bluuebunny/crossref_metadata_2025_split huggingface dataset:
The synthesis of benzofuroquinolines. I. Some benzofuro[2,3‐b]quinoline and benzofuro[3,2‐c]quinoline derivatives
Authors: Kawase Yoshiyuki , Yamaguchi Seiji , Maeda Osamu , Hayashi Akemi , Hayashi Ichihiro , Tabata Kazuko , Kondo Masako 
Published: April 2009

AbstractBenzofuro[2,3‐b]quinoline (Ia) and its 11‐methyl derivative (Ib) were synthesized by demethylcyclization of 3‐(o‐methoxyphenyl)‐1,2‐dihydroquinolin‐2‐ones (VIa,b). Benzofuro[2,3‐b]quinoline‐11‐carboxylic acid (Id) was synthesized by chlorination followed by the action of potassium hydroxide of a lactone (IX) prepared by demethyl‐cyclization of 3‐(o‐methoxyphenyl)‐2‐oxo‐1,2‐dihydroquinoline‐4‐carboxylic acid (VIII). Isomeric benzofuro[3,2‐c]quinoline (Ha) and its 6‐methyl derivative (IIb) were synthesized by demethyl‐cyclization of 3‐(o‐methoxyphenyl)‐1,4‐dihydroquinolin‐4‐ones (XIa,b). Both the methyl derivatives (Ib and IIb) were converted to the carboxylic acids (Id and IId) through condensation with benzaldehyde followed by oxidation. The benzofuroquinolines (Ia,b,d and IIa,b) thus obtained were oxidized to the corresponding N‐oxides (IIIa,b,d and IVa,b).
Bis‐aminoquinolines as potential antimalarial agents and a novel fused ring system, pyrano[3,2‐c:5,6‐c′]diquinoline
Authors: Nasr M. , Burckhalter J. H. 
Published: April 2009

Abstract3,3′(1,3‐Ethyliminodimethylene)bis(4‐hydroxy‐6‐methoxy‐2‐methyl)quinoline (2c) and related compounds were synthesized. 3,3‐Methylenebis(4‐hydroxy‐6‐methoxy‐2‐methyl)quinoline (5) was prepared and upon treatment with phosphorus oxychloride gave 1,13‐dimethyl‐5,9‐dimethoxy‐14H‐pyrano[3,2‐c:5,6‐c′]diquinoIine (6), a novel ring system.
Alcohols and aluminium alkoxides in the presence of raney nickel as alkylating agents. 1. Alkylation of indoles and pyrroles
Authors: Botta M. , De Angelis F. , Nicoletti R. 
Published: April 2009

AbstractIndole and 3‐methylindole are completely converted by alcohols into N‐alkyl or N‐isoalkyl derivatives in the presence of aluminium alkoxides and Raney Nickel; 2‐methylindole gives lower yields. Pyrroles suffer N‐ and C‐alkylation but the initially formed N‐alkylpyrroles are reduced into N‐alkylpyrrolidines in the reaction mixtures.The occurrence of these N‐alkylations is at variance with the C‐alkylation of indoles and pyrroles which takes place by means of alcohols and sodium alkoxides. This suggests that the reaction occurs between the substrate and the reagent both coordinated by aluminium.
Peroxydation du dihydro‐2,3 4H pyranne et du dihydro‐2,3 furanne. Etude de réactivités
Authors: Filliatre C. , Villenave J. J. , Manigand C. 
Published: April 2009

AbstractLa réaction d'un substrat, possédant un atome d'hydrogène labile, avec un hydroperoxyde en presence d'un sel cuivreux permet de synthétiser des peroxydes. L'analyse de ceux obtenus à partir d'hétérocycles oxygénés insaturés montre une réactivité dix fois plus grande pour les hydrogènes allyliques que pour les hydrogènes en α de l'hétéroatome.
Synthesis in the diazasteroid group XI. A convenient route to the 4,8‐diazasteroid system
Authors: Yamazaki Takao , Takahata Hiroki , Matsuura Tomoko , Castle Raymond N. 
Published: April 2009

AbstractThe reaction of 1,6‐naphthyridine 3 with acetic anhydride results in the formation of the 1:1 adduct 4. Upon catalytic hydrogenation followed by acid hydrolysis and esterification, 4 affords 7 as an A‐B steroid ring system synthon in moderate yield. Upon condensation with cyclopentanone and cyclohexanone, 7, gives the 4,8‐diazasteroid system 8 and the D‐homo compound 9, respectively.
Pyrimidones 1. Synthesis of some 1‐substituted‐5‐aryl‐ and (4,5‐diaryl)‐2(1H)pyrimidones
Authors: Coppola Gary M. , Fraser James D. , Hardtmann Goetz E. , Huegi Bruno S. , Kathawala Faizulla G. 
Published: April 2009

AbstractA series of 1‐substituted‐5‐aryl‐2(1H)pyrimidones has been prepared by a method involving condensation of an appropriate N‐substituted urea with either 2‐aryl‐3‐(dimethylamino)‐acroleins or 2‐arylmalondialdehydes. On biological investigation, several compounds exhibited some antiinflammatory activity.
Alkyl‐ and arylthiation of uracil and indole
Authors: Anzai Kentaro 
Published: April 2009

Abstract5‐Alkyl‐ or arylthio‐2,4‐pyrimidinediones, 1–8, were prepared from uracil and alkane‐ or arenesulfenyl chlorides. Indole reacted similarly to give the 2,3‐di‐ and 3‐substituted derivatives, 15–19.
Characterization of blocked nucleosides by mass spectrometry. Benzyl derivatives
Authors: Cory H. T. , Yamaizumi K. , Smith David L. , Knowles D. R. , Broom Arthur D. , Mccloskey James A. 
Published: April 2009

AbstractThe mass spectra of eleven model monobenzylated nucleosides were studied using low and high resolution mass spectrometry. Structural assignments to the major ions were made and several decomposition mechanisms proposed, with the goal of establishing the uses and limitations of mass spectrometry for the characterization of benzylaled nucleosides. Mass spectra generally permit determination of the extent and site of benzylation, with particular regard to base vs. sugar substitution, 0–2′ vs. 0–3′ or 0–5′, and in some cases 0–5′ vs. other isomers.
Synthesis of 6‐phenyl‐5,6,7,8‐tetrahydro‐4H‐1,3,2,6‐dioxathiazocine 2‐oxides
Authors: Nishiyama Tomihiro , Ido Kiyoshi , Yamada Fukiko 
Published: April 2009

AbstractFour 6‐phenyl‐5,6,7,8‐tetrahydro‐4H‐1,3,2,6‐dioxathiazocine 2‐oxides were synthesized by the reaction of the corresponding N,N‐bis(2‐hydroxyethyl)aniline with thionyl chloride in the presence of triethylamine.
Synthesis of 1‐(N‐piperidinoacetyl)‐4‐arylthiosemicarbazides as possible anticonvulsants
Authors: Misra R. S. , Parmar S. S. , Kishore V. , Ali B. , Gupta T. K. 
Published: April 2009

AbstractSeveral 1‐(N‐piperidinoacetyl)‐4‐arylthiosemicarbazides were synthesized from N‐piperidinoacetyl hydrazide, which was obtained by the reaction of hydrazine hydrate with ethyl N‐piperidinoacetate. The anticonvulsant activity of these substituted thiosemicarbazides was reflected by their ability to provide 10–50% protection against pentylenetetrazol‐induced convulsions in mice. All substituted thiosemicarbazides (0.3 mM) inhibited in vitro monoamine oxidase activity of rat brain homogenates and provided 21–86% protection against hypoosmotic hemolysis at a final concentration of 0.1 mM.
Some derivatives of benzoin
Authors: Mendel Arthur , Lillquist Gerald J. 
Published: April 2009

AbstractExtension of the reaction time of benzoin (I) with anthranilamide (II) gave 2,3,5,6‐tetraphenyl‐pyrazine (IV) in addition to the expected benzamide III. Condensation of I with II in the presence of ammonium acetate or ammonium formate yielded IV, and IV with 4‐quinazolinone (VII), respectively. Reaction of I with ammonium acetate only led to IV and 2,3,5,6‐tetraphenylpyrrole (VIII). When I was heated with 2‐aminothiazole, benzil, desoxybenzoin, and VIII were formed. A mechanism has been extended to explain the formation of IV and VIII.
Nitrogen photochemistry. Cocaine and its model compounds
Authors: Singh S. P. , Kaufman Don , Stenberg Virgil I. 
Published: April 2009

AbstractThe ultraviolet irradiation of the π → π* transition of cocaine, p‐anisoyl‐l‐ecognine methyl ester, p‐toluoyl‐l‐ecognine methyl ester benzoyl tropine and benzoylpseudotropine in methanol using a Corex filter produces the corresponding N‐demethylated products. Formaldehyde is quantitatively produced. 1‐Methyl‐3‐piperidyl benzoate and 1‐methyl‐4‐piperidyl benzoate yield benzoic acid under the same conditions but no demethylated products. Phenylacetyl‐l‐ecognine methyl ester gives no demethylation during irradiaiton. The phosphorescence bands of cocaine and its model compound, methyl benzoate, have been shown to be strongly dependent upon solvent polarity suggesting charge transfer in the triplet state.
Derivatives of indole‐3‐oxyacetic acid
Authors: Galun A. , Kampf A. , Markus A. 
Published: April 2009

AbstractThe synthesis of 1‐benzyl‐2‐methyl‐5‐methoxyindole‐3‐oxyacetic acid (11) and of 1‐benzyl‐2‐methylindole‐3‐oxyacetic acid (17) was undertaken in the course of a study aimed at the preparation of potential anti‐inflammatory agents.
Synthesis of some substituted 3‐alkenyl‐1‐phenylpyrazoles
Authors: Deshayes Christian , Gelin Suzanne 
Published: April 2009

AbstractThe regioselective synthesis of new 3‐alkenyl‐1‐phenylpyrazoles 4 from the reaction of phenylhydrazine with 2,3‐dihydro‐4H‐pyran‐4‐ones 1 is described.
5,6‐Dimethylbenz[c]acridine functionalized in the 7‐position
Authors: Cromwell Norman H. , Pokorny David J. , Loerch Robert , Kasperbauer Jan 
Published: April 2009

Abstract5,6‐Dimethylbenz[c]acridines, functionalized in the 7‐position by the carboxy, carbomethoxy, carboxamido, N‐ethylcarboxamido, acetyl, cyano, chloro, methoxy or amino group are reported for the first time. Also various related 5,5‐dimethyl‐5,6‐dihydrobenz[c]acridines including the 7‐carbomethoxy, 6‐hydroxy‐7‐carboxy, 6‐bromo‐7‐carbomethoxy, 6‐methoxy‐7‐carboxy, 6‐methoxy‐7‐carbomethoxy, and 6‐hydroxy‐7‐N‐ethylcarboxamido derivatives which serve as precursors to the completely aromatized 5,6‐dimethylbenz[c]acridines are also reported for the first time.
Synthesis of acetylenic β‐diketones and their conversion into 4H‐pyran‐4‐ones, pyrazoles, and 1‐hydroxy‐4‐pyridones
Authors: El‐Kholy Ibrahim El‐Sayed , Marei Mohamed Gaber , Mishrikey Morcos Michael 
Published: April 2009

AbstractA simple method for the synthesis of acetylenic β‐diketones is described. They can be cyclized to the corresponding 4H‐pyran‐4‐ones with acids. Their reaction with hydrazine hydrate gave pyrazole derivatives isomeric with those obtained from 4H‐pyran‐4‐ones. With hydroxyl‐amine hydrochloride in ethanol, 1‐hydroxy‐4‐pyridones are formed.
Conformation of 7‐chloro‐5‐phenyl‐d5 −3(S)‐methyl‐dihydro‐1,4‐benzodiazepin‐2‐one in solution
Authors: Šunjić V. , Lisini A. , Sega A. , Kovač T. , Kajfež F. , Ruščić B. 
Published: April 2009

Abstract7‐Chloro‐5‐phenyl‐d5‐3(S)‐methyldihydro‐1,4‐benzodiazepin‐2‐one (1a) was synthesized and its conformation in solution determined using a computer assisted LIS‐NMR method. It was found, with Fr(fod)‐d27 as a shift reagent, that a lanthanide coordinates to a carbonyl oxygen at a 2.02 Å distance (bond angle 158.07°, torsional angle 39.53°), while the substrate 1a adopts an expected quasi‐boat conformation with a C(3)‐methyl group exposed in a quasi‐equatorial position.
Steroidal aminothiazoles
Authors: Catsoulacos Panayotis , Kallias Dimitrios 
Published: April 2009

AbstractThe treatment of 16α‐bromo‐17‐ketosteroids and 2‐bromo‐3‐ketosteroids with thiourea in dimethylformamide give the corresponding 2′‐formamidothiazolosteroids.The resulting 2′‐formamidothiazoles were identical with those obtained in a similar reaction from 17β‐bromo‐16α,17α‐oxidoandrostane with thiourea. Hydrolysis of the 2′‐formamido‐thiazolosteroids led to the corresponding 2′‐aminothiazoles, which also resulted from the interaction of bromoketones and thiourea in isopropanol.The title compounds prepared were substantiated by examination of infrared, ultraviolet, mass and nuclear magnetic resonance spectra.
Synthèse de 1H‐pyrazolo[3,4‐b] pyridines et de pyrazolo[1,5‐a] pyrimidines
Authors: Van Haverbeke Y. , Maquestiau A. , Vanden Eynde J. J. 
Published: April 2009

AbstractLa réaction entre une aminopyrazolone et un dérivé β‐dicarbonylé est étudiée. L'orientation de la cyclocondensation dépend de la nature de chacun des précurseurs.
Coumarins via the wittig reaction. Synthesis of methoxsalen‐5‐14C
Authors: Liu Yu‐Ying , Thom Edna , Liebman Arnold A. 
Published: April 2009

AbstractA new and improved synthesis of methoxsalen (3) has been developed for the preparation of specifically carbon‐14 labelled 3. Introduction of the label by a Gattermann reaction on 6‐hydroxy‐7‐methoxycoumaran (1) followed by dehydrogenation provides an intermediate 6 which, on reaction with carbethoxymethylenetriphenylphosphorane (8) and heat inversion, provides the title compound in overall yields of up to 50%. By these procedures, 3 has been prepared 14C labelled at C‐5. Alternatively, 3 may be prepared from 6 and ethyl cyanoacetate in lower overall chemical yield but in potentially higher radiochemical yield if labelling at C‐6 or C‐7 is required since the Wittig process utilizes an excess of phosphorane.
The chemistry of 2H‐3,1‐benzoxazine‐2,4(1H)dione (isatoic anhydride) 4. Synthesis of 2‐imino‐3‐indolinones
Authors: Coppola Gary M. 
Published: April 2009

AbstractThe reaction of isatoic anhydrides with potassium cyanide to form 2‐imino‐3‐indolinones (2) is described. Acidic hydrolysis of 2 furnishes the corresponding isatins.
The chemistry of 2H‐3,1‐benzoxazine‐2,4‐(1H)dione (isatoic anhydride) 5. Synthesis of the [1]benzopyrano[3,2‐c]quinoline ring system
Authors: Coppola Gary M. , Hardtmann Goetz E. 
Published: April 2009

AbstractThe reaction of isatoic anhydrides with the anion derived from ethyl o‐fluorobenzoylacetate to furnish [1]benzopyrano‐[3,2‐c]quinolines is described. An analogous reaction with 3‐azaisatoic anhydride furnishes 1b, or with tricyclic anhydride 3, system 4 is isolated. Spectral data is also discussed.
Synthesis of a new bridgehead nitrogen heterocyclic system. Pyrrolo [2,1‐f]‐1,2,4‐triazine derivatives
Authors: Migliara Onofrio , Petruso Salvatore , Sprio Vincenzo 
Published: April 2009

Abstract1‐Ureidopyrroles of type 6a,b prepared by the general method previously described (2), readily cyclized under basic conditions giving pyrrolo [2,1‐f]‐1,2,4‐triazine‐2,4(1H, 3H)dione derivatives.
Study of some reactions of ethyl 4‐phenyl‐3‐benzoyl‐2‐pyrazoline‐5‐carboxylate
Authors: El‐Kholy Ibrahim El‐Sayed , Mishrikey Morcos Michael , Euid‐Alla Hassan Moslafa , Nashed Mina Anis 
Published: April 2009

AbstractSeveral reactions of the pyrazoline 1a were investigated. With bromine water, potassium permanganate, hydrogen peroxide, or potassium hydroxide, different pyrazole derivatives were formed. While the reaction with hydroxylamine or some hydrazines gave the corresponding pyrazoline Schiff bases, with aroylhydrazines, pyrazole Schiff bases were formed.
The crystal and molecular structures of 1‐(P‐bromophenyl)‐5‐bromopyridazine‐3,6‐dione and 1‐(p‐bromophenyl)‐4‐diethylaminopyridazine‐3,6‐dione
Authors: Stam C. , Zwinselman J. J. , Van Der Ptas H. C. , Baloniak S. 
Published: April 2009

AbstractThe structure of 1‐(p‐bromophenyI)‐5‐bromopyridazine‐3,6‐dione was unequivocally established by means of an X‐ray crystal structure determination. By the same means its reaction product with diethylamine was proved to be 1‐(p‐bromophenyl)‐4‐diethylaminopyridazine‐3,6‐dione.
Hydroxymethylation and cyanoethylation of nitroimidazoles
Authors: Sehgal Raj K. , Agrawal Krishna C. 
Published: April 2009

AbstractA series of nitroimidazoles were subjected to hydroxymethylations under a variety of conditions. Hydroxymethylation of 1‐(2‐hydroxyethyl), 1‐(2‐acetoxyethyl), and 1‐(2‐chloroethyl) substituted 5‐nitroimidazoles with paraformaldehyde in dimethyl sulfoxide yielded the respective 2‐hydroxymethyl analogs (5–7). However, attempts to hydroxymethylate 1‐(2‐hydroxyethyl), 1‐(2‐acetoxyethyl), 1‐(2‐cyanoethyl) substituted 4‐nitroimidazoles and 1‐(2‐hydroxyethyl)‐2‐nitroimidazole were unsuccessful. Treatment of 1‐(2‐acetoxyethyl)‐5‐nitro‐2‐imidazolecar‐baldehyde(10) with hydroxylamine‐O‐sulfonic acid afforded a mixture of corresponding 2‐carbonitrile (12) and 2‐(N‐hydroxy)carboximidamide (13). Hydrolysis of 10 with ethanolic hydrochloric acid yielded 8‐ethoxy‐5,6‐dihydro‐3‐nitro‐8H‐imidazo[2,1‐c] [1,4]oxazine (11) which, on subsequent reaction with hydroxylamine‐O‐sulfonic acid, afforded 1‐(2‐hydroxyethyl)‐5‐nitroimidazole‐2‐(N‐hydroxy)carboximidamide (15). Reaction of 4(5)‐nitroimidazole with chloropropionitrile produced a mixture of the isomeric 1‐(2‐cyanoethyl) substituted 4‐ and 5‐nitroimidazoles. Treatment of 2,4(5)‐dinitroímidazole with chloropropionitrile afforded a mixture of 4(5)‐chloro‐5(4)‐nitroimidazole and 1‐(2‐cyanoethyl)‐4‐nitro‐5‐chloroimidazoIe. Reaction of nitroimidazoles with acrylonitrile in the presence of Triton B yielded the corresponding 1‐(2‐cyanoethyl) substituted derivatives.
Synthesis of 2,3‐dihydro‐5H‐oxazolo[2,3‐B]quinazolin‐5‐ones
Authors: Peet Norton P. , Anzeveno Peter B. 
Published: April 2009

AbstractIodide‐catalyzed ring expansion of 2‐[(1‐aziridinylcarbonyl)amino]benzoic acid methyl ester (2) gave 2,3‐dihydro‐5H‐oxazolo[2,3‐b]quinazolin‐5‐one (3) in quantitative yield. Treatment of the dimethyl analog of 2 (9) with sodium iodide in acetone gave a mixture of the 2,3‐dihydro‐2,2‐dimethyl‐ (10) and 2,3‐dihydro‐3,3‐dimethyl‐5H‐oxazolo[2,3‐b]quinazolin‐5‐ones (11). However, rearrangement of 9 with sulfuric acid produced only 10. Synthesis of 11 by another route for comparison is described, and the known syntheses of 2,3‐dihydro‐5H‐oxazolo[2,3‐b]quinazolin‐5‐ones are reviewed.
Synthesis and antimalarial effects of N,N‐dialkyl‐6‐(substituted phenyl)‐1,2,4,5‐tetrazin‐3‐amines
Authors: Werbel Leslie M. , Mcnamara Dennis J. , Colbry Norman L. , Johnson Judith L. , Degnan Margaret J. , Whitney Barbara 
Published: April 2009

AbstractThe synthesis of a series of N,N‐dialkyl‐6‐(substituted phenyl)‐1,2,4,5‐tetrazin‐3‐amines (IV) by two routes is described. The first route (Scheme I) involved the oxidative cyclization of formazans (II) to 3‐bromo‐6‐(substituted phenyl)‐1,2,4,5‐tetrazines (III), followed by treatment with amines. The second (Scheme II) utilized the treatment of 3‐(methylthio)‐6‐(substituted phenyl)‐1,2,4,5‐tetrazines (VII) with amines to provide the desired products. The intermediate 3‐(methylthio)‐6‐(substituted phenyl)‐1,2,4,5‐tetrazines (VII) were obtained by thiobenzoylation of hydrazinecarbohydrazonothioic acid methyl ester with [[(substituted phenyl)thioxomethyl]thio]‐acetic acids (V) to afford the 1,2‐dihydro‐3‐(methylthio)‐6‐(substituted phenyl)‐1,2,4,5‐tetrazines (VI). Oxidation with bromine in acetic acid provided the desired intermediates. The target 6‐(substituted phenyl)‐1,2,4,5‐tetrazin‐3‐amines (IV) displayed modest antimalarial activity.
Reaction of sulfene and dichloroketene with N,N‐disubstituted 5‐aminomethylene‐1,5,6,7‐tetrahydro‐2‐methyl‐1‐phenylindol‐4‐ones. Synthesis of 1,2‐oxathiino[6,5‐E] indole and of pyrano[2,3‐e] indole derivatives
Authors: Mosti Luisa , Schenone Pietro , Menozzi Giulia 
Published: April 2009

AbstractThe 1,4‐cycloaddition of sulfene to N,N‐disubstituted 5‐aminomethylene‐1,5,6,7‐tetrahydro‐2‐methyl‐1‐phenylindol‐4‐ones afforded N,N‐disubstituted 3,4,5,6‐tetrahydro‐8‐methyl‐7‐phenyl‐7H‐1,2‐oxathiino[6,5‐e]indol‐4‐amine 2,2‐dioxides only in the case of aliphatic N‐substitution. The 1,4‐cycloaddition of dichloroketene occurred normally only in the case of 1,5,6,7‐tetrahydro‐2‐methyl‐1‐phenyl‐5‐piperidinomethyleneindol‐4‐one to give 3,3‐dichloro‐3,4,5,6‐tetrahydro‐8‐methyl‐7‐phenyl‐4‐piperidino‐7H‐pyrano[2,3‐e]indol‐4‐one. Attempted recrystallisation, dehydro‐chlorination or treatment with palladium on carbon of this adduct, as well as reaction of similar enaminoketones with dichloroketene, gave instead the same product, namely 3‐chloro‐8‐methyl‐7‐phenyl‐7H‐pyrano[2,3‐e]indol‐4‐one, as a result of dehydrochlorination, dehydrogenation and subsequent hydrogenolysis of the C‐NR2 bond in the primary adduct.
Carbon‐13 nmr chemical shift‐substituent effect correlations in P‐substituted 5‐benzylidenebarbituric acids and 2‐benzylidene‐1,3‐indanediones
Authors: Robinson Charles N. , Irving Charles C. 
Published: April 2009

AbstractExcellent correlations have been observed between σ+ constants and the 13C nmr chemical shifts of several of the carbon atoms of 5‐arylidenebarbituric acids and of 2‐arylidene‐1,3‐indanediones.
υ‐Triazolines. Part XIII. Reactions of α‐ketoenamines with toluene‐P‐sulphonylazide
Authors: Pocar Donato , Rossi Luisa Maria , Trimarco Pasqualina 
Published: April 2009

AbstractSome enamines derived from α‐diketones have been reacted with tosylazide yielding unstable 5‐amino‐υ‐triazolines, which were found to undergo cyeloreversion to diazo compounds and arnidines. In the case of the enamines derived from 4‐aryl‐2,3‐butanediones, a competitive rearrangement to (Z)‐4‐aryl‐4‐arnino‐3‐tosylamino‐3‐butene‐2‐ones was observed.
Tautoméric entre structures α‐aleoxy énaminocétone et β‐céto iminoéther présentée par les pipéridéines résultant de la semihydrogénation d'alcoxy‐2 acyl‐3 pyridines
Authors: Sliwa Henri , Delaunay Luc 
Published: April 2009

AbstractL'hydrogénation partielle, en présence de palladium ou de platine, d'alcoxy‐2 acyl‐3 pyridines a été réalisée en vue d'étudier la tautoméric des tétrahydropyridines résultantes. La réduction en pipéridéine se produit sélectivement pour les composés bicycliques 2 et 3, tandis que la réduction du groupe carbonyle devient prépondérante dans le cas du dérivé 1 présentant le groupe acyle dans une chaǐne ouverte. Cetle différence de comportement est interprétée à I'aide du concept de contrainte interne (“I‐strain” effect). Alors que les tétrahydropyridines bicycliques 6 et 7 possèdent exclusivement une structure d'α‐alcoxy ènaminocétone, la pipéridéine 5 qui est substituée par des chaǐnes ouvertes existe uniquement sous forme de β‐céto iminoéther, comme le montrenl les études spectrographiques ir et de rmn. L'analyse des interactions susceptibles de se produire entre les doublets libres des hétéroalomes permet de rendre compte du déplacement total des équilibres de tautoméric vers I'une ou I'autre de ces deux structures: dans le cas des dérivés bicycliques, I'interaction destabilisante que présenterait I'iminoéther, fait place au sein de la structure ènaminocétone, à une interaction stabilisante entre le doublet de I'oxygène et la liaison N‐II, sans qu'il y ait accroissement des contraintes stériques.
Charge transfer complexes between iodine and the thioamido entity contained in some pentaatomic rings
Authors: Devillanova Francesco A. , Verani Gaetano 
Published: April 2009

AbstractSpectrophotometric investigations on the adducts of iodine with pyrrolidine‐2‐thione, 1,3‐oxazolidine‐2‐thione, 1,3‐thiazolidine‐2‐thione and N‐methyl‐1,3‐thiazolidine‐2‐thione have been carried out in carbon tetrachloride and dichloromethane solutions. These complexes show a very intense peak, due to the charge transfer band, and the well known “blue shift” of the visible band of iodine, whereas the analogous shift of the ligand is masked from the solvents. Their thermodynamic and spectral characteristics have been determined and compared with those of the series of 1,3‐imidazolidine‐2‐thione.
Synthesis of new heterocyclic ring systems. Reaction of indolines and hexahydrocarbazole with α,β‐unsaturated acids
Authors: Shankarnarayan V. , Merchant J. R. 
Published: April 2009

AbstractReactions of indoline (I), 2‐methylindoline (II) and hexahydrocarbazole (III) with α,β‐unsaturated acids in the presence of polyphosphoric acid have been investigated. Reaction of 1 with acrylic acid afforded two compounds which were identified as 1,2,4,5‐tetrahydro‐6H‐pyrrolo‐[3,2,1‐ij] quinolin‐6‐one (IV) and 2,3,5,6,9,10‐hcxahydro‐1H‐cyclopenta[f lpyrrolo [3,2,1‐ij|‐quinoline‐1,8‐dione (VII). The reaction oi 1 with crotonic acid gave compounds V and VIII, analogous‐to IV and VII. The reaction of II with acrylic acid yielded two compounds VI and IX, whereas with crotonic acid, only X was isolated. With 111, acrylic acid afforded 5,6,8,9,10. 11,8a,11a‐octahydro‐4H‐pyrido[3,2,1‐jk]carbazol‐4‐one (XI) and a compound with a heretofore unknown ring system, viz., 2,3,5,6,7,8,11,12,5a,8a‐decahydro‐1H‐cyclopenta[h] pyrido [3,2,1‐jk |earbazole‐1,10‐dione. The structures of these compounds were deduced on the basis of their spectral and analytical data.
1H nmr structural analysis of azabicyclospirohydantoins
Authors: Trigo G. G. , Gálvez E. , Espada M. , Bernal C. 
Published: April 2009

AbstractThe structure and spatial conformation of 3‐alkyl‐3‐azabicyclo[3.2.1]octane‐8‐spiro‐5′‐hydantoins and 8‐alkyl‐8‐azabicyclo[4.3.1]decane‐10‐spiro‐5‐hydantoins has been determined on the basis of the data from 1H nmr. The chair conformation of the piperidine ring and the presence of only one stereoisomer at the spiro carbon atom are corroborated. All these facts have been confirmed by x‐ray diffraction methods (2).