane, and with 2,3‐dimethyl‐5,6‐dihydro‐1,4‐dithiin to give 6‐chloro‐2,3‐dihydro‐7‐methyl 5‐methylene‐5(H)‐1,4‐dithiepin. Both products were oxidised to the corresponding sulfone.
A classification of organic redox reactions and writing balanced equations for them, with special attention to heteroatoms and heterocyclic compounds
Authors: Klemm L. H. 
Published: March 2009

AbstractOrganic redox reactions are classified either as atom transfers (balanced by inspection) or as more complex transformations (balanced by change in oxidation number, ON, by change in DOX value, by electrochemical half‐reaction, or by simultaneous linear algebraic equations). Examples presented include not only involvement of hydrogen or oxygen but also extensions to halogens, nitrogen, phosphorus, and sulfur. Complex reactions are subdivided into ones which proceed (a) without change in the number of carbon atoms per molecule, (b) with fragmentation of the carbon assemblage in the starting material, or (c) with condensation of two or more molecules of organic starting materials.
Synthesis of some highly functionalized thiophene‐3‐carboxylates and alcohols
Authors: Coppola Gary M. , Damon Robert E. , Yu Harvey 
Published: March 2009

AbstractHighly functionalized thiophenes are prepared by two methods. The first uses a lithium‐halogen exchange reaction on a trisubstituted 5‐bromothiophene 25 to generate the corresponding 5‐lithiothiophene 26 which is then reacted with either dimethylformamide or formaldehyde to give the 5‐formyl 28 or 5‐hydroxymethylthiophene derivative 31 in good yields. These are further transformed to other tetrasubstituted thiophenes. The second method assembles the thiophene ring from three components: a benzyl mercaptan, an aldehyde, and a vinylphosphonate 10. Thus, the benzyl mercaptan is dilithiated then reacted with an appropriate aldehyde to afford a 2‐mercapto‐2‐phenylethanol derivative 37. Michael addition of 37 to 10 followed by oxidation of the hydroxyl group furnishes ketophosphonate 39. An intramolecular Wittig‐type reaction produces the thiophene skeleton.
Ring chain transformation of γ‐keto‐δ‐crotonolactones: A convenient synthesis of 1,4‐piperazinones, 1,4‐thiazinones and 1,4‐diazepinones
Authors: Apostolopoulos Costas D. , Georgiadis Minas P. , Couladouros Elias A. 
Published: March 2009

AbstractA new procedure for the efficient synthesis of 1,4‐piperazinones, 1,4‐thiazinones and 1,4‐diazepinones is presented. The reaction is based on a ring chain transformation of γ‐keto‐δ‐crotonolactones induced by 1,2‐ or 1,3‐diamino‐ (or thiamino‐) binucleophiles. The reaction sequence of this transformation is also discussed.
Synthesis of novel heterocycles related to the dynemicin a ring skeleton
Authors: Nicolaou K. C. , Gross Jonathan L. , Kerr Michael A. 
Published: March 2009

AbstractStudies directed towards the construction of the CDE ring framework of dynemycin A (1) are reported. A series of quinoline based dienophiles containing an activating group (e.g. 5, Scheme 1), reacted with acyclic dienes (e.g. 4, Scheme 1) in a Diels‐Alder fashion under increased pressure to afford a variety of heterocyclic systems related to the CDE skeleton of dynemycin A. Reaction of dienophile 15 with cyclic diene 29 led to the novel hetereocycle 34 whereas attempted decarbonylation of 41 led to a novel rhodium‐promoted intramolecular carbonylation of the terminal acetylene furnishing compound 43.
The lead tetraacetate oxidation of bisacetylhydrazones of α‐dicarbonyl compounds
Authors: Hadjiantoniou‐Maroulis Constantina P. , Vantsiouri Anastasia , Maroulis Apostolos J. 
Published: March 2009

AbstractThe oxidative cyclization of the title compounds results in generally two different kinds of products. The first, 1‐(N,N‐bisacetylamino)‐1,2,3‐triazole7(R3= CH3) is the primary product, while the second, 1‐N‐acetylamino‐1,2,3‐triazole8(R3= CH3), when observed, is obtainedviahydrolysis from the former during work‐up and separation of the reaction mixture. The primary products are considered as resulting from intramolecular nucleophilic attack on the acetyl group, of the presumed zwitterionic intermediate5(R3= CH3), by theNof the ambidentN‐acetylimine site of5.
Formation and crystal structure of an exocyclic enol δ‐lactone obtained from dimedone and trimethylsilylethynyl phenyliodonium triflate
Authors: Nikas Spyros , Rodios Nestor A. , Varvoglis Anastasios , Terzis Aristidis , Raptopoulou Catherine R. 
Published: March 2009

AbstractThe reaction between dimedone anion and trimethylsilylethynyl phenyliodonium triflate leads to the formation of 4,4‐dimethyl‐6‐(1,5‐bistrimethylsilylpentane‐1,4‐diyne‐3‐ylidene)‐δ‐valerolactone, whose crystal structure has been determined.
Reaction of 9‐substituted 1‐aminoadenine with hydrazine
Authors: Asano Shoji , Itano Keiji , Kohda Kohfuku , Yamagata Yuriko 
Published: March 2009

AbstractReaction of 9‐substituted (methyl or benzyl) 1‐aminoadenines 1 with hydrazine afforded 9‐substituted 6‐hydrazinopurines 2 and 1‐substituted 5‐ammo‐4‐(4‐amino‐1,2,4‐triazol‐3‐yl)imidazole (4). The product ratio of 2 to 4 rose with increasing amounts of methanol used as the solvent. When the same reaction was carried out using 1,9‐dimethyladenine instead of 1, compounds 2 and 4 were also obtained with N6,9‐dimethyladenine. A possible mechanism for formation of 2 and 4 is discussed.
Synthesis and reduction of 2,2‐diaryl‐1‐nitroethylenes by using a chiral and a non chiral NADH model in the pyrrolopyridine series
Authors: Levacher Vincent , Valque Claude , Coupa Sophie , Dupas Georges , Quéguiner Guy , Bourguignon Jean 
Published: March 2009

AbstractReduction of 2,2‐diphenyl‐1‐nitroethylene (1) and 2‐(2‐pyridyl)‐2‐phenyl‐1‐nitroethylene (5) is achieved by using the NADH model in the pyrrolopyridine series 2a to give 2,2‐diphenyl‐1‐nitroethane (3) and 2‐(2‐pyridyl)‐2‐phenyl‐1‐nitroethane (7) respectively in 40% yield. The asymmetric reduction of 2‐(2‐pyridyl)‐2‐phenyl‐1‐nitroethylene by the chiral NADH model 2b is studied. Thus, 2‐(2‐pyridyl)‐2‐phenyl‐1‐nitroethane (7) is obtained in 15 to 32% yield. The stereocontrol of the reduction proved to be dependent on the amount of magnesium ions.
Access to aza‐γ‐carbolines by annulation reaction of amino derivatives of imidazo[1,2‐α]pyridine
Authors: Jouanisson Anne , Couquelet Jacques , Teulade Jean‐Claude , Chavignon Olivier , Chabard Jean‐Louis , Dauphin GÉRard 
Published: March 2009

AbstractDifferent routes of formation of aza‐γ‐carboline ring‐system are discussed. In addition the reactivity of an amino derivative in comparison with an iminophosphorane compound is investigated.
Photocyclization of 2‐[1]benzothien‐3‐yl)‐3‐phenylpropenoic acids
Authors: Tominaga Yoshinori , Castle Lyle W. , Castle Raymond N. 
Published: March 2009

AbstractPhotocyclization of the substituted 2‐([1]benzothien‐3‐yl)‐3‐phenylpropenoic acids 3a‐c in the presence of iodine and air in a benzene‐cyclohexane mixture afforded a separable mixture of three compounds, benzo[b]naphtho[2,1‐d]thiophene‐6‐carboxylic acids 4a‐c, 6H‐benzo[b]naphtho[2,3‐d]thiopyran‐6‐ones 5a‐c, and 10‐methoxy‐2‐methyl‐6H‐benzo[b]naphtho[2,3‐d]pyran‐6‐one (6).
Regioselective synthesis of 9‐substituted‐8‐azaguanines (5‐amino‐3‐substituted‐3,6‐dihydro‐7H‐1,2,3‐triazolo[4,5‐d]pyrimidin‐7‐one)
Authors: Sznaidman Marcos L. , Beauchamp Lilia M. 
Published: March 2009

AbstractBy modifying previously described methods for the synthesis of 9‐substituted‐guanines from imidazoles, we have developed a new procedure for the regioselective synthesis of 9‐substituted‐8‐azaguanines (5‐amino‐3‐substituted‐3,6‐dihydro‐7H‐1,2,3‐triazolo[4,5‐d]pyrimidin‐7‐one) from triazoles in high yields. The method seems suitable for the introduction of a variety of substituents including sugars, carbocyclic, acyclic and carboacyclic chains.
Ring transformations of heterocyclic compounds. XV. N‐(2‐hydroxyphenyl) substituted 2‐alkylamino‐4,6‐diarylbenzophenones by ring transformation of 2,4,6‐triarylpyrylium salts with anhydrobases of benzoxazolium salts
Authors: Zimmermann Thomas , Abram Ulrich , Schmidt Klaus 
Published: March 2009

AbstractThe synthesis of hitherto unknown N‐(2‐hydroxyphenyl) substituted 2‐alkylamino‐4,6‐diarylbenzophenones 3 from 2,4,6‐triarylpyrylium salts 1 and 3‐alkyl‐2‐methylbenzoxazolium salts 2 in the presence of triethylamine in ethanol by a 2,5‐[C4+C2] pyrylium ring transformation is reported. Structure elucidation is performed by an X‐ray crystal structure determination of the benzophenone 3a. Spectroscopic data of the transformation products and their mode of formation via anhydrobases of the salts 2 are discussed.
Ring transformations of heterocyclic compounds. XIV. Ring transformations of pyrylium and thiopyrylium salts with anhydro‐bases derived from 1H‐benzimidazolium and benzothiazolium salts: An easy access to 2‐(2,4,6‐triarylphenyl) 1H‐benzimidazolium and benzothiazolium derivatives
Authors: Zimmermann Thomas , Schmidt Klaus 
Published: March 2009

AbstractThe preparation of former unknown 2‐(2,4,6‐triarylphenyl) substituted 1H‐benzimidazolium perchlorates 7 and benzothiazolium perchlorates 8 from 2‐methyl substituted derivatives 5/6 by a 2,6‐[C5+C] ring transformation of 2,4,6‐triarylpyrylium and 2,4,6‐triarylthiopyrylium salts 1/9 in the presence of an appropriate base (7: sodium ethoxide, 8: sodium acetate) is reported. Spectroscopic data of the transformation products and their mode of formation via anhydrobases of the salts 5/6 are discussed.
Cycloaddition reactions of 2H‐benzo[b]thiete and conjugated cyclic dienes
Authors: Gröschl Dieter , Meier Herbert 
Published: March 2009

Abstract2H‐Benzo[b]thiete 1 reacts with cyclopentadiene 3 in consecutive [8π + 2π]cycloadditions yielding the condensed heterocycles 6–8. Tetracyclone 9 on the other hand gives only the monoadduct 10. An [8π + 8π]cycloaddition can be observed for 1 and diphenylisobenzofuran 11. The related π system 13 shows again consecutive [477π + 27π]processes (1 + 13 ← 14, 15).
Synthesis and evaluation of 1H‐pyrazolo[3,4‐b]quinoxalines and 1‐aryl‐3‐quinoxalinyl‐1,2,4‐triazole as antibacterial agent
Authors: Kim Ho Sik , Chung Ju Young , Kim Eun Kyoung , Park Yong Tae , Hong Young Seuk , Lee Man Kil , Kurasawa Yoshihisa , Takada Atsushi 
Published: March 2009

AbstractNovel 1H‐pyrazolo[3,4‐b]quinoxalines (flavazoles) 14, 15 and 1‐aryl‐3‐quinoxalinyl‐1,2,4‐triazole 17 were synthesized from the ester 11 via various hydrazones 12, 13 and 16. In the antibacterial screening test of compounds 12–17, compound 14 showed a relatively high antibacterial activity, wherein the MIC value was 25 μg/ml against Bacillus licheniformis KTCC 21425 and Cellulomonas sp. and 50 μg/ml against Salmonella typhimurium KCTC 1925 and Flavobacterium devolans.
Synthesis of novel 3‐alkoxy‐ and 3‐alkylthioindole and ‐benzofuran‐2‐carboxamides
Authors: Unangst Paul C. , Connor David T. , Miller Steven R. 
Published: March 2009

AbstractThe preparation of a series of 3,5‐substituted indole‐ and benzofuran‐2‐carboxamides is described. A 3‐alkoxy‐5‐hydroxybenzofuran was prepared by elaboration of a benzyloxy salicylate ester. A related 3‐alkylthiobenzofuran was obtained by the addition of thionyl chloride and isopropylmagnesium chloride to a benzofuran ester. A series of 3‐(methylthio)indoles was prepared from an indole sulfonium salt intermediate.