bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ring opening reactions of 6H‐anthra[1,9‐cd]isoxazol‐6‐ones and related compounds
Authors: Sutter P. , Weis C. D. 
Published: March 2009

AbstractNucleophilic attack of anthra[1,9‐cd]isoxazol‐6‐ones, and of anthra[1,9‐cd:5,10‐c'd']isoxazole by various sulfoxides, triphenyl phosphine, and aliphatic or aromatic phosphites proceeded with cleavage of the nitrogenoxygen bond of the isoxazole ring. This method provided ready access to substituted anthraquinones bearing sulfoximido‐, triphenylphosphazo‐, and dialkyl(aryl)phosphoramidic groups attached to the 1‐ and the 1,5‐positions of the anthraquinone system. The structures of the newly synthesized anthraquinone derivatives were supported by analytical and spectral data. l‐S,S‐dimethyl‐N‐(5‐benzamidoanthraquinon‐1‐yl)‐sulfoximide yielded in 90% sulfuric acid the l‐amino‐5‐sulfoximido anthraquinone without hydrolyzing the sulfoximido group.
The 1‐alkoxy‐6‐nitro‐1,2,3‐benzotriazole system
Authors: Jung P. , Seybold P. G. , Servé M. P. 
Published: March 2009

AbstractThe 1‐alkoxy‐6‐nitro‐1,2,3‐benzotriazole system has been synthesized and characterized via its physical and chemical properties. INDO/molecular orbital calculations provide a good account of the major bands in its ultraviolet absorption spectrum.
N‐polyazolylmethanes. 1. Synthesis and nmr study of N,N′‐diazolylmethanes
Authors: Juliá Sebastian , Sala Pilar , Del Mazo José , Sancho Manuel , Ochoa Carmen , Elguero JosÉ , Fayet Jean‐Pierre , Vertut Marie‐Claire 
Published: March 2009

AbstractThirteen N,N‐diazolylmethanes, including derivatives of pyrazole, imidazole, 1,2,4‐triazole, benzimidazole and indazole were prepared by reaction of azoles with methylene chloride under phase transfer catalysis conditions. The relative amounts of isomeric mixtures obtained with ‘asymmetric’ azoles or with equimolar mixtures of azoles are compared with literature results on monoalkylation of azoles. Proton and carbon‐13 nmr spectra of the N,N'‐diazolylmethanes are discussed.
Synthesis of esters of 4‐hydroxy‐5‐phosphinyl‐2‐imidazolidinone
Authors: Mikroyannidis John A. , Tsolis Alexandros K. 
Published: March 2009

AbstractThe esters of 4‐hydroxy‐5‐phosphinyl‐2‐imidazolidinone were prepared by reaction of urea with the esters of 2‐hydroxy‐2‐phosphinylethanal in acidic medium. The ir, 1H nmr and 31P nmr spectral data of the products are reported. All the isolated products had cis configuration. The stereochemistry of their formation is discussed.
A reliable synthesis of 1,1‐dimethylpyrazolium 5‐oxides
Authors: Ellis Jerry W. , Keiter Ellen A. , Keiter Richard L. , Li Tso‐Ping , Uptmor Robert A. 
Published: March 2009

AbstractReliable syntheses of compounds having the novel 1,1‐dimethylpyrazolium 5‐oxide ring system are reported. The method involves treating the dimethylhydrazone of a β‐ketoester with a small amount of concentrated sulfuric acid or other catalyst and heating under reduced pressure for 1–24 hours. In this manner two new members of the series have been prepared and characterized.
Diazotization of a 2‐amino‐1,3‐selenazole
Authors: Archer Sydney , McGarry Ruthann 
Published: March 2009

AbstractDiazotization of 5‐(acetoxyethyl)‐2‐amino‐4‐methylselenazole with nitrosoborofluoride in the presence of sodium fluoride in fluoboric acid solution furnishes 5‐(acetoxyethyl)‐2‐fluoro‐4‐methylselenazole and the corresponding 2‐hydroxy compound. Despite low yields, this was the first time that a Sandmeyer‐Schiemann reaction has been carried out successfully with 2‐aminoselenazoles.
Some reactions of 1‐methyl‐1,2,3,4‐tetrahydropyridine with organic azides. Synthesis of 1‐methylpiperidylidene‐2‐sulfon(cyan)amides
Authors: Warren B. K. , Knaus E. E. 
Published: March 2009

AbstractThe 1,3‐dipolarcycloaddition reaction of 1‐methyl‐1,2,3,4‐tetrahydropyridine (1) with organic azides 2 affords 1‐methylpiperidylidene‐2‐sulfon(cyan)amides 4 in high yield. The reaction proceeds via a 2,3,4,9‐tetrazabicyclo[4.3.0]non‐3‐ene intermediate. Acid hydrolysis of 4d gives rise to 1‐methyl‐2‐piperidone.
Synthesis of potential antineoplastic agents. XXVII. (Reissert compound studies. XLIV.). The ellipticine reissert compound as an intermediate in the syntheses of ellipticine analogs
Authors: Popp Frank D. , Veeraraghavan Seshadri 
Published: March 2009

AbstractEllipticine and a number of ellipticine analogs were converted to Reissert compounds. Alkylation of the 6‐benzylellipticine Reissert compound gave a series of 1‐substituted‐6‐benzylellipticines. 1‐Cyanoellipticine, obtained through the Reissert compound, was hydrolyzed to ellipticine‐1‐carboxamide hydrochloride which was active against P388 lymphocytic leukemia. Other aspects of the chemistry of the ellipticine Reissert compound are presented.
Reaction of N‐(2‐pyridylmethyl)‐3,5‐dimethylbenzamide and N‐(3‐pyridylmethyl)‐3,5‐dimethylbenzamide N‐oxides with acetic anhydride
Authors: Braña Miguel F. , Rodriguez María Luz López 
Published: March 2009

AbstractAs a continuation of our work on the reaction of N‐pyridylmethyl‐3,5‐dimethylbenzamide N‐oxides with acetic anhydride, we now report a study of the reaction of N‐(2‐pyridylmethyl)‐3,5‐dimethylbenzam.de N‐oxide (5) and N‐(3‐pyridylmethyl)‐3,5‐dimethylbenzamide N‐oxide (6) with acetic anhydride. Compound 5 gave N,N′‐di(3,5.dimethylbenzoyl)‐1,2‐di(2.pyridyl)ethenediamine (7) and 3,5‐dimethylbenzamtde (8). Compound 6 afforded three products formulated as 2‐acetoxy‐3‐(3,5‐dimethylbenzoylaminomethyl)pyridine (12), 3‐(3,5‐dimethylbenzoylaminomethyl)‐2‐pyridone (13) and 5‐(3,5‐dimethylbenzoylaminomethyl)‐2‐pyridone (14). Analytical and spectral data are presented which support the structures proposed.
Vierring‐synthesen durch [3 + 1]‐cycloaddition . Synthese von 3‐imino‐azetidinen aus azomethin‐yliden und isonitrilen
Authors: Burger Klaus , Marschke Gregor , Manz Friedrich 
Published: March 2009

AbstractAzomethine ylide 3, generated by thermolysis of 3,4‐diphenyl‐Δ1‐1,2,3‐triazoline‐5,5‐dimethyldicarboxylate 1, can be trapped by isonitriles to give 3‐imino‐1,4‐diphenylazetidine‐2,2‐dimethyldicarboxylates 5. The IR, 1H‐NMR, 13C‐NMR and mass spectral data of the new compounds are discussed.
The cyclization of N,N′‐bis[2‐(dialkoxy)ethyl]‐p‐xylene‐α,α′‐diamine dihydrochloride to pyrido[3,4‐g]isoquinoline and 3,8‐phenanthroline
Authors: Schwan Thomas J. , Miles Nelson J. 
Published: March 2009

AbstractThe ring closure of N,N′‐bis[2‐(dialkoxy)ethyl]‐p‐xylene‐α,α′‐diamine dihydrochloride in fuming sulfuric acid has been investigated and the cyclization products have been identified as the linear pyrido[3,4‐g]isoquinoline as well as the previously reported angular 3,8‐phenanthroline.
Carbon‐13 NMR characterisation of carboxyl derivatives of 1‐ureidopyrroles
Authors: Lamartina Liliana , Migliara Onofrio , Sprio Vincenzo 
Published: March 2009

Abstract1‐Ureido‐5‐methyl‐2,3‐dicarbethoxypyrrole under acidic conditions afforded different partially hydrolyzed or decarboxylated products. It has been possible to characterize two isomeric monoethyl esters of dicarboxylic acids of 1‐ureidopyrroles by proton gated decoupled carbon‐13 nmr spectra on the basis of multiplicities of the carbonyl carbons resonances.
Chemistry of the phenoxathiins and isosterically related heterocycles. XXIII . 1‐azathianthrene: First reported synthesis of a monoazathianthrene and the investigation of the 13C‐NMR spectrum using two‐dimensional NMR techniques
Authors: Puig‐Torres Salvador , Martin Gary E. , Ford Joseph J. , Willcott M. Robert , Smith Keith 
Published: March 2009

AbstractThe reaction of the dianion of 3‐mercaptopyridin‐2(1H)‐thione with 2‐chloronitrobenzene in N,N‐dimethylformamide leads to the formation of 1‐azathianthrene, the first reported mono‐aza analog of the thianthrene ring system. A partial assignment of the 13C‐nmr spectrum of the title compound is reported, the assignment based on chemical shift arguments, spin‐lattice (T1) relaxation times and 1H‐13C spin coupling constants. Amplitude modulated two‐dimensional Fourier transform (AM2DFT) techniques were employed for the acquisition of the heteronuclear spin‐coupling constants.
Chemistry of the phenoxathiins and isosterically related heterocycles. XXIV . Synthesis of characterization by 13C‐NMR spectroscopy of isomeric benzoxathiinopyridazinones: 1‐Oxo‐1,2‐dihydro‐2,3‐diazaphenoxathiin and 4‐Oxo‐3,4‐dihydro‐diazaphenoxathiin. The first observation of a smiles rearrangement involving divalent sulfur during the synthesis of an azaphenoxathiin
Authors: Womack Charles H. , Martin Linda M. , Martin Gary E. , Smith Keith 
Published: March 2009

AbstractCondensation of the disodium salt of o‐mercaptophenol with 4,5‐dichloro‐6(1H)‐pyridazinone in N,N‐dimethylformamide has been observed to lead to the formation of both possible isomeric benzoxathiinopyridazinones. The separation of these isomers, 1‐oxo‐1,2‐dihydro‐2,3‐diazaphenoxathiin and 4‐oxo‐3,4‐di‐hydro‐2,3‐diazaphenoxathiin and their characterization by 13C‐nmr spectroscopy is described. Mechanisms to account for the formation of both isomers are discussed, the most probable mechanism involving a Smiles rearrangement of the phenolate sulfide intermediate formed by the initial displacement of the 4‐chloro substituent, providing a specie analogous to a β‐halovinylogous ketone.
Regioselective aziridine ring expansions
Authors: Clough Stuart C. , Solomon Robert , Crews Elain , Jaques Larry , Johnson Ashby , Forehand John 
Published: March 2009

Abstract1‐Phenylmethyl‐2‐hydroxymethylaziridine (1) undergoes regioselective reactions with carbon disulfide to form thiazolidinethiones. Deuterium labeling experiments suggest that the reaction proceeds exclusively via aziridinium ring expansion. The regiospecificity appears to be electronically controlled.
Pyrrolo[1,4]benzodiazepines. III. synthesis of 5,11‐dioxo‐1,10,11,11a‐tetrahydro‐2‐vinyl‐5H‐pyrrolo[2,1‐c][1,4]benzodiazepine
Authors: Massa S. , De Martino G. , Corelli F. 
Published: March 2009

AbstractSome pyrrolo[2,1‐c][1,4]benzodiazepines having a chain of two carbon atoms, as it is found in antibiotic tomaymycin, were prepared. The first reaction was the C‐acetylation of 1‐(2‐nitrobenzoyl)‐Δ4‐pyrroline‐2,2‐dicarboxylic acid diethyl ester; successive transformations of the acetyl group and cyclization gave the proposed structures.
Degradation products of 3‐phenylmethylpyrido[3,4‐e]‐1,2,4‐triazine
Authors: Michels Julian G. 
Published: March 2009

AbstractThe thermal degradation of 3‐phenylmethylpyrido[3,4‐e]‐1,2,4‐triazine (I) leads to a large number of compounds. The isolation and identification of two of these is described.
A facile preparation of 4‐(1‐Acetyl‐4(1H)‐pyridylidene)‐2‐oxazohn‐5‐ones
Authors: Hirota Kazuhiro , Shimamura Michiya , Ikeda Mikiko , Ohmori Shinji 
Published: March 2009

Abstract4‐(1‐Acetyl‐4(1H)‐pyridylidene)‐2‐oxazolin‐5‐ones were prepared by the reaction of acylglycines with pyridine and acetic anhydride under oxygen. Acidic and alkaline hydrolysis of 2‐oxazolin‐5‐ones provided oxazole derivatives, pyridine derivatives, and carboxylic acids.
Phase transfer catalysis in N‐alkylations of the pharmaceutical intermediates 5H‐dibenz[b,f]azepine and 5H‐10,11‐dihydrodibenz[b,f]azepine
Authors: Gozlan Igal , Halpern Marc , Rabinovitz Mordecai , Avnir David , Ladkani David 
Published: March 2009

AbstractThe two title compounds were alkylated under very mild phase‐transfer‐catalysis conditions. Differences in reactivities of the two heterocyclic nucleophiles, and in the reactivities of various alkyl halides are discussed.
Acid catalyzed chlorination of pyrrole with N‐chloroacetanilide
Authors: de Rosa Michael 
Published: March 2009

AbstractThe chlorination of pyrrole with N‐chloroacetanilide was catalyzed by acetic acid. Transfer of Cl+ occurred directly to the α and β positions of pyrrole and a mixture of 2‐chloro‐, 3‐chloro‐ and 2,5,‐dichloropyrrole was formed. The α↗β ratio was 10:1 under competitive conditions.
Pyrrolothienopyrazines: Synthèse de la pyrrolo[1,2‐a]thieno[3,2‐e]pyrazine et de la pyrrolo[1,2‐a]thieno[2,3‐e]pyrazine
Authors: Rault Sylvain , Effi Yamien , De Sevricourt Michel Cugnon , Lancelot Jean‐Charles , Robba Max 
Published: March 2009

AbstractLa synthèsis de la pyrrolo[1,2‐a]thiéno[3,2‐e]pyrazine et de la pyrrolo[1,2‐a]thiéno[2,3‐e]pyrazine est étudiée. Elle est réalisable par cyclisation intramoléculaire cyclization des (pyrrol‐1)‐2(et‐3) ‐thienylamines‐3 (et‐2) qui peuvent ě obtainus par hydrolyse des carbamates ou par scission des urěes correspondantes. une seconde voice de synthése original autorisant de meilleurs résultants a été développée avec mise en oeuvre d'un réarrangement de Curtius qui oppose un groupement azoture à un way groupement aldéhyde. La synthése des azotures de (formyl‐2‐1‐pyrrolyl)‐2‐(et‐3)‐thénoyle‐3(et‐2) est décrite.
Studies on pyrazines. 9 . The facile synthesis of pyrazine 1‐oxides substituted at C‐2 with cyano, methoxycarbonyl and carboxy groups
Authors: Sato Nobuhiro 
Published: March 2009

AbstractThe peroxysulfuric acid oxidation of 2‐cyanopyrazine (1) gave its 1‐oxide 3 (18% yield) and pyrazinecarb‐oxamide (8% yield), while that of methyl pyrazinecarboxylate (2) provided the 1‐ and 4‐oxides in 15 and 7% yields, respectively. On the other hand, pyrazinecarboxylic acid 1‐oxide (7) was prepared by condensation of 2‐methylpyrazine 1‐oxide (8) with benzaldehyde followed by oxidative cleavage (47% overall yield).
Preparation of 7‐substituted pyrrolo [2,3‐d] pyrimidines and 9‐substituted purines as potential antiparasitic agents
Authors: LaMontagne Maurice P. , Smith David C. , Wu Geng‐Shuen 
Published: March 2009

AbstractA series of six 7‐substituted pyrrolo [2, 3‐d] pyrimidines and two 9‐substituted purines were prepared and evaluated for potential antiparasitic activity. All were inactive against P. berghei in mice. Six of the target compounds were also evaluated for antitrypanosomal activity against T. rhodesiense in mice. All six compounds were also inactive in this screen.
Benzoxazol‐2 (3H)‐one and 1,3,4‐oxadiazol‐2(3H) ‐one derivatives from substituted enaminones and ketoenamines
Authors: Forchiassin M. , Pitacco G. , Risaliti A. , Russo C. , Valentin E. 
Published: March 2009

AbstractEnaminones and ketoenamines bearing a hydrazine type substituent undergo side chain thermal cyclization, the former into benzoxazol‐2 (3H)‐one derivatives and the latter into 1, 3, 4‐oxadiazol‐2 (3H)‐one derivatives. Factors affecting such reactions are discussed.
Synthesis and carbon‐13 NMR study of 2‐benzyl, 2‐methyl, 2‐aryloctahydropyrrolo [3,4‐c] pyrroles and the 1,2,3,5‐tetrahydropyrrolo [3,4‐c] pyrrole ring system
Authors: Ohnmacht Cyrus J. , Draper Clyde W. , Dedinas Robert F. , Loftus Philip , Wong J. J. 
Published: March 2009

Abstract2‐Benzyl, 2‐phenyl, 2‐ (3‐methoxyphenyl) and 2‐(3‐trifluoromethylphenyl) octahydropyrrolo[3,4‐c]pyrrole (9a, 9b, 9c, and 9d, respectively) were prepared in five steps from 1‐benzylpyrrole‐3,4‐dicarboxylic acid (2). 2‐Methyloctahydropyrrolo [3,4‐c]pyrrole (9′a) was prepared analogously in six steps from 1‐methylpyrrole‐3,4‐dicarboxylic acid (3). Diborane reduction of 1‐benzyl‐N‐methyl‐1H‐pyrrole‐3,4‐dicarboximide (7′a) and 1, N‐dibenzyl‐1H‐pyrrole‐3,4‐dicarboximide (7a) gave 5‐benzyl‐2‐methyl and 2, 5‐dibenzyl‐1,2,3,5‐tetrahydropyrrolo [3,4‐c]pyrrole (19′ and 19, respectively); the first reported members of the 1,2,3,5‐tetrahydropyrrolo[3,4‐c]pyrrole ring system. A detailed study of the carbon‐13 nmr shifts permitted a complete assignment for all compounds. Mono and disubstituted products produce a systematic effect on the shifts for the bicyclic ring systems which can be readily interpreted in terms of substituent chemical shifts. The effect of protonation at nitrogen is also shown to produce a series of well defined chemical shifts for the octahydropyrrolo [3,4‐c] pyrrole ring system.
Synthesis of some pyridylamino‐1,4‐disubstituted phthalazines
Authors: Bautista Dorothy V. , Bullock Graham , Hartstock Frederick W. , Thompson Laurence K. 
Published: March 2009

AbstractTwo general procedures involving the condensation of phthalonitrile or 1,3‐diiminoisoindoline with various aminopicolines, followed by ring expansion with hydrazine to the corresponding phthalazine are described. Syntheses are reported of 1, 4‐di(3′‐methyl‐2′‐pyridyl) aminophthalazine, 1,4‐di(5′‐methyl‐2′‐pyridyl)aminophthalazine, and 1,4‐di(4′, 6′‐dimethyl‐2′‐pyridyl)aminophthalazine.
Reaction of tetrachloropyrazine with active methylene compounds
Authors: Tong Y. C. , Kerlinger H. O. 
Published: March 2009

AbstractWhen tetrachloropyrazine was allowed to react with the anions formed from diethyl malonate and malonitrile, the normal alkylation took place. When the anions from ethyl acetoacetate and N,N‐diethylacetoacetamide were used, alkylation was followed by enolization and ring formation to give furo [2,3‐b] pyrazines. The structure proof and reaction of the furo [2,3‐b] pyrazines are discussed.
Identification of the nitrosation reaction products of alkyl esters of 1,2‐benzisoxazole‐3‐acetic acid by chemical and crystallographic methods
Authors: Giannella Mario , Gualtieri Fulvio , Fedeli Walter , Cerrini Silvio , Gavuzzo Enrico 
Published: March 2009

AbstractThe reaction between methyl or ethyl esters of 1, 2‐benzisoxazole‐3‐acetic acid and iso‐amyl nitrite is reported. The main product is identified as 4‐(2′‐hydroxyphenyl)furazan‐3‐carboxylic acid (4) by chemical and X‐ray crystal structure analyses. The synthesis of esters of E‐ and Z‐α‐(hydroxyimino)‐1, 2‐benzisoxazole‐3‐acetic acid is also reported.
A simple synthesis of 5‐fluorouracil by a novel ring transformation reaction
Authors: Chung Won Keun , Chung Jin Hyun , Watanabe Kyoichi A. 
Published: March 2009

AbstractA very simple method for the preparation of 5‐fluorouracil (1) from 1,3‐dimethyl‐5‐azauracil (2) by a novel ring transformation reaction is reported.
Synthesis of 6,7‐methylenedioxy‐3,4‐dihydro‐1‐methylbenzothieno[2,3‐c]pyridine
Authors: Ruffin L. D. , Bowlus S. B. 
Published: March 2009

AbstractSynthesis of the title compound, a potential inhibitor of mouse brain monoamine oxidase, is described. The preparation proceeds in eight steps from 1,3‐benzodioxole in 1.9% overall yield. The novel hydrogenolysis of an aryl thiocyanate to the aryl methyl sulfide is reported.
A convenient synthesis of 1‐methyl‐4‐oxopiṕecolic acid methyl ester
Authors: Essawi M. Y. , Portoghese P. S. 
Published: March 2009

AbstractAn efficient and convenient synthesis of the title compond 1 is described. The approach to the synthesis is based on hydride reduction of the 4‐methoxypyridinium salt 5, followed by acid hydrolysis of the resulting vinyl ether intermediate 6.
Preparation of zwitterionic electron acceptors and donors
Authors: Willner Itamar , Ford William E. 
Published: March 2009

AbstractThe reactions of 4, 4'‐bipyridine and nicotinamide with 1, 3‐propane sultone yields zwitterionic electron acceptors. Reaction of dimethylaminoethyl ferrocene with 1, 3‐propane sultone yields a zwitterionic ferrocene electron donor. The electron acceptors and donor are reduced and oxidized to the respective radical anions and ferrocenyl cation. Dipropyl‐4, 4'‐bipyridinium disulfonate and the ferrocene derivative quench the excited Ru(bipy)32+.
Reactions of 2‐hydroxybenzonitrile with isocyanates
Authors: Petridou‐Fischer J. , Papadopoulos E. P. 
Published: March 2009

AbstractTriethylamine catalyzes the reaction of 2‐hydroxybenzonitrile (1) with aryl isocyanates to form the corresponding carbamates 2a‐c, as well as the cyclization of the latter compounds to either 4[N‐(N‐arylcarbamoyl)‐imino]‐3‐aryl‐2H‐1,3‐benzoxazin‐2‐ones 4a‐c, or 4‐arylamino‐2H‐1,3‐benzoxazin‐2‐ones 7a‐c, depending on the reaction temperature. Under analogous conditions, the carbamates obtained from 1 and 2‐chloroethyl isocyanate, 3‐chloropropyl isocyanate and ethyl isocyanatoacetate undergo a double cyclization yielding imidazo‐ and pyrimido[1,2‐c|1,3]benzoxazinones 13a,b,17. Upon heating in phenyl ether, compounds 7a‐c, rearrange to 2‐(2‐hydroxyphenyl)‐4(3H)‐quinazolinones 10a‐c.
Syntheses de nouveaux heterocycles pyrroliques: Des thiepino[4,5‐c]‐ et [4,5‐b]pyrroles
Authors: Duflos Jack , Dupas Georges , Quéguiner Guy 
Published: March 2009

AbstractLa réaction des diformyl‐3,4 et −2,3 N méthyl pyrroles (1) et (2) avec des sulfones donne respectivement les dioxydes‐6,6 thiépino[4,5‐c]‐ et [4,5‐6]pyrroles. Nos essais pour condenser les sulfures avec 1 ont conduit au cycle thiépino[4,5‐c]pyrrolique, mais seulement à une benzoannélation avec 2.
Synthesis of a novel indolobenzodiazepine
Authors: Peet Norton P. , Sunder Shyam 
Published: March 2009

Abstract2‐[(5‐Methyl‐1,3,4‐oxadiazol‐2‐yl)methyl]benzenamine (15) was prepared in four steps from o‐nitrophenyl‐acetic acid, and treated with triethyl orthoformate in an attempt to prepare an oxadiazolobenzodiazepine. However, the resulting product was 13‐(5‐methyl‐1,3,4‐oxadiazol‐2‐yl)‐5H‐indolo[2,1‐b][1,3]benzodiazepine monohydrate (16). Indolobenzodiazepine 16 is the first reported member of a novel ring system. Interesting features of the synthesis of 16 are discussed, including the mechanism of formation from 15.
New oxidative cyclizations of 1,3,4,6‐tetraketones. Synthesis and structure of (Z)‐2‐acyl‐5‐alkyl(aryl)‐1,4‐dioxaspiro[2.4]hept‐5‐en‐7‐ones
Authors: Poje M. , Sikirica M. , Vicković I. 
Published: March 2009

AbstractIodosobenzene diacetate oxidation of 1,3,4,6‐tetraketones 1a‐c yielded (Z)‐2‐acyl‐5‐alkyl(aryl)‐1,4‐dioxa‐spiro[2.4]hept‐5‐en‐7‐ones (4a‐c) in addition to 2‐acyl‐6‐alkyl(aryl)‐3‐hydroxy‐4‐pyrones (3a‐c). The structure of new spiro‐heterocycles 4 was inferred from chemical and spectroscopic data, and the stereochemistry was fully defined by a single‐crystal X‐ray analysis. Alternative cyclization pathways can be rationalized as proceeding through carbocation intermediates derived from both forms of the ring‐chain tautomerism of 1,3,4,6‐tetraketones 1.
Synthesis of new heterocycles. 3,4‐dihydropyrano[2,3,4‐hi]indolizine and derivatives
Authors: Sliwa Henri , Blondeau Dominique , Rydzkowski Richard 
Published: March 2009

AbstractInteraction of the lithium derivative of 2,3‐dihydro‐4H‐pyrano[3,2‐b]pyridine with the diethyl acetal of bromoacetaldehyde, followed by hydrolysis and subsequent ring closure afforded the novel heterocycle 3,4‐dihydropyrano[2,3,4‐hi]indolizine which was inacessible by the Tschitschibabin method. However, the 2‐phenyl derivative was easily prepared by the Tschitschibabin method.
Synthesis and spectral behavior of 6‐phenyl‐5,6,7,8‐tetrahydro‐4H‐1,3,6‐dioxazocines using NMR
Authors: Nishiyama Tomihiro , Iwasaki Yoshiaki , Yamada Fukiko 
Published: March 2009

AbstractHeterocyclic compounds of four 6‐phenyl‐5,6,7,8‐tetrahydro‐4H‐1,3,6‐dioxazocines have been synthesized by condensation of the corresponding N,N‐bis(2‐hydroxyethyl)‐ or N,N‐bis(2‐hydroxypropyl)anilines with aldehyde or ketone in the presence of acid. The pmr and cmr spectra of these compounds were recorded to determine their stereochemical structures. On the basis of the chemical shifts due to the γ‐effects, the stereochemical structures are discussed.
Synthesis of ketobemidone precursors via phase‐transfer catalysis
Authors: Cammack Thomas , Reeves Perry C. 
Published: March 2009

AbstractHydrochloride salts of N‐substituted‐bis‐(2‐chloroethyl)amines can be condensed with m‐methoxyphenyl‐acetonitrile or 1‐phenyl‐2‐alkanones under phase‐transfer conditions to yield precursors of the powerful analgesic compounds ‐ the ketobemidones.
Furopyridines. IV. Unexpected dimerization of 5‐methyl‐4,5,6,7‐tetrahydrofuro[3,2‐c]‐ and 6‐methyl‐4,5,6,7‐tetrahydrofuro[2,3‐c]pyridine by acidic hydrolysis
Authors: Shiotani Shunsaku , Morita Hiroyuki , Inoue Masatoshi , Ishida Toshimasa , Doi Mitsunobu , In Yasuko 
Published: March 2009

AbstractReaction of 5‐methyl‐4,5,6,7‐tetrahydrofuro[3,2‐c]‐ (1) and 6‐methyl‐4,5,6,7‐tetrahydrofuro[2,3‐c]pyridine (2) with hydrochloric acid gave novel dimerized compounds 3a‐d and 4a‐d, respectively. The structures of 3a, 3b, 4a and 4b were determined by spectroscopic method, and 3c, 3d, 4c and 4d by single crystal X‐ray analysis. The reaction courses for the formation of these compounds are proposed.