bluuebunny/crossref_metadata_2025 huggingface dataset:
Reaction of indol‐3(2H)‐one derivatives with some active methylene compounds
Authors: Daisley Roy W. , Elagbar Zaha A. , Walker John
Published: March 2009

The reaction of substituted (Z)‐ and (E)‐2‐arylmethylideneindolin‐3(2H)‐ones with malononitrile gave the Micheal addition products which could be cyclised to the corresponding pyrano[3,2‐b]indole. Larger molecules such as cyanoacetic acid and ethyl cyanoacetate failed to react.
The synthesis of macrocyclic polyether‐diesters incorporating 1,10‐phenanthrolino and 1,8‐naphthyridino subunits
Authors: Chandler Christopher J. , Deady Leslie W. , Reiss James A. , Tzimos Vasilios
Published: March 2009

The preparation of a series of macrocycles, formed by reaction of HO‐(‐CH2‐CH2‐O‐)nH with 1,10‐phenanthroline‐2,9‐dicarbonyl chloride (n = 2,3,4) and 1,8‐naphthyridine‐2,7‐dicarbonyl chloride (n = 3,4), is described. An improved synthetic route to 2,7‐dimethyl‐1,8‐naphthyridine 9 is also reported.
Synthesis and biological activity of some new aminoacylcarbazole derivatives. Part I
Authors: El‐Nagger A. M. , Ahmed F. S. M. , El‐Salam A. M. Abd , El‐Gazzar M. A.
Published: March 2009

The syntheses of different 9‐(N‐phthalyl‐ orN‐tosyl‐ or free aminoacyl)carbazoles and the corresponding derivatives of 3,6‐dinitrocarbazoles and some derivatives of 3,6‐diamino‐9‐(N‐phthalylaminoacyl)carbazoles (II‐XXXII) are described. Compounds VIII, XIII‐XVII and XXIII‐XXVII were found to be active against a number of microorganisms.
New heterocyclic ring systems. XIII. 7,11‐Dithiaazasteroid analogues
Authors: Cecchetti V. , Fravolini A. , Schiaffella F.
Published: March 2009

Synthesis of the tittle compounds has been achieved starting with the new tricyclic ring, 6‐methyl‐4‐oxo‐3,4‐dihydro‐2H,6H‐thiopyrano[3,2‐c][2,1]benzothiazine 5,5‐dioxide (III). This compound was converted to the glyoxylate VI, the β‐ketoester IX, a difluoride complex XIII and an enamino ketone XXIV which, by hydrazine, hydroxylamine and glycine treatment, gave 7,11‐dithiaazasteroid analogues. Some unexpected products were also obtained from the ketone XVIII and the β‐diketone XIX by treatment with chloroacetone and hydrazine respectively.
Studies on v‐triazoles. Part V. Acylation, alkylation and sulphonation reactions of ethyl 5‐(4‐hydroxyphenoxy)‐1H‐v‐triazole‐4‐carboxylate
Authors: Buckle Derek R. , Rockell Caroline J. M. , Oliver Robert S.
Published: March 2009

The alkylation of 5‐(4‐hydroxyphenoxy)‐1H‐v‐triazolecarboxylate (1) under alkaline conditions was shown to yield exclusively isomeric N‐2 and N‐3 alkylation products, the structures of which were assigned by ir, 1H nmr and, 3C nmr spectroscopy. Acylation and sulphonation under similar conditions resulted in exclusive attack at the phenolic oxygen of 1, possibly by the migration of an initially formed N‐derivative.
Die polonovski‐reaktion an 3,4‐dihydro‐4‐methyl‐2H‐1,4‐benzoxazin‐2‐carbonsäurederivaten; ein neuer syntheseweg zu 4H‐1,4‐benzoxazinen. 10. Mitteilung über studien zur chemie der 1,4‐oxazine
Authors: Bartsch Herbert , Schwarz Otto
Published: March 2009

Die Dihydro‐1,4‐benzoxazin‐2‐carbonsäurederivate 4a, 5 und 6, deren Darstellung beschrieben wird, liefern bei der Umsetzung nach einer Variante der Polonovski‐Reaktion unterschiedliche Resultate. Aus 4a werden neben 9 der Ester 7 sowie 8 erhalten, während aus 5 lediglich 10 entsteht. Verbindung 6 liefert neben 12 das Nitril 11. Die Bildung der Dehydroprodukte zeigt eine starke Abhängigkeit von der CH‐Acidität der Ausgangsverbindungen. Während die Reduktion von 7 mit Lithiumaluminiumhydrid nur Zer‐setzungsprodukte liefert, wird mit Redal® /Morpholin 16 erhalten. Die Darstellung von 17, die aus 16 unmöglich ist, gelingt mit Redal® /Morpholin aus 4a.
Synthesis of N‐alkyl derivatives of 4‐(2′‐aminoethyl)indole
Authors: Cannon Joseph G. , Demopoulos Basil J.
Published: March 2009

N‐Substituted 4‐(2′‐aminoethyl)indoles are attainable in good yields from indole‐4‐acetic acid (2). Several methods of preparation for 2 were tried or considered. A new sequence involving Arndt‐Eistert homologation of indole‐4‐carboxylic acid has been devised, which is no more laborious than a literature homologation sequence involving indole‐4‐acetonitrile, and which provides somewhat better overall yields than the literature method.
Furopyridines. I. Synthesis of furo[2,3‐c]pyridine
Authors: Shiotani Shunsaku , Morita Hiroyuki
Published: March 2009

The parent framework of furo[2,3‐c]pyridine has been synthesized. 3‐Furoic acid chloride (2) was reduced with bis(triphenylphosphine) copper(1) tetrahydroborate to afford 3‐furaldehyde (3) which was condensed with malonic acid to give β‐(3‐furyl)acrylic acid (4). The acrylic acid 4 was converted to the acid azide (5), which in turn was cyclized to give furo[2,3‐c]pyridin‐7(6H)‐one (6) by heating at 180° in diphenylmethane. The pyridone 6 was chlorinated with phosphorus oxychloride, followed by reduction with zinc and acetic acid to give furo[2,3‐c]pyridine (8).
Novel synthesis of (1‐acetylindol‐3‐yl)methyl acetate and its displacement substitution reactions
Authors: Bennett Richard , Shah Tushar , Maggiolo Allison
Published: March 2009

The acylation of gramine produces (1‐acetyindol‐3‐yl) methylacetate from which the 3‐alkoxy or thioacid derivatives have been synthesized.
Stereochemistry of thialdine
Authors: Day Cynthia S. , Hansen Thomsen J. , Keefer Larry K.
Published: March 2009

Thialdine (dihydro‐2,4,6‐trimethyl‐4H‐1,3,5‐dithiazine), 1, was shown on the basis of X‐ray diffraction data to have the all‐cis configuration, I.
A new synthesis of pyrimido[5,4‐e]‐as‐triazine 4‐oxides and their ring transformation to pyrrolo[3,2‐d]pyrimidines
Authors: Nishigaki Sadao , Kanazawa Hashime , Kanamori Yukako , Ichiba Misuzu , Senga Keitaro
Published: March 2009

A new synthesis of certain pyrimido[5,4‐e]‐as‐triazine 4‐oxides and their ring transformation to pyrrolo‐[3,2‐d]pyrimidines by the 1,3‐dipolar cycloaddition reaction is described. Thus, reaction of 6‐hydrazino‐1,3‐dimethyluracil (1) with triethyl orthoformate gave 6‐ethoxymethylenehydrazino‐1,3‐dimethyluracil (2). Treatment of 2 with arylamines gave 6‐arylaminomethylenehydrazino‐1,3‐dimethyluracils (3a‐e). Nitrosative cyclization of 3a‐e with sodium nitrite afforded 3‐arylaminofervenulin 4‐oxides (6a‐e). Reaction of 6a‐e with acetylenic esters yielded 7‐alkoxycarbonyl‐6‐arylamino‐1,3‐dimethylpyrrolo[3,2‐d]pyrimidine‐2,4(1H,3H‐diones (15a‐e and 16).
Reaction of 2‐dimethylaminomethylene‐1,3‐diones with dinucleophiles. I. Synthesis of 1,5‐disubstituted 4‐acylpyrazoles
Authors: Schenone Pietro , Mosti Luisa , Menozzi Giulia
Published: March 2009

Reaction of open‐chain and cyclic sym‐1,3‐diones with N,N‐dimethylformamide dimethyl acetal gave, generally in high yield, a series of sym‐2‐dimethylaminomethylene‐1,3‐diones which reacted with phenylhydrazine and methylhydrazine to afford, generally in satisfactory yield, a number of 1,5‐disubstituted 4‐acylpyrazoles. The applications and limits of this new pyrazole synthesis are presented and discussed.
A Novel synthesis of 5,6‐dihydro‐2,3‐bisaryl‐8H‐imidazo[2,1‐c][1,4]thiazine
Authors: Lantos I. , Razgaitis C. , Sutton B. M.
Published: March 2009

Bisaryl‐8H‐imidazo[2,1‐c][1,4]thiazines were prepared from the corresponding 2‐thiomethylimidazoles. A novel and efficient synthesis is presented for these intermediates based on the condensation of benzils with protected 2‐thioacetaldehydes.
Reactions of 3‐substituted pyrazolin‐5‐ones with isocyanates
Authors: Mitsuhashi Keiryo , Takayanagi Hisashi , Matsuno Sin‐ichi , Tanaka Kiyoshi
Published: March 2009

The reaction sites of 3‐substituted pyrazolin‐5‐ones and their O‐ and N‐blocked analogues toward various isocyanates were investigated. 3‐Methyl and 3‐ethoxycarbonylpyrazolin‐5‐ones gave the corresponding 1‐carbamoylpyrazolinones, whereas the O‐alkylpyrazoles afforded 2‐carbamoylpyrazoles. On the other hand, the N‐alkylpyrazolinones were carbamoylated at 4‐position under drastic conditions.
Transposition of the halogen atom from nitrogen to methyl groups in hydantoins
Authors: Suárez A. R. , Orio O. A. , Argüello B. V. , Balzaretti V. T.
Published: March 2009

1‐Bromo (1a) and 1‐chloro‐3,5,5‐trimethylhydantoin (1b) which are both useful halogenating and oxidizing agents, underwent halogen transposition from nitrogen to the 3‐N‐alkyl group when their boiling carbon tetrachloride solutions were irradiated.
Regioselective synthesis of 3‐hydroxyisoxazoles and 5‐isoxazolones from β‐amino α,β‐unsaturated esters
Authors: Kashima Choji , Konno Yumiko , Yoshiwara Nobutoshi , Tajima Tadakuni
Published: March 2009

The regioselective synthesis of 3‐hydroxyisoxazoles and 5‐isoxazolones is accomplished by the reaction of β‐amino α,β‐unsaturated esters with hydroxylamine hydrochloride in the presence of appropriate bases. The total yield of isoxazole derivatives is sensitively influenced on the β‐substituent group of the esters.
Conformational studies of 5‐substituted 3‐aryl‐1,2,3‐oxathiazolidine 2‐oxides using 13C‐NMR
Authors: Mizuno Takashi , Nishiyama Tomihiro , Nakai Yasushi , Yamada Fukiko
Published: March 2009

The title compounds were prepared and their 13C‐nmr spectra were examined. On the basis of the data for the magnitudes of the γ shifts and the δ effects, four isomeric conformations of the compounds were discussed.
Studies on nitrile imines. Synthesis of some new five‐membered heterocyclics via N‐(2,4‐dinitrophenyl)‐C‐alkyl nitrile imines
Authors: Tewari R. S. , Dixit P. D. , Parihar Miss P.
Published: March 2009

Reaction of N‐(2,4‐dinitrophenyl)‐C‐alkyl hydrazonyl chlorides with diverse dipolarophiles gave a variety of novel heterocyclics, which are expected to possess biological activities. The ring closure is brought about by a concerted process involving nitrile imine as an intermediate. The structures of the resulting products are supported by nmr and ir spectral data.
Reaction of schiff bases with acrylamides. Synthesis of 2‐oxotetrahydropyridines
Authors: Barluenga José , Muñiz Laudina , Palacios Francisco , Gotor Vicente
Published: March 2009

Ketimines react with acrylamide and methacrylamide in the presence of aluminium chloride to afford 2‐oxotetrahydropyridines by a C‐alkylation pathway.
Synthesis and reactions of ethyl 3‐acetyl‐8‐cyano‐6,7‐dimethylpyrrolo[1,2‐a]pyrimidine‐4‐carboxylate and related compounds
Authors: Kurihara Takushi , Nasu Keiko , Adachi Yasuko
Published: March 2009

The reactions of 3‐acetyl‐4‐ethoxycarbonyl‐ or 3,4‐diethoxycarbonylpyrrolo[1,2‐a]pyrimidine derivatives7a,b, which were prepared by condensation of the 2‐aminopyrrole (4) with ethyl 3‐ethoxymethylene‐2,4‐dioxovalerate (5a) or ethyl ethoxymethyleneoxaloacetate (5b), with diazomethane are described. Thus, reaction of7a, with diazomethane gave ethyl 2a‐acetyl‐7‐cyano‐2a,3a‐dihydro‐5,6‐dimethyl‐3H‐cyclopropa[e]pyrrolo[1,2‐a]pyrimidine‐3a‐carboxylate (11) in 74% yield, which was readily transformed into the 1‐pyrrol‐2‐yl‐pyrrole (18) by treatment with potassium hydroxide. On the other hand, reaction of7bwith diazomethane afforded three products whose structures were assigned as diethyl 7‐cyano‐2a,3a‐dihydro‐5,6‐dimethyl‐3H‐cyclopropa[e]pyrrolo[1,2‐a]pyrimidine‐2a,3a‐carboxylate (20), 6‐cyano‐7,8‐dimethyl‐3a,3b,5,9a‐tetrahydro‐4H‐aziridino[c]‐1Hor 3H‐pyrazolo[3,4‐e]pyrrolo[1,2‐a]pyrimidine‐3a,9a‐dicarboxylates (21,22). Ring Transformation of20 to 25was not observed.
Thiényl‐ et séléniénylthiocyanates et sélénocyanates. 4. Synthèses de thiéno[2,3‐d]thiazoles, de thiéno[2,3‐e]thiazines et de quelques analogues sélénophéniques
Authors: Paulmier Claude , Outurquin Francis
Published: March 2009

Différents processus sont envisagés afin d'accèder à des thiophénes et des sélénophenes orhto ‐disubstitués possèdant une fonction aminée en position α et un reste sulfuré ou sélénié en position β. La substitution nuc‐léophile de l'ion bromure des bromo‐3 nitro‐2 thiophène et sélénophène par les ions thiocyanate et séléno‐cyanate, dans le diméthylsulfoxyde, est une excellente voie d'accès à ces composés. La réduction du groupe nitré fournit des amines protégées par acylation. Des réactions de cyclisation réalisées sur certains thioethers et thiolesters conduisent à des thiéno[2,3‐d]thiazoles et sélénolo[2,3‐d]thiazoles ainsi qu'à la 4H‐dihydro‐2,3 oxo‐3 thiéno[2,3‐e]thiazines‐1,4 et à son analogue sélénophénique.
An application of the mannich reaction using hydroxylamine and some of its derivatives. 6‐Substituted‐2,4‐diamino‐5,6,7,8‐tetrahydropyrimido[4,5‐dpyrimidines
Authors: Delia Thomas J. , Kirt Diane D. , Sami Salah M.
Published: March 2009

Hydroxylamine and some of its O‐substituted derivatives (2) have been used as the amine component in Mannich reactions with 2,4,6‐triaminopyrimidine (1). The resulting 6‐substituted tetrahydropyrimido[4,5‐d]‐pyrimidines (3) contain an N‐0 bond linking the substituent to the ring. These results extend the utility of this modified Mannich reaction to otherwise inaccessible substituents. Reaction conditions, spectral data and certain limitations of the reaction are discussed.
Assignments of dissociation constants of primaquine by13C‐NMR spectroscopy
Authors: Hufford Charles D. , Mcchesney James D. , Baker John K.
Published: March 2009

The first and second dissociation constants of primaquine have been determined by titration in acetonitrile‐water mixtures and estimated in pure water by using linear regression analysis. The assignments of dissociation constants were unambiguously achieved by studying the13C nmr spectral data obtained on the mono‐, di‐, and trihydrochloride salts.
Etude de la réaction de l'acétylacétone avec les diamines hétéroaromatiques
Authors: Essassi E. M. , Zniber R. , Bernardini A. , Viallefont PH.
Published: March 2009

L'action d'une β‐diacétone telle l'acétylacétone sur un certain nombre d'o‐diamines hétéroaromatiques met en évidence l'influence de la nature de l'o‐diamine de départ sur les produits de la réaction. Lorsque l'o‐diamine de départ est une diamino‐2, 3 ou ‐3, 4 pyridine un seul intermédiaire crotonique cyclisable en imidazo[4, 5‐b]pyridine est obtenu alors qu'à partir de diamino‐1, 5 imidazoles deux réactions concurrentes conduisent aux imidazo[4, 5‐b]pyridines et aux imidazo[1, 5‐b]triazépines; dans le cas des diamino‐3, 4 triazoles, des produits de structure triazolopyridazine peuvent‐ětre synthétisés.
Application of polymer‐bound thiazolium salts to the synthesis of acyloins and benzoins: Effects of solvent and substituents of the thiazolium nucleus
Authors: Karimian Khashayar , Mohanazadeh Farajolah , Rezai Shaheen
Published: March 2009

Covalent immobilization of the thiazole nucleus on a chloromethylated polystyrene copolymer results in the formation of a catalytically active thiazolium salt, capable of repeated acyloin and benzoin condensations. The nature of the solvent and the substituents on the thiazolium nucleus has been found to have marked effects of the rate of catalysis.
N‐polylazolylméthanes. III.. Synthèse et étude rmn du proton des dérivés du méthylène‐1,1′ diimidazole et du méthylène‐1,1′ dibenzimidazole
Authors: Claramunt Rosa Maria , Elguero José , Meco Teresa
Published: March 2009

Un certain nombre de sels quaternaires du méthylene‐1,1′ diimidazole et du méthylène‐1,1′ dibenzimidazole ont été préparés et étudiés par résonance magnétique du proton comparativement aux sels quaternaires de méthyl‐1 imidazole et méthyl‐1 benzimidazole. L'effet des chélates d'europium ainsi que des expériences d'effet overhauser nucléaire ont été utilisées pour l'attribution des protons.
Hydrazination of pyridazines and phthalazines
Authors: Counotte‐Potman A. , Van Der Plas H. C.
Published: March 2009

It is shown by15N‐labelling techniques that hydrazination of pyridazines partly occurs according to a reaction pathway, involving addition of the nucleophile (hydrazine), ring opening and ring closure (SN(ANRORC)‐mechanism). It is also proved that phthalazines undergo hydrazination without ring opening (SN(AE)‐mechanism).
Chemical and X‐Ray crystallographic characterization of the reaction products in the 1,3‐dipolar cycloaddition of diazomethane to p‐toluquinone
Authors: Conway Gregory A. , Loeffler Larry J.
Published: March 2009

The product 2 in the 1,3‐dipolar cycloaddition of one equivalent of diazomethane to p‐toluquinone (1) was determined by 250 MHz nmr spectra to be approximately 85% 6‐methyl‐1‐H‐indazole‐4,7‐dione (2b). X‐ray crystallographic analysis was employed in the characterization of 1,6‐dimethyl‐1‐H‐indazole‐4,7‐dione (4a), which was the major 1‐N‐methyl regioisomer in the methylation of the cycloaddition mixture 2 with diazomethane. Methylation of the cycloaddition product 2 with diazomethane also provided a regioisomeric mixture of the 2‐N‐methyl derivatives 5. This mixture was synthesized for characterization by an independent method which utilized the cycloaddition of 3‐methylsydnone (10) to toluquinone (1). 1,5,6‐Trimethyl‐1‐H‐ind‐azole‐4,7‐dione (9) was found to be a minor product in the reaction of diazomethane with the cycloaddition product 2.
3,3′‐Oxybispyridine and the polarographic reduction of 1,1′‐dimethyl‐3,3′‐oxybispyridinediium diiodide
Authors: Barker David J. , Summers Lindsay A.
Published: March 2009

3,3′‐Oxybispyridine is prepared by reaction of 3‐hydroxypyridine with 3‐bromopyridine and converted to the 1,1′‐dimethyl diquaternary salt with methyl iodide. The salt is reduced polarographically by a one electron transfer not involving hydrogen to an unstable radical cation at a potential (Eo) of −0.81 V in the pH range 6.3‐12.0.
The use of 2‐0xazolidinone as a latent aziridine equivalent. I. A facile method for the preparation of 2‐substituted oxazolines
Authors: Poindexter Graham S.
Published: March 2009

Ring‐opening reaction of 2‐oxazolidinone with acid chlorides followed by treatment with aqueous sodium hydroxide yields 2‐substituted oxazolines.
Synthesis of some benzimidazole‐ and benzothiazole‐derived ligand systems and their precursory diacids
Authors: Addison Anthony W. , Rao T. Nageswara , Wahlgren Curtis G.
Published: March 2009

Procedures are described for the preparation of various bidentate and linear tetradentate benzimidazoles and benzothiazoles incorporating units such as pyridyl and thioether, and for the preparation of certain thioether dicarboxylic acids precursory to them. Condensations of ortho‐functinal anilines with carboxylic acids were carried out in polyphosphoric acid or refluxing HCl solution. Syntheses are reported for: [HO2C(CH2)2S(CH2)2]2X (X = O, S), 1,9‐bis(benzimidazol‐2‐yl)‐2,5,8‐trithianonane, 1,11‐bis(N‐methylbenzimidazol‐2‐yl)‐3,6,9‐trithiaundecane, 1,11‐bis(2‐benzimidazol‐2‐yl)‐6‐oxo‐3,9‐dithiaundecane, 2‐(2‐pyridyl)benzothiazole, 2,6‐bis(benzothiazol‐2‐yl)pyridine, 2‐(2‐pyridyl)‐N‐methylbenzimidazole, 2‐(2‐pyridylmethyl)benzimidazole and 2‐(N‐methyl‐2‐piperidyl)benzimidazole. The compounds were characterized, where appropriate, by their mass, uv and 1H‐nmr spectra.
Synthesis of 3,4‐dihydrothioxanthene‐1,9‐dione analogs as potential antimalarial agents
Authors: Hung Jocelyn , Mcnamara Dennis J. , Werbel Leslie M.
Published: March 2009

7‐Chloro‐3‐(2,4‐dichlorophenyl)‐3,4‐dihydro‐1H‐thioxanthene‐1,9 (2H)‐dione (10), and a variety of analogs and derivatives were prepared as sulfur isosteric analogs of the acridinedione antimalarial agent, floxacrine. The compounds were devoid of antimalarial activity against P. berghei in mice.
Propriétés de la benzopyranno[1][2,3‐b]quinoxalinone‐12
Authors: Vinot Nicole , Bellec Christian , Maitte Pierre
Published: March 2009

La coupure, en milieu alcalin, de la benzopyranno[1][2,3‐b]quinoxalinone‐12 conduit à l′(o‐hydroxybenzoyl)‐3 1H‐quinoxalinone‐2. Cette cétone réagit avec l′hydroxylamine et avec la phénylhydrazine pour donner, selon les conditions de la réaction, soit les dérivés caractéristiques attendus, soit ceux de la benzopyrannoquinoxalinone. La réduction de la benzopyranno[1][2,3‐b]quinoxalinone‐12 n'est pas réalisable par les méthodes chimiques. Par contre, par voie électrochimique, il est possible d'accéder à un composé dihydrogéné sur le noyau pyrazinique.
Benzo[b]thiophene derivatives. XXVII. 5‐methoxy‐6‐halo‐3‐β‐acetamidoethylbenzo[b]thiophenes, blocked analogs of melatonin
Authors: Campaigne E. , Kim Chung S.
Published: March 2009

The preparation of the 6‐fluoro and 6‐chloro analogs of the title compound is described, in a seven‐step synthesis giving 30‐40% overall yields. All intermediates have been isolated and characterized, including important by‐products, such as the corresponding benzo[b]thienyl‐3‐acetic acids, and 3‐methylbenzo[b]thiophenes. Cyclization of the 3‐halo‐4‐methoxyphenylthioacetoacetic esters gave moreortho‐cyclization in the chlorine case than was observed for the fluorine derivative. The title compounds were shown to have weak antiovulatory action, with the fluoro analog most active.
Reaction of tropone hydrazones with heterocumulenes such as isocyanate, ketene, and sulfene
Authors: Kajigaeshi Shoji , Matsuoka Shingo , Kanemasa Shuji , Noguchi Michihiko
Published: March 2009

Tropone benzoyl‐ and tosylhydrazones underwent the [8+2] cycloaddition reaction with isocyanates to afford the cyclohepta[d]imidazolin‐2‐one derivatives. This means that these hydrazones behaved as 8‐amino‐8‐azaheptafulvenes. Also, the tropone hydrazones reacted with phenylketene and phenylsulfene in more complicated manners.
Nitration of 5,6,7,8‐tetrahydro‐5,8‐methanoisoquinoline N‐oxide with other aromatic substitutions. Isolation and mutagenicity of an α‐nitropyridine N‐oxide
Authors: Tanida Hiroshi , Irie Tadashi , Wakisaka Yoshiharu
Published: March 2009

Treatment of 5,6,7,8‐tetrahydro‐5,8‐methanoisoquinoline N‐oxide (2) with fuming nitric acid afforded 3‐nitro‐5,6,7,8‐tetrahydro‐5,8‐methanoisoquinoline N‐oxide (3), an example of formation of an α‐nitropyridine N‐oxide derivative by nitration of N‐oxides. Further reaction of 3 resulted in deoxygenation giving 3‐nitro‐5,6,7,8‐tetrahydro‐5,8‐methanoisoquinoline (4). No aromatic nitration was observed by similar treatment of 5,6,7,8‐tetrahydro‐5,8‐methanoisoquinoline (1) or 5,6,7,8‐tetrahydroisoquinoline N‐oxide (11). Some other aromatic substitutions with 1 and 2 were caried out to obtain mainly the 3‐substituted derivatives. Significant mutagenicity of 3 is briefly reported.
Studies on pyrrolidinones. A convenient synthesis of 5‐cyano‐2‐pyrrolidinone derivatives
Authors: Rigo Benoǐt , Lespagnol Charles , Pauly Marc
Published: March 2009

The reaction of 2‐pyrrolidinone‐5‐carboxamide (pyroglutamide) with trimethylchlorosilane and zinc chloride as a catalyst afford in one step a 91% yield of N‐trimethylsilylpyroglutamic acid nitrile whose acylation gives N‐acyl compounds 2b,c.
Synthesis of aldehyde and carboxylic acid derivatives from 2‐hydroxymethyl‐3‐hydroxy‐4H‐pyran‐4‐one (α‐hydroxymaltol)
Authors: Looker James H. , Cliffton Michael D.
Published: March 2009

α‐Hydroxymaltol (2‐hydroxymethyl‐3‐hydroxy‐4H‐pyran‐4‐one) (1) has been converted to the 3‐O‐methyl ether 2 and 3‐O‐p‐nitrobenzyl ether 4 by standard methods. The ethers 2 and 4 have been oxidized by barium manganate to the corresponding aldehydes, 3 and 5, in 91 and 77% yields respectively. Long‐term reaction of 5 with hydrogen bromide in acetic acid gives 3‐hydroxy‐4H‐pyran‐4‐one‐2‐carboxaldehyde (6). The aldehyde 3 is readily oxidized by short‐term reaction with silver oxide to the corresponding acid 7.
Ring contraction of a 5‐acetylpyrimidine into pyrazoles by the action of substituted hydrazines in acidic medium
Authors: Menichi Gabriel , Boutar Mohamed , Kokel Bruno , Takagi Kaname , Hubert‐Habart Michel
Published: March 2009

We have found previously that two 5‐acetyl‐4‐methylpyrimidines could be transformed by aminoguanidine hydrochloride into 4‐acetyl‐1‐amidino‐3‐methylpyrazolyl amidinohydrazone dihydrochloride. This reaction beside the fact that it led to a molecule closely related to the antitumor drug M.G.B.G. pointed out to a new possibility of ring contraction of pyrimidines into pyrazoles. We attempted therefore to study the possibility of extending this transformation to other substituted hydrazines and to define more accurately the conditions of this reaction as well as to prepare new potential anticancer drugs.
A facile synthesis of novel 1‐aryl‐1H‐pyrazolo[3,4‐b]quinoxalines
Authors: Kurasawa Yoshihisa , Yamazaki Kaoru , Tajima Setsuko , Okamoto Yoshihisa , Takada Atsushi
Published: March 2009

The reactions of 3‐methyl‐2‐oxo‐1,2‐dihydroquinoxaline 3 with chlorophenyl diazonium salts afforded the hydrazones 4a‐c, whose chlorinations with phosphoryl chloride gave the dichlorides 5a‐c. Refluxing of the dichlorides 5a‐c and base in N,N‐dimethylformamide provided the 1‐aryl‐1H‐pyrazolo[3,4‐b]quinoxalines 6a‐c.
Syntheses of β‐hydroxyselenides and selenides from 1,2,3‐selenadiazoles: Selenophilic reaction of phenylmagnesium bromide on α‐selenoketones
Authors: Ganjian I. , Dimeo S. V. , Gomez L. A. , Lalezari I.
Published: March 2009

α‐Selenoketones were prepared starting from 1,2,3‐selenadiazoles and α‐haloketones and were reduced to corresponding β‐hydroxyselenides. The action of phenylmagnesium bromide on α‐selenoketones was studied. Selenium was the site of nucleophilic attack by Grignard reagent.
Ring transformation of 4‐amino and 4‐N‐(substituted)amino‐1H‐1,5‐benzodiazepine‐3‐carbonitriles with hydroxylamine. A new synthesis of benzimidazolidine and isoxazole derivatives
Authors: Okamoto Yoshihisa , Takagi Kaname
Published: March 2009

The reaction of 4‐amino‐1H‐1,5‐benzodiazepine‐3‐carbonitrile 1 with hydroxylamine provided the ring‐opened hydroxylamine adduct 2 which was converted to 2‐benzimidazolidinylidene‐3‐hydroxyiminopropio‐nitrile 4 in hydrochloric acid. The reaction of 4‐ethoxycarbonylamino‐1H‐1,5‐benzodiazepine‐3‐carbonitrile 6a or N‐(3‐cyano‐1H,5‐benzodiazepin‐4‐yl)‐N′‐ethylurea 6b with hydroxylamine afforded 5‐(o‐aminoanilino)‐4‐cyanoisoxazole 3 which underwent a facile rearrangement into 4 with a base.
1‐Arylsulfonylamino‐1,2,3‐triazole derivatives from functionalyzed 1,2‐cyclohexanediones
Authors: Benedetti F. , Bozzini S. , Forchiassin M. , Nardin G. , Pitacco G. , Russo C. , Valentin E.
Published: March 2009

The heterocyclization reaction of arylsulfonylhydrazones from alkyl substituted 1,2‐cyclohexanediones is sensitive to the steric requirements of the alkyl groups. A mechanism for the cyclization in acidic medium is also reported.
NMR study of 1‐azatricyclo[3.3.1.13‐7]decane derivatives
Authors: Fernandez M. J. , Galvez E. , Lorente A. , Iriepa I. , Soler J. A.
Published: March 2009

1‐Azatricyclo[3.3.1.13‐7]decan‐4‐one (4‐oxo‐1‐azaadamantane) and 1‐azatricyclo[3.3.1.13‐7]decane‐4‐α(β)‐ol (4‐α‐(β)‐hydroxy‐1‐azaadamantane) have been studied by 1H and 13C nmr methods. From this study several stereo and stereoelectronic effects have been deduced. The complete proton and carbon chemical shift assignments for the title compounds have been made, with the aid of two‐dimensional nmr techniques.
Differences in reactions of vinyl derivatives of pyrrole and thiophene with acetylenic esters
Authors: Lee Chang Kiu , Ahn Yu Mi
Published: March 2009

1‐Methyl‐2‐vinylpyrrole and 2‐vinylthiophene showed remarkable differences in reactivity and regioselectivity upon reaction with methyl propiolate, respectively forming dimethyl 1‐methylindole‐4,7‐dicarboxylate and dimethyl benzo[b]thiophene‐4,6‐dicarboxylate. 1‐Methyl‐2‐(1‐propenyl)pyrrole reacted with dimethyl ace‐tylenedicarboxylate to give Diels‐Alder and Michael‐type adducts. On the other hand, 2‐(1‐propenyl)thiophene gave a 1:2 adduct which results via an initial cycloaddition and subsequent ene reaction.
Synthesis of a novel heterocyclic system: 2‐oxo‐1,3‐dioxolo[4,5‐c]pyridine‐6‐carboxylic acid, phenylmethyl ester
Authors: Singh Janak , Kissick Thomas P. , Mueller Richard H.
Published: March 2009

The synthesis of heterobicyclic carbonate 4 and its conversions to the mixed carbonate 5 and carbamate 6 are described.
Benzimidazole condensed ring systems. 4. New approaches to the synthesis of substituted pyrimido[1,6‐a]‐benzimidazole‐1,3(2H,5H)‐diones
Authors: Badawey El‐Sayed A. M. , Rida Samia M. , Soliman Farid S. G. , Kappe Thomas
Published: March 2009

The synthesis of some substituted 1,3‐dioxopyrimido[1,6‐a]benzimidazole‐4‐carbonitriles 6a,b and 4‐ethyl carboxylates 6c,d through condensation of 1H‐benzimidazole‐2‐acetonitriles 3a,b and ethyl 1H‐benzimidazole‐2‐acetates 3c,d, respectively, with ethoxycarbonyl isocyanate 4 are reported. The esters 6c,d were also obtained by condensing 3c, or d with chlorosulfonyl isocyanate 7. The alkylation of 5 and 6 with trimethyl or triethyl phosphate 9a, or b to obtain the N,N‐dialkyl derivatives 10a‐e and 11 are also described. Representative compounds were tested against P‐388 lymphocytic leukemia in mice and for herbicidal and plant fungicidal activities but were inactive.
The reaction of α,β‐unsaturated aldimines with benzofuroxan
Authors: Devi Purabi , Sandhu Jagir S.
Published: March 2009

Benzofuroxan reacts with imines derived from crotonaldehyde and cinnamaldehyde, to form 2‐imino‐methylquinoxaline 1,4‐dioxides.
Synthesis of new fluorescent dyes in the benzoxazinone series: Aminobenzoxazinones with a rigidized structure
Authors: Le Bris Marie‐Thérèse
Published: March 2009

The structure of 7‐aminobenzoxazinones was modified by enclosing their amino nitrogen atom in a julolidyl ring. This rigidization was expected to enhance the fluorescence performances in this series. Several fluorescent dyes and styryl derivatives were prepared and their spectral characteristics were investigated. Comparison with homologous benzoxazinones with a flexible amino group shows that rigidization does not improve the quantum yield and the photochemical stability, in contrast with the results reported for other classes of dyes, like coumarins or rhodamines.
Synthesis and spectral data of pyrido[2,3‐e]‐as‐triazines
Authors: Pié N. , Quéguiner G.
Published: March 2009

The pyrido[2,3‐e]‐as‐triazine and its 3‐phenyl derivatives were prepared via cyclisation with polyphosphoric acid of suitable 3‐substituted 2‐aminopyridines obtained by reduction of the corresponding 2‐nitropyridines. The 3‐substituted 2‐nitropyridines were obtained by action of hydrazine or benzoylhydrazide with the appropriate 3‐halo‐2‐nitropyridines; only 3‐fluoro‐2‐nitropyridine leads to the 3‐substituted 2‐nitropyridines. This experimental results are in agreements with the CNDO and MNDO calculations.
Bruceines D, E and H
Authors: Li Xian , Wu Lijun , Konda Yaeko , Iguchi Mieko , Takahasi Hiroshi , Harigaya Yoshihiro , Onda Masayuki
Published: March 2009

The absolute stereochemistry of bruceines D, E and H has been confirmed to be 1S, 5S, 7R, 8R, 9R, 10S, 11R, 12S, 13R, 14R, 15R and additionally 2S for bruceine E by a combination of 2D nmr [1H‐1H and 1H‐13C (one‐bond and long‐range) COSY] nOe and cd spectroscopic analyses.
Potential antitumor agents. III. Synthesis of pyrazolo[3,4‐e]pyrrolo[3,4‐g]indolizine and 1H‐pyrazolo[3,4‐e]indolizine derivatives
Authors: Artico Marino , Massa Silvio , Stefancich Giorgio , Silvestri Romano , Di Santo Roberto , Corelli Federico
Published: March 2009

The preparation of 5‐dimethylaminoethyl‐4,6‐dioxo‐1‐phenyl‐1,4,5,6‐tetrahydropyrazolo[3,4‐e]pyrrolo‐[3,4‐g]indolizine, a derivative of the still unknown tetracyclic parent ring pyrazolo[3,4‐e]pyrrolo[3,4‐g]indolizine, is reported starting from 1‐phenyl‐5‐(1‐pyrryl)pyrazole‐4‐acetonitrile by PPA catalyzed double cyclization of the related oxalylcyanomethyl derivative and subsequent alkylation. The synthesis of 4,5‐bis(isopro‐pylaminocarbonyloxymethyl) and 4,5‐bis‐(cyclohexylaminocarbonyloxymethyl) derivatives of 1‐phenyl‐1H‐pyrazolo[3,4‐e]indolizine is also described. The new tricyclic and tetracyclic derivatives were tested as potential antitumor agents.
6‐aza‐5,8,10‐trideaza analogues of tetrahydrofolic acid and tetrahydroaminopterin: Synthesis and biological studies
Authors: Rosowsky Andre , Bader Henry , Moran Richard G. , Freisheim James H.
Published: March 2009

6‐Aza‐5,8,10‐trideaza‐5,6,7,8‐tetrahydrofolic acid (3) and 6‐aza‐5,8,10‐trideaza‐5,6,7,8‐tetrahydroamino‐pterin (4) were synthesized from 6‐aza‐5,8,10‐trideaza‐5,6,7,8‐tetrahydropteroic acid (5) and 4‐amino‐6‐aza‐5,8,10‐trideaza‐4‐deoxy‐5,6,7,8‐tetrahydropteroic acid (6), respectively, by mixed carboxylic‐carbonic anhydride condensation with dimethyl L‐glutamate followed by ester hydrolysis. The pteroic acid analogues5and6were prepared in several steps from 1‐benzyl‐3‐carbethoxypiperidin‐4‐onevia2‐amino‐6‐benzyl‐5,6,7,8‐te‐trahydropyrido[4,3‐d]pyrimidin‐4(3H)‐one (7). Compound3did not inhibit the growth of L1210 mouse leukemia cells in culture, and was not an inhibitor of dihydrofolate reductase (DHFR) or thymidylate synthase (TS). It was a very poor substrate for mouse liver folylpolyglutamate synthetase (FPGS). The 2,4‐diamino analogue4was only a marginal substrate for FPGS, yet showed activity comparable to methotrexate as a DHFR inhibitor and as an inhibitor of tumor cell growth. The cytotoxicity of4is noteworthy because this compound is, to our knowledge, the first example of a classical antifolate which forms polyglutamates poorly even though it contains an intactp‐aminobenzoyl‐L‐glutamic acid side‐chain. The inability of3and4to form polyglutamates indicates that a basic nitrogen at position 6 is highly unfavorable for binding to FPGS.
Imidazo[2,1‐b]thiazole carbamates and acylureas as potential insect control agents
Authors: Andreani Aldo , Rambaldi Mirella , Carloni Patricia , Greci Lucedio , Stipa Pierluigi
Published: March 2009

Imidazo[2,1‐b]thiazole carbamates and acylureas were prepared by reaction of 5‐hydroxymethylimidazo‐[2,1‐b]thiazole and imidazo[2,1‐b]thiazole‐5‐carboxyamide with arylisocyanates. The products formed depend from the substituent bonded at the 6 position of the imidazothiazole moiety, and from the reaction conditions.
An improved synthesis of indazole‐3‐carboxylic acid
Authors: Ferrari Marinella , Ripa Alberto , Ripa Giorgio , Sisti Massimo
Published: March 2009

A new and efficient synthesis of indazole‐3‐carboxylic acid is reported. The method consists in reacting β‐acetylphenylhydrazine with chloral hydrate and hydroxylamine hydrochloride in acidic medium to afford N‐acetylaminoisonitrosoacetanilide which, in turn, is converted into the title compound by treatment with sulphuric acid.
Sodium periodate oxidation of tetrahydro‐β‐carboline derivatives
Authors: Gatta Franco , Misiti Domenico
Published: March 2009

The oxidation of some 3‐(methoxy‐ and ethoxycarbonyl)tetrahydro‐β‐carboline derivatives with sodium periodate led to the formation of 1, 4‐benzodiazonine derivatives or fully aromatic β‐carbolines depending on both nature and number of substituents at 1‐position.
Reaction of 1‐(3, 4‐dimethoxybenzylidene)‐6, 7‐dimethoxyisochroman‐3‐one with lithium aluminium hydride: Formation of 1‐(3, 4‐dimethoxybenzylidene)‐6, 7‐dimethoxyisochroman
Authors: Domínguez E. , Iriondo C. , Laborra C. , López P. , Martínez J. , Zamora F.
Published: March 2009

Evidence is presented to indicate that the reductive reaction of the isochromanone derivative 1 by means of lithium aluminium hydride (LAH), yielded the isochroman 2 together with small amounts of naphthalene derivatives. All new compounds have been identified from spectroscopic and analytical data.
Syntheis of 2‐aryloxy‐ and 2‐arylalkoxy‐1‐(2‐piperidyl)ethanols
Authors: Mauleón David , Pujol M. Dolors , Minguillón Cristina , Miquel Jaume
Published: March 2009

The preparation and separation of diastereomeric pairs of a series of 2‐aryloxy‐ and 2‐arylalkoxy‐1‐(2‐piperidyl)ethanols is reported. The erythro aminoalcohols were converted into threo isomers by thionyl chloride treatment of their N‐acetyl derivatives and alkaline hydrolysis.
Ring‐degenerate rearrangement of 5‐amino‐4‐iminomethyl‐1, 2, 3‐triazoles
Authors: L'Abbé Gerrit , Vandendriessche Anna
Published: March 2009

5‐Amino‐4‐(substituted)iminomethyl‐1‐phenyl‐1, 2, 3‐triazoles 5 rearrange thermally to 4‐amidino‐substituted triazoles 6 instead of undergoing the Dimroth rearrangement to 5‐anilinotriazoles 3.
Diels‐alder reactions of 3, 6‐diphenyl‐1, 2, 4, 5‐tetrazine and 3, 6‐di(2‐pyridyl)‐1, 2, 4, 5‐tetrazine with some 1‐morpholinocycloalkenes
Authors: Atfah M. Adnan
Published: March 2009

The reactions of 3, 6‐diphenyl‐1, 2, 4, 5‐tetrazine 1 and 3, 6‐di(2‐pyridyl)‐1, 2, 4, 5‐tetrazine 2 with the enamines 3a‐d derived from morpholine and the 5‐,6‐,7‐ and 8‐membered cyclic ketones have been investigated. A number of pyridazine derivatives 4–7 most of which are new have been reported. Moreover, a novel procedure for the aromatization of pyridazines 5a‐d to the corresponding pyridazine 7b‐d via oxidative elimination using hydrogen peroxide is described. The structures of products 4–7 were confirmed by spectral methods and elemental analysis.
Studies on pyrazines. 18. A new and convenient synthesis of 2‐amino‐3‐cyanopyrazine
Authors: Sato Nobuhiro
Published: March 2009

The titled compound, 2‐amino‐3‐cyanopyrazine (1), was prepared by reaction of 3‐aminopyrazine 1‐oxide (7) with trimethylsilyl cyanide. Furthermore, conditions of individual steps in synthetic route to 7 starting from 2‐pyrazinecarboxamide were optimized.
Preparation, lithiation and transformation of N‐(benzotriazol‐1‐ylmethyl) heterocycles
Authors: Katritzky Alan R. , Drewniak‐Deyrup Malgorzata , Lan Xiangfu , Brunner Frederic
Published: March 2009

Indole, carbazole, pyrrole, imidazole, benzimidazole, 2‐methyl‐ and 2‐phenylbenzimidazole, and 1, 2, 4‐triazole have each been converted into their N‐(benzotriazol‐1‐ylmethyl) derivatives. The pyrrole, indole, and carbazole adducts undergo smooth lithiation at the inter‐ring methylene group and subsequent reaction there with electrophiles. For the imidazole, benzimidazole, and triazole systems, lithiations at other molecular positions competed.
Synthesis and13C‐NMR study of novel pyrazolo[5′,1′:3, 4][1, 2, 4]triazino[5, 6‐d]pyrimidines
Authors: Kurasawa Yoshihisa , Kamigaki Yumiko , Kim Ho Sik , Futatsukawa Rika , Kanoh Megumi , Okiyama Mari , Takada Atsushi , Okamoto Yoshihisa
Published: March 2009

The pyrazolo[5′, 1′:3, 4][1, 2, 4]triazino[5, 6‐d]pyrimidines5a‐c, 6were synthesized from the pyrazolo[5, 1‐c]‐[1, 2, 4]triazines1a, cand the ring carbon signals of5a‐c, 6were assigned by the aid of coupling constant [J(13C‐1H)] data.
ortho effect on the nitrosation of the 2,3‐diphenyl‐5(2‐methoxyphenyl)pyrrole
Authors: Ceraulo Leopoldo , Agozzino Pasquale , Ferrugia Mirella , Sprio Vincenzo
Published: March 2009

A comparison of the behaviour on the nitrosation of the isomers 5‐(2‐methoxyphenyl)‐ (1a) 5‐(3‐methoxyphenyl)‐ (1b) and 5‐(4‐methoxyphenyl)2,3‐diphenylpyrroles (1c) carried out in the usual way with iso‐amyl nitrite in a solution of sodium ethoxide in ethanol evidences that 1a is dramatically less reactive with respect to 1b and 1c. The different reactivity was ascribed to the occurrence of a strong hydrogen bond involving pyrrole NH and the ortho‐methoxy group.
Mass spectral study of differently substituted 2‐oxo‐ and 2‐thioxo‐1,3,4‐benzotriazepines
Authors: Vainiotalo P. , Mälkönen P. J. , Richter P. , Morgenstern O.
Published: March 2009

The mass spectra of seven 2‐thioxo‐ and four 2‐oxo‐1,3,4‐benzotriazepines were recorded under electron ionization, and the fragmentation patterns were elucidated by exact mass measurement and metastable ion analysis. Some variations in the nature and position of the substituents greatly affected the mass spectra, allowing easy differentiation of isomeric compounds. The most characteristic feature of the mass spectral behavior of the compounds was the large number of ring contraction and complicated rearrangement reactions.
2‐(o‐Hydroxyanilido)alkylnitriles vs. 2‐[1‐(o‐hydroxyanilido)alkyl]‐benzoxazoles as products from o‐aminophenol and cyanohydrins
Authors: Huang Jamin , Haigh Dianne S.
Published: March 2009

The reaction of o‐aminophenol with cyanohydrins leads to the formation of novel benzoxazoles 2 or the expected 2‐(o‐hydroxyanilido)alkylnitriles 3 or mixtures of these two, depending on the alkyl substituents on the cyanohydrin. The formation of benzoxazoles 2 was found to be due to the intrinsic instability of the corresponding 2‐(o‐hydroxyanilido)alkylnitriles, such as 4.
Chemistry of 5(2H)‐isoxazolones: Novel conversion of positional isomers
Authors: Batra Sanjay , Akhtar Mohammad Shamim , Seth Manju , Bhaduri Amiya Prasad
Published: March 2009

Reactions of 4‐arylidene‐3‐methyl‐5(4H)‐isoxazolones with nucleophiles lead to 4‐substituted‐benzyl‐3‐methyl‐5(2H)‐isoxazolones. Formation of 5(4H)‐ and 5(2H)‐isoxazolone derivatives have been observed when 4‐substituted‐arylidene‐3‐rriethyl‐5(4H)‐isoxazolones are reacted with methyl magnesium iodide. Oxidation of 4‐substituted‐benzyl‐3‐methyl‐5(2H)‐isoxazolones with manganic acetate and pyridinium chlorochromate, gives 4,4′‐bis[4‐substituted‐benzyl‐3‐methyl‐5(4H)‐isoxazolone]. Oxidation of 4‐substituted‐benzyl‐3‐methyl‐5(2H)‐isoxazolones with metachloroperbenzoic acid gives 4‐hydroxy‐4‐substituted‐benzyl‐3‐methyl‐5(4H)‐isoxazolones and reactions of the same substrates with N‐bromosuccinimide furnish 4‐bromo‐4‐substitutedbenzyl‐3‐methyl‐5(4H)isoxazolones.
Opioid conformations: The remarkable effect of C‐14 substituents on ring c conformations of 6α and 6β epimers of 6‐substituted epoxymorphinan opioid ligands
Authors: Crouch Ronald C. , Bhatia Ashok V. , Lever O. William
Published: March 2009

High field1H nmr studies have shown that the nature of theC‐14 substituents has a remarkable influence on ringCconformation of epoxymorphinan opioids which have a 6α‐hydroxyl group. In sharp contrast to the ringCtwist‐boat conformation observed in those 6α‐hydroxy compounds which also have a 14‐hydroxyl group (α‐naltrexol; α‐oxymorphol), ringCexists predominantly as a chair conformer in 6α‐hydroxy compounds which have a proton bound toC‐14 (dihydromorphine; dihydrocodeine). The 6β‐hydroxy compounds (β‐naltrexol; β‐oxymorphol) have a ringCchair conformation in agreement with earlier studies.
Reaction of N‐[(α‐acetoxy)‐4‐pyridylmethyl]‐3,5‐dimethylbenzamide with alkyl isocyanates
Authors: Braña Miguel F. , Castellano José M. , Donoso Rosa , López Rodríguez María L. , Yunta María J. R. , Walker Nigel P. C.
Published: March 2009

Reaction of N‐(α‐acetoxy)4‐pyridylmethyl]‐3,5‐dimethylbenzamide 3 with methyl and ethyl isocyanates afforded 1,3‐dimethyl and 1,3‐diethyl‐4‐(3,5‐dimethylbenzoylamino)‐2‐oxoimidazolidine‐5‐spiro‐4′‐[1′,4′‐dihydro‐1′‐acetyl]pyridine 6a,b, respectively. However, the reaction of 3 with isopropyl, t‐butyl and phenyl isocyanates gave the corresponding N,N′‐diurea and the dimerization compound 8. The structure of 6a was confirmed by crystal X‐ray diffraction analysis.
A novel synthetic route to 1,2‐dimethyl‐5‐phenyl‐1H‐imidazo[4,5‐b]pyridin‐7‐ol
Authors: Lis Randall , Traina Joseph A. , Huffman John C.
Published: March 2009

Heating a mixture of 4‐amino‐1,2‐dimethyl‐1H‐imidazole‐5‐carboxylic acid ethyl ester with ethyl benzoyl acetate resulted in the formation of 8‐ethoxycarbonyl‐6,7‐dimethyl‐4‐oxo‐2‐phenylimidazo[1,5‐a]pyrimidin‐5‐ium, hydroxide, inner salt. This compound was then transformed into 1,2‐dimethyl‐5‐phenyl‐1H‐imidazo‐[4,5‐b]pyridin‐7‐ol via several intermediates. A number of structurally interesting compounds were also isolated during the course of this work. Thus, the target ring system was formed by a circuitous series of ring‐chain tautomerizations/rearrangements.
Réductions chimique et électrochimique de 5H‐benzopyranno[4,3‐d]pyrimidines
Authors: Bellec Christian , Bellassoued‐Fargeau Marie‐Claude , Graffe Bernadette , Sacquet Marie‐Claude , Maitte Pierre
Published: March 2009

The chemical reduction of 5H‐[1]benzopyranno[4,3‐d]pyrimidines with lithium aluminum hydrrde leads to 3,4‐dihydro derivations. The electro‐chemical reducation in acidic medium shows two monoelectronic cathodic waves. In netural or basic medium, substituted compounds in 2 position show a single bielectronic wave while two bielectronic waves are observed for unsubstituted compounds In all cases, preparative electrolysis lead to a hydrodimer in the 4,4′‐positiom.
A novel preparation of thiazolo[5,4‐c]pyridines and the synthesis of some imidazo[4,5‐c]pyridines and oxazolo[4,5‐c]pyridines
Authors: Katner Allen S. , Brown Raymond F.
Published: March 2009

Diethoxymethyl acetate was used to cyclize o‐disubstituted aminopyridines to oxazolo[4,5‐c]pyridines and imidazo[4,5‐c]pyridines. All the possible imidazole‐methylated imidazo[4,5‐c]pyridines were prepared. A novel synthesis of 2‐substituted thiazolo[5,4‐c]pyridines and 4‐amino‐3‐pyridinethiol was discovered.
Synthesis of thiocarbonyl and heterocyclic compounds from 2‐methylene‐1,3‐dithietanes
Authors: Okajima Nobuyuki , Okada Yoshiyuki
Published: March 2009

2‐Methyl‐1,3‐dithietanes bearing electron withdrawing groups on the methylene carbon atom were synthesized and their reactivities were studied. These compounds readily underwent a ring‐opening reaction with a variety of nucleophic reagents such as amines, alcoholate and thiolate anions to yield thioamides, thionoesters and dithioesters, respectively. The products were applied for synthesis of heterocycles such as thiadiazoles, isothiazolones and pyrazoles.
Picryl derivatives of 5‐nitro‐2,4‐dihydro‐3H‐1,2,4‐triazol‐3‐one
Authors: Coburn Michael D. , Lee Kien‐Yin
Published: March 2009

Treatment of 5‐nitro‐2,4‐dihydro‐3H‐1,2,4‐triazol‐3‐one (1) with picryl fluoride (PkF) in 1‐methyl‐2‐pyrrolidinone (NMP) gave a mixture of a monopicryl and a dipicryl derivative of 1 in a ratio of 2:1, respectively, regardless of the initial concentrations of 1 and PkF. The products were identified as 5‐nitro‐2‐picryl‐2,4‐dihydro‐3H‐1,2,4‐triazol‐3‐one (2) by X‐ray crystallography and 5‐nitro‐2,4‐dipicryl‐2,4‐dihydro‐3H‐1,2,4‐triazol‐3‐one (4) by 15N labeling experiments.
A new alkaline rearrangement of the benzofuran skeleton. One step transformation of 2‐(2‐benzofuranyl)benzonitriles into (Z)‐phenylmethyleneisoindolinones
Authors: Guillaumel J. , Boccara N. , Demerseman P. , Royer R. , Bideau J. P. , Cotrait M. , Platzer N.
Published: March 2009

The alkaline hydrolysis of 2‐(2‐benzofuranyl)benzonitriles 2 by potassium hydroxide under reflux in ethanol stops at the corresponding amides 5. Using other solvents (ethylene glycol or methoxyethanol) at higher temperatures, one can obtain either the amides 5, the acids 1 or rearrangement products depending on the experimental conditions. The rearrangement products were identified as (Z)phenylmethylenedihydroisoindolinones 6 resulting from opening of the furan ring. The structures of the compounds 6 were established by 1H nmr spectroscopy (nOe) and X‐ray crystallography.
Curtius rearrangement in the 5‐phenyl‐1,4‐benzodiazepine series. Unprecedented participation by an imine nitrogen
Authors: Bock Mark G. , Dipardo Robert M. , Carson Kenneth G. , Freidinger Roger M.
Published: March 2009

The previously unknown 3‐aminomethyl‐1,3‐dihydro‐5‐(2′‐fluorophenyl)‐2H,4‐benzodiazepin‐2‐one, 3a, was synthesized in two steps as a racemate. In the chiral series, 3(S)‐azidocarbonylmethyl‐1,3‐dihydro‐5‐phenyl‐2H‐1,4‐benzodiazepin‐2‐one, 12b, was prepared from Nα‐Cbz‐β‐methylaspartate in five synthetic operations and subjected to Curtius rearrangement. The intermediate isocyanate was trapped intramolecularly by the 5‐imine nitrogen of the benzodiazepine ring in 12b. This unanticipated result runs counter to the generally held dictum that the isocyanate group has a strictly linear shape.
The synthesis and transformations of 3‐ethoxycarbonyl‐2‐isothiocyanatopyridine. Pyrido[2,3‐d]pyrimidines and some azolopyrido[2,3‐d]pyrimidines
Authors: Urleb Uroš , Stanovnik Branko , Tišler Miha
Published: March 2009

3‐Ethoxycarbonyl‐2‐isothiocyanatopyridine (2), prepared from 2‐amino‐3‐ethoxycarbonylpyridine (1) by the thiophosgene method, was converted into thiouretanes 3 and 4, 1,4‐disubstituted thiosemicarbazide 6, thioamide 8, and thioureas 15 and 18. The compounds 2 and 3 were converted into bicyclic pyrido[2,3‐d]pyrimidines 5, 9, 10, 11, 12, 16, and 17, and tricyclic azolopyrido[2,3‐d]pyrimidines 13 and 14.
Pyrolysis of azidopyrazines
Authors: Watanabe Tokuhiro , Ueda Ikuko , Hayakawa Naomi , Kondo Yasuo , Adachi Hiroko , Iwasaki Akiko , Kawamata Shizuko , Mentori Fumiko , Ichikawa Miyuki , Yuasa Kayo , Ohta Akihiro , Kurihara Teruo , Miyamae Hiroshi
Published: March 2009

2,3‐Dichloro‐ and 2,5‐dichloropyrazines were treated with sodium azide. The former gave diazidopyrazines and the latter, monoazidomonochloropyrazines. Pyrolysis of 2,3‐diazidopyrazines resulted the production of 1,2‐dicyanoiminoethanes and that of 2‐azido‐5‐chloropyrazines, chloroimidazoles.