bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coupling reactions of aryl and heteroaryl halides with a trimethylsilylethynylpyrazine
Authors: Akita Yasuo , Kanekawa Hideta , Kawasaki Tatsuya , Shiratori Ikuko , Ohta Akihiro 
Published: April 2009

AbstractBy the coupling reactions of trimethylsilylacetylene and 2‐chloro‐3,6‐diisobutylpyrazine, 3,6‐diisobutyl‐2‐trimethylsilylethynylpyrazine or 1,2‐bis(3,6‐diisobutylpyrazin‐2‐yl)acetylene was obtained, depending on the solvent used. The former substance coupled with various aryl and heteroaryl halides to give 1‐aryl‐2‐pyrazin‐ylacetylenes.
Ring transformation of pyrimidines to pyridines. Synthesis of 4‐alkylaminopyridin‐2‐ones by alkaline hydrolysis of 6‐(2‐dimethylaminovinyl)uracils
Authors: Hirota Kosaku , Abe Yoshio , Asao Tetsuji , Senda Shigeo , Kitade Yukio , Maki Yoshifumi 
Published: April 2009

AbstractAlkaline hydrolysis of 1,3‐disubstituted 6‐(2‐dimethylaminovinyl)uracils 2 induced a novel ring transformation giving 4‐alkylaminopyridin‐2‐ones 3 via ring‐opening and ring‐closure processes. The 4‐methylamino‐3‐nitropyridin‐2‐one (3a) thus obtained was employed for the synthesis of 3‐deazahypoxanthine derivative 8. 4‐Alkylamino‐3‐cyanopyridin‐2‐ones 11, ricinine analogs, were also prepared by the reaction of 4‐chloro‐3‐cyano‐1‐methylpyridin‐2‐one (10) with amines.
Synthesis of pyrrolo[1,2‐b]cinnolines
Authors: Hamer R. Richard L. , Sekerak Danette , Effland Richard C. , Klein Joseph T. 
Published: April 2009

AbstractThe synthesis of the pyrrolo[1,2‐b]cinnoline analogs 2 and 4–13 is described. The key step of this synthesis involves an intramolecular aromatic halide displacement on [2‐(2‐halobenzoyl)pyrrol‐1‐yl]carbamic acid esters. Several reactions of these cinnoline analogs with electrophilic reagents have been investigated.
Facile synthesis and antifungal activity of 3‐substituted 4‐amino‐8‐ethoxycarbonylpyrazolo[5,1‐c][1,2,4]triazines and pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6‐b][1,5]benzodiazepines
Authors: Kurasawa Yoshihisa , Kanoh Megumi , Kamigaki Yumiko , Okiyama Mari , Takada Atsushi , Okamoto Yoshihisa 
Published: April 2009

AbstractThe reactions of the pyrazole‐5‐diazonium salt 3 with malononitrile and ethyl cyanoacetate gave 4‐amino‐3‐cyano‐8‐ethoxycarbonylpyrazolo[5,1‐c][1,2,4]triazine 7 and 4‐amino‐3,8‐bisethoxycarbonylpyrazolo[5,1‐c]‐[1,2,4]triazine 8, whose reactions with p‐chloroaniline hydrochloride afforded 4‐amino‐8‐ethoxycarbonyl‐3‐(p‐chlorophenyl)amidinopyrazolo[5,1‐c][1,2,4]triazine 9 and 4‐amino‐8‐ethoxycarbonyl‐3‐(p‐chlorophenyl)car‐bamoylpyrazolo[5,1‐c][1,2,4]triazine 10, respectively. The reactions of 7 and 8 with o‐phenylenediamine di‐hydrochloride provided 9‐ethoxycarbonyl‐13H‐spiro[benzimidazole‐2′(3′H),6(5H)‐pyrazolo[1,5′:3,4][1,2,4]tri‐azino[5,6‐b][1,5]benzodiazepine] hydrochloride 11a and 9‐ethoxycarbonyl‐6‐oxo‐13H‐5,6‐dihydropyrazolo‐[1′,5′:3,4][1,2,4]triazino[5,6‐b][1,5]benzodiazepine 12, respectively. The antifungal activity of the above compounds was described.
New derivatives of pyrimidine nucleosides: Synthesis, physico‐chemical properties and biological activity
Authors: De Napoli Lorenzo , Mayol Luciano , Bartolucci Simonetta , Piccialli Gennaro , Rossi Mosé , Santacroce Ciro 
Published: April 2009

AbstractThe paper reports the synthesis and physico‐chemical data of eight new pyrimidine nucleosides C‐4 substituted and two imidazo[1,2‐c]pyrimidine nucleosides as well as preliminary results of their biological effects on neuroblastoma cells in culture.
A convenient synthesis of 5‐substituted‐7‐β‐D‐arabinofuranosylpyrrolo[2,3‐d]pyrimidines structurally related to the antibiotics toyocamycin and sangivamycin
Authors: Ramasamy Kandasamy , Robins Roland K. , Revankar Ganapathi R. 
Published: April 2009

Abstract4‐Amino‐7‐(2,3,5‐tri‐O‐benzyl‐β‐D‐arabinofuranosyl)pyrrolo[2,3‐d]pyrimidine‐5‐carbonitrile (6a), prepared from 2‐ethoxymethyleneamino‐5‐bromopyrrole‐3,4‐dicarbonitrile (4), was debenzylated with boron trichloride to give ara‐toyocamycin (6b). Further functional group transformation of 6b provided a route to 4‐amino‐7‐β‐D‐arabinofuranosylpyrrolo[2,3‐d]pyrimidine‐5‐thiocarboxamide (ara‐thiosangivamycin, 7a), and the corresponding 5‐carboxamidoxime 8a and 5‐carboxamidine 8b derivatives. Phosphorylation of unprotected 7a with phosphorus oxychloride gave ara‐thiosangivamycin 5′‐monophosphate (7b). 2′‐O‐Acetyl‐ara‐thiosangivamycin (10b) was prepared as a prodrug by acetylation of 9a, followed by deprotection of the t‐butyldimethylsilyl groups under acidic conditions without acyl migration.
Relative reactivity in the condensation of 2H‐isoindole‐ and 2H‐indazole‐4,7‐dione derivatives with o‐aminobenzenethiol and its derivatives
Authors: Nan'Ya Seiko , Katsuraya Kaname , Ueno Yoshio , Maekawa Eturô 
Published: April 2009

AbstractThe effects of substituents on the condensation of o‐aminobenzenethiol derivatives with 2H‐isoindole‐ and 2H‐indazole‐4,7‐dione derivatives were studied by competitive reactions.
The preparation of 3‐hydrazino‐4‐hydroxy‐ and 3‐hydrazino‐4‐methoxypyridine from sydnones
Authors: El‐Bakoush M. M. , Parrick J. 
Published: April 2009

Abstract3‐Hydrazino‐4‐hydroxy‐ and 3‐hydrazino‐4‐methoxypyridines, which could not be obtained by reduction of the corresponding diazonium salts, have seen prepared by decomposition of N‐(4‐substituted‐pyrid‐3‐yl)‐syndones.
A novel approach to synthesis of the cinnoline ring system via organoiron(cyclopentadienyl) complexes
Authors: Sutherland Ronald G. , Abd‐El‐Aziz Alaa S. , Piórko Adam , Gill Udai S. , Lee Choi Chuck 
Published: April 2009

AbstractAn efficient synthesis of 3‐mono or 3,4‐disubstituted cinnolines from (o‐dichlorobenzene)(cyclopentadienyl)iron hexafluorophosphate in three or four steps has been achieved. o‐Chlorophenyl‐alkyl or alkylaryl ketone complexes obtained from the o‐dichlorobenzene complex upon treatment with enolate anions, react with hydrazine forming 3‐mono or 3,4‐disubstituted 1,4‐dihydrocinnoline complexes. Treatment of the later with sodium amide leads to an aromatization‐demetallation reaction resulting in formation of cinnolines, i.e. 3‐methyl‐, 3‐phenyl‐ and 3,4‐dimethylcinnoline. The influence of substituents bonded to the carbon atom adjacent to the complexed benzene ring in o‐chlorophenyl ‐alkyl or ‐alkylaryl ketone prior to cyclization on the cyclization reaction is discussed.
Reaction of N‐(4‐pyridylmethyl)‐3,5‐dimethylbenzamide N‐oxide with acidic compounds in the presence of acetic anhydride: Discussion of the mechanism
Authors: Braña Miguel F. , Castellano José M. , Donoso Rosa , Rodríguez María L. López , Yunta Maria J. R. 
Published: April 2009

AbstractThe mechanism of N‐(4‐pyridylmethyl)‐3,5‐dimethylbenzamide N‐oxide with acidic compounds in the presence of acetic anhydride is presented.
Pyridinethiones. XV. 3‐Methylthio‐2‐pentene‐1,5‐diones as synthons for 4‐methylthio‐2(1H)‐pyridinethiones, and synthesis of 4‐methylene‐1,4‐dihydropyridines
Authors: Becher Jan , Hansen Poul 
Published: April 2009

AbstractStarting from α‐oxoketene dithioacetals the 3‐methyithio‐1,5‐pentenedione enolates 4 obtained from ketones 3 give 4‐methylthio‐2(1H)‐pyridinethiones with isothiocyanates. Enolates 4 can be alkylated with methyl iodide at C‐2, giving 5‐methyl‐4‐methylthio‐2‐(1H)‐pyridmethiones with isothiocyanates. The S‐alkylated pyridinethiones react with the anion of malodinitrile, giving 4‐(1,1‐dicyanomethylene)‐1,4‐dihydropyridines.
Condensed 1,2,4‐triazines. Synthesis and reactions of some condensed benzo[e]as‐triazines
Authors: Eid Mohga M. , Mansour A. K. 
Published: April 2009

Abstract2‐o‐Chlorophenyl‐2H‐naphtho[1,2‐d]v‐triazole‐4,5‐quinone condenses with semicarbazide and some of its derivatives at the 4 position and the products cyclize into the corresponding 1,2,4‐triazines. Reactions of these triazines with some reagents are described.
Furopyridines. VIII. Molecular structure and two‐dimensional NMR spectral assignment of 2,14‐dimethyl‐8aβ‐hydroxy‐7,10‐dioxo‐5β,6β‐(propano)‐6α,8α‐(ethanoimino)‐trans‐perhydroisoquinoline
Authors: Shiotani Shunsaku , Morita Hiroyuki , Ishida Toshimasa , In Yasuko , Tatemitsu Hitoshi 
Published: April 2009

AbstractThis paper reports the two‐dimensional nmr spectral assignment and the X‐ray structural determination of 2,14‐dimethyl‐8β‐hydroxy‐7,10‐dioxo‐5β,6β‐(propano)‐6α,8α‐(ethanoimino)‐trans‐perhydroisoquinoline V which was obtained from 7,10‐dimethyl‐2β‐hydroxy‐14‐oxo‐2,3‐(methanoiminoethano)‐3β,4β‐(propano)‐3,4,5,6,7,8‐hexahydro‐2H‐pyrano[2,3‐c]pyridine IV by isomerization with hydrochloric acid. Both the compounds IV and V afforded the same dimethiodide IV‐2MeI, while the configurational isomer 2,14‐dimethyl‐8aβ‐hydroxy‐7,10‐dioxo‐5α,6β‐(propano)‐6α,8α‐(ethanoimino)‐trans‐perhydroisoquinoline III gave monomethiodide III‐Mel. The structures of these methiodides were also confirmed by X‐ray analysis.
13C NMR spectra of 1‐(N‐arylidene)amino‐1,2,3‐triazoles
Authors: Rodios N. A. , Tsoleridis C. A. , Alexandrou N. E. 
Published: April 2009

AbstractThe 13C nmr spectra of several 1‐(N‐arylidene)amino‐1,2,3‐triazoles were determined. The long range influence of substituents on 13C resonances of triazole and C = N carbon atoms was examined and a correlation of their chemical shifts with net charge densities (qπ + σ) calculated by the CNDO/2 method was made. It was also shown that the dependence of the coupling constants 1J(CH) for C = N carbon on the substituents is better correlated using electrons in bond values instead of charge densities.
Reaction of 4‐styryl‐1,2,3‐benzoxathiazine 2,2‐dioxides with diazomethane: Synthesis of a novel heterocyclic system
Authors: Tripathi Manisha , Dhar Durga Nath 
Published: April 2009

AbstractA new class of heterocyclic system, 3a‐f, has been synthesized by reacting diazomethane with 4‐styryl‐1,2,3‐benzoxathiazine 2,2‐dioxides 1a‐f. Diazomethane adds to the > C = S group of these compounds.
Synthesis of heterocyclic compounds from 3‐acetyl‐3‐chloropropyl acetate
Authors: D'Amico John J. , Bellinger Frederic G. , Thompson Michael , Freeman John J. , Dahl William E. , Pustinger John V. 
Published: April 2009

AbstractThe reaction of the potassium salt of 2‐mercaptobenzimidazole with 3‐acetyl‐3‐chloropropyl acetate afforded the novel heterocyclic compound 1. When solutions of 1 in deuteriodimethylsulfoxide or deuteriomethanol were allowed to stand at room temperatures for 15 minutes and 19 days, respectively, ring opening of 1 occurred to give the precursor, 3‐acetyl‐3‐(2‐benzimidazolthio)propyl‐1‐ol. The treatment of 1 with p‐fluorophenyl isocyanate furnished the carbanilate 2. The reaction of ammonium dithiocarbamate with the above chloroketone afforded the 2‐thiazolethione 3. Possible mechanisms and supporting nmr, ir, mass spectral data for 1–3 and single crystal X‐ray analysis for 2 are discussed.
Regioselective proton‐catalyzed diarylmethylation of indoles with 9H‐xanthydrol, dibenzosuberenol, and bis[4‐dimethylaminophenyl]methanol
Authors: Pindur Ulf , Deschner Rainer 
Published: April 2009

Abstract3‐Isopropylindole (4) is xanthenylated both at N‐1 (stereocontrolled major reaction), C‐2, and on the phenyl nucleus of the indole skeleton by xanthydrol (1). Other carbinols such as dibenzosuberenol (2) and bis[4‐dimethylaminophenyl]methanol (3) with lower electrophilic SN1 activities than 1 do not react with 4 but do react very selectively with simple methylindoles to form diarylmethylated derivatives.
Furopyridines. IX. Syntheses and properties of 3‐ethoxy derivatives of furo[2,3‐b]‐, furo[3,2‐b]‐, furo[2,3‐c]‐ and furo[3,2‐c]pyridine
Authors: Shiotani Shunsaku , Morita Hiroyuki , Ishida Toshimasa , In Yasuko 
Published: April 2009

AbstractReaction of ethyl 3‐ethoxycarbonylmethoxyfuropyridine‐2‐carboxylates 2a‐2d with sodium ethoxide afforded 3‐ethoxy derivatives 3a‐3d which converted to 3‐ethoxyfuropyridines 5a‐5d by hydrolysis and decarboxylation of the ester group. Vilsmeier reaction of 5a and 5b gave 2‐formyl‐3‐ethoxy derivatives 6a and 6b and 2‐formyl‐3‐chloro derivatives 7a and 7b, while 5c and 5d did not give any formyl compound. Bromination of 3‐ethoxyfuropyridines with 1 equivalent mole of bromine gave 2‐bromo‐3‐ethoxyfuropyridines 9a‐9d, whereas reaction with 3 equivalents of bromine yielded 2,2‐dibromo‐3,3‐diethoxy‐2,3‐dihydrofuropyridines (10a and 10b) and/or 2‐bromo‐3,3‐diethoxy‐2,3‐dihydrofuropyridines 11b, 11c and 11d. Treatment of compounds 5a‐5d with n‐butyllithium in hexane‐tetrahydrofuran at −70° and subsequent addition of N,N‐dimethylformamide yielded 2‐formyl derivatives 6a‐6d.
Condensed 1,3‐benzothiazinones. 1. Facile synthesis of 2‐amino‐1,2,4‐triazolo[5,1‐b][1,3]‐benzothiazin‐9‐one
Authors: Liu Kang‐Chien , Shih Bi‐Jane , Chern Ji‐Wang 
Published: April 2009

AbstractTreating 2‐mercaptobenzohydrazide (1a) with cyanogen bromide gave 3‐amino‐2‐imino‐3,4‐dihydro‐2.H‐1,3‐benzothiazin‐4‐one (2a). This compound underwent further cyclocondensation with a second molecule of cyanogen bromide or S‐methylisothiourea sulfate to afford the biologically interesting 2‐amino‐1,2,4‐triazolo‐[5,1‐b][1,3]benzothiazin‐9‐one (3c). Compound 3c could also be prepared directly from 1a by treating with excess amount of cyanogen bromide in more satisfactory yield.
Studies of the reaction of substituted 1,2‐dithiole‐3‐thiones and ‐3‐ones with sodium cyanide in acetonitrile
Authors: Largeron M. , Martens T. , Fleury M. B. 
Published: April 2009

AbstractThe reactions of substituted 1,2‐dithiole‐3‐thiones and ‐3‐ones with sodium cyanide, in acetonitrile, afford convenient routes to indolizine, pyrrolo[1,2‐a]pyrazine and 4H‐1,3‐thiazin‐4‐one species.
Synthesis of unsymmetric bile pigments: Mesobilirubin‐VIIIα, 17‐desvinyl‐17‐ethyl‐bilirubin‐VIIIα and 12‐despropionic acid‐12‐ethyl‐mesobilirubin‐XIIIα
Authors: Trull Francesc R. , Lightner David A. 
Published: April 2009

AbstractThe unnatural bile pigments 17‐desvinyl‐17‐ethylbilirubin‐VIIIα, mesobilirubin‐VIIIα and 12‐despropionic acid‐12‐ethyl mesobilirubin‐XIIIα were synthesized via (1) “reverse scrambling” of bilirubin‐XIIIα or mesobilirubin‐IXα with mesobilirubin‐IVα or etiobilirubin‐IV‐γ or (2) following coupling of xanthobilirubic acid methyl ester with ψ‐xanthobilirubic acid methyl ester, or coupling of xanthobilirubic acid methyl ester with kryptopyrromethenone.
A new and convenient synthesis of alkyl and aryl pyrimidines
Authors: Martínez A. García , Herrera A. , Martínez R. , Teso E. , García A. , Osío J. , Pargada L. , Unanue R. , Subramanian L. R. , Hanack Michael 
Published: April 2009

AbstractVinyl triflates 1, which are obtained easily from the corresponding ketones, react in an excess of pure nitrile (80°/20 hours) to form tri‐ and tetra‐substituted alkyl and arylpyrimidines 4 and 5 in good yields (45–87%). An isomeric mixture of pyrimidines 4 and 5 is formed from Inflate 1 when R1 ≠ R2 ≠ H. The reaction proceeds by nitrile‐catalyzed elimination‐addition mechanism.
Photochemistry of ommochromes and related compounds. Part II
Authors: Bolognese A. , Liberatore R. , Scherillo G. 
Published: April 2009

AbstractThe visible light irradiated solutions of the 1‐methyl‐1‐(1′‐[11‐(β‐aspartoyl‐methyl ester‐imino)]ethenyl]‐ketal‐1H,5H‐pyrido[3,2‐a]phenoxazin‐5‐one (1) and the 1,5‐dimethoxy‐11‐(β‐aspartoyl‐N‐acetyl‐methyl ester)‐pyrido[3,2‐a]phenoxazine (2) [1], in methanol and acidic methanol, are examined. Both methanolic solutions undergo light induced transformation according to an opening of the phenoxazinone and phenoxazine systems, not reversible in darkness. On the contrary, 1 and 2 in methanol‐acid solutions, under visible light irradiation, yield a solvent photoaddition, reversible in darkness.Some phototransformation products are examined and a plausible mechanism, for the reactions explanation, is suggested.
Synthesis and anticonvulsant activity of 1‐benzyl‐4‐alkylamino‐1H‐imidazo[4,5‐c]pyridines
Authors: Kelley James L. , Linn James A. , Hideout Janet L. , Soroko Francis E. 
Published: April 2009

AbstractFour 3‐deaza analogues of the potent anticonvulsant purine, BW A78U, were synthesized and tested for anticonvulsant activity. The imidazo[4,5‐c]pyridines 9–12 were prepared in two steps from 4‐chloro‐1H‐imidazo[4,5‐c]pyridine (2). The compounds were potent anticonvulsant agents against maximal electroshock‐induced seizures in rats with i.p. ED50 ranging from 2 to 3.5 mg/kg. However, these 3‐deazapurines were appreciably more toxic than BW A78U, which precluded their development as potential antiepileptic agents.
Ring transformation of 1,5‐benzoxazepines into spirobenzoxazoles. Synthesis of pyrazolo[1′,5′:3,4][1,2,4]triazino‐[5,6‐b][1,5]benzoxazepines and spiro[benzoxazole‐2′(3′H),4(1H)‐pyrazolo[5,1‐c][1,2,4]triazines]
Authors: Kurasawa Yoshihisa , Okiyama Mari , Kamigaki Yumiko , Kanoh Megumi , Takada Atsushi , Okamoto Yoshihisa 
Published: April 2009

AbstractThe reactions of the 3‐substituted 4‐amino‐8‐ethoxycarbonyl[5,1‐c][1,2,4]triazines 1 and 2 with o‐amino‐phenol hydrochloride gave the pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6‐b][1,5]benzoxazepines 5 and 8. The alkylation of 5 with methyl iodide and isopropyl iodide afforded the 6‐alkoxylpyrazolo[1′,5′:3,4][1,2,4]triazino‐[5,6‐b][1,5]benzoxazepines 6a and 6b, respectively. Refluxing of 5, 6a, 6b and 8 in hydrochloric acid/acetic acid resulted in ring transformation to produce the spiro[benzoxazole‐2′(3′H),4(1H)pyrazolo[5,1‐c][1,2,4]‐triazines] 7a, 7b and 9. The screening data of the above compounds was described.
Conjugated azoalkenes. Part V. Facile synthesis of new 1‐aroylamino‐3‐sulfonylpyrroles by reaction of aroylazoalkenes with 1,3‐ketosulfones
Authors: Attanasi Orazio A. , Grossi Mario , Serra‐Zanetti Franco 
Published: April 2009

AbstractThe easy one‐pot synthesis of the interesting 1‐aroylamino‐3‐sulfonylpyrroles by reaction of some aroylazo‐alkenes with 1,3‐ketosulfones is reported.
Derivatives of 3,4‐dihydro‐β‐carboline‐3‐carboxylic acid from c‐terminal tryptophan‐containing peptides. Synthesis and properties
Authors: Letellier Sabine , Fleury Bernard , Torreilles Jean , Previero Aldo 
Published: April 2009

AbstractC‐Terminal tryptophan containing peptides have been converted into 1‐peptidyl‐3,4‐dihydro‐β‐carboline‐3‐carboxylic acids by acid catalyzed isomerization of their azlactone derivatives. The main properties of these abnormal peptides are a strong absorption around 360 nm an intense yellow fluorescence and ability to generate reactive carbanions when dissolved in basic media. This tryptophan conversion takes place with high yield and is of general applicability.
On 6‐(thenoyl)‐7,8‐dichloro‐4‐oxo‐4H‐1‐benzopyran‐2‐carboxylic acid
Authors: Montanari Paola , Da Re Paolo , Valenti Piero 
Published: April 2009

AbstractThe annulation of the oxyacetic chain of thienylic acid into a γ‐pyrone ring is described. The resulting 6‐(2‐thenoyl)‐7,8‐dichloro‐4‐oxo‐4H‐1‐benzopyran‐2‐carboxylic acid retains almost 80% of the diuretic activity of the parent compound.
A simple synthesis of 5‐methoxyindole and 5‐methoxy‐2‐oxindole
Authors: Sakamoto Takeshi , Hosoda Isao , Kikugawa Yasuo 
Published: April 2009

Abstract1‐Methoxy‐ and 1‐hydroxy‐2‐oxindoles rearranged in acidic solution to 5‐substituted 2‐aminophenylacetic acid derivatives which were cyclized to the corresponding 2‐oxindoles with heating. The synthesis of 5‐methoxyindole from 5‐methoxy‐2‐oxindole was also described.
Bridged cyanine dyes. Part 1. 1‐(N‐methyl‐4‐pyridinio)‐3‐(N‐methylpyridylene)cyclopenta‐1,4‐dienes
Authors: Katritzky Alan R. , Fan Wei‐Qiang , Li Qiao‐Ling 
Published: April 2009

Abstract1,3‐Bis(N‐methyl‐4‐pyridinio)propane is condensed with a series of α‐diketones to form deep red monocyanine dyes 8. In strongly acidic solutions C‐protonation occurs at the central carbon atom. A similar condensation with α‐ketoesters yields zwitterionic cyanines 12 with extinction coefficients exceeding 105.
Bridged cyanine dyes. Part 2. 1‐(N‐methyl‐2‐benzothiazolylinio)‐3‐(N‐methyl‐2‐benzothiazolylene) and 1‐(N‐methyl‐4‐pyridinio)‐3‐(N‐methyl‐4‐pyridylene)cyclopenta‐1,4‐dienes with fused rings
Authors: Katritzky Alan R. , Liang De‐Sheng , Fan Wei‐Qiang 
Published: April 2009

Abstract1,3‐Bis(N‐methyl‐4‐pyridyl)‐ and 1,3‐bis(N‐methyl‐2‐benzothiazolyl)‐propane diiodides react with 1,2‐cyclohexanedione, tetrachloro‐1,2‐ and ‐1,4‐benzoquinone, 2,3‐dichloronaphthoquinone, 3,4‐dichloromaleimide and 2,3‐dichloroquinoxaline to give novel fused ring bridged cyanine dyes.
A convenient synthesis of 1,3,6‐dioxazocine, 1,3,7‐dioxazonine, 1,3,8‐dioxazecine and 1,3‐dioxa‐6,10‐diazadodecane
Authors: Krakowiak Krzysztof E. , Kotelko Barbara , Bradshaw Jerald S. , Dalley N. Kent 
Published: April 2009

AbstractA series of perhydro heterocycles of eight to ten ring members containing one nitrogen and two oxygen atoms has been prepared. These include four 1,3,6‐dioxazocines, and 1,3,7‐dioxazonine and one 1,3,8‐dioxazecine. A twelve‐membered ring containing two oxygen and two nitrogen atoms was also prepared. An X‐ray structure of one of the 1,3,6‐dioxazocines,5, was determined. This compound crystallized in the orthorhomic space group Pccn with a = 25.922(15)Å, b = 12.150(4)Å and C = 9.342(4)Å. Two of the 1,3,6‐dioxazocines have the benzylidine acetal structure which will hydrolyze to give benzaldehyde.
Selective α‐cleavage cycloaddition of oxiranes with heterocumulenes catalyzed by tetraphenylstibonium iodide
Authors: Fujiwara Masahiro , Baba Akio , Matsuda Haruo 
Published: April 2009

AbstractA catalytic amount of tetraphenylstibonium iodide (1) promoted unusual cycloadditions of oxiranes with isocyanates or carbodiimides, forming 3,4‐disubstituted oxazolidin‐2‐ones 2 and oxazolidin‐2‐imines 4 under very mild conditions, respectively. In particular, carbodiimides gave 4 exclusively. Either oxazolidine, 3,4‐disubstituted or 3,5‐disubstituted ones could be obtained independently from the same reactants by the compensatable use of 1 and organotin iodide‐Lewis base complexes as catalysts.
The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 1. Thieno[3′,2′:4,5]thieno[2,3‐c]quinoline and thieno[2′,3′:4,5]thieno[2,3‐c]quinoline
Authors: Castle Steven L. , Luo Jiann‐Kuan , Kudo Hirotaka , Castle Raymond N. , Lee Milton L. 
Published: April 2009

AbstractThe synthesis of two previously unknown heterocyclic ring systems, namely, thieno[3′,2′:4,5]thieno[2,3‐c]‐quinoline and thieno[2′,3′:4,5]thieno[2,3‐c]quinoline is reported. These two novel ring systems were assembled by photocyclization of the appropriate anilides.
Condensation of 2H‐indazole‐4,7‐dione derivatives with 2‐aminophenol derivatives
Authors: Nan'ya Seiko , Katsuraya Kaname , Itamoto Yoshie , Maekawa Eturǒ , Ueno Yoshio 
Published: April 2009

AbstractA new type of 9‐substituted‐5‐methyl‐2‐phenyl‐4H‐pyrazolophenoxazin‐4‐one derivatives was prepared by the condensation of 5‐methyl‐ and 6‐methyl‐2‐phenyl‐2H‐indazole‐4,7‐diones with 4‐substituted‐2‐aminophenols in pyridine. Relative reactivity of 2‐aminophenol derivatives in the condensation was studied.
A facile synthesis of substituted 4,5,6,7‐tetrahydropyrazolo[3,4‐d]‐pyrimidine and 1,2,3,4‐tetrahydropyrazolo[1,5‐a]triazine derivatives
Authors: Vishwakarma J. N. , Mofizuddin M. , Ila H. , Junjappa H. 
Published: April 2009

AbstractCyclocondensation of 3(5)‐alkylamino‐ and 3(5‐arylaminopyrazoles 1a‐c and 1d‐e with formaldehyde and primary amines affords novel tetrahydropyrazolo[3,4‐d]pyrimidines 2 and tetrahydropyrazolo[1,5‐a]triazine derivatives 3 respectivley in good yields.