bluuebunny/crossref_metadata_2025 huggingface dataset:
Reaction of 2‐dimethylaminomethylene‐1,3‐diones with dinucleophiles. II. Synthesis of 5‐(alkyl)(phenyl)‐4‐acylisoxazoles and 6,7‐dihydro‐1,2‐benzisoxazol‐4(5H)‐ones
Authors: Menozzi Giulia , Schenone Pietro , Mosti Luisa
Published: March 2009

The reaction of open‐chain and cyclohexane sym‐2‐dimethylaminomethylene‐1,3‐diones with hydroxylamine hydrochloride in refluxing methanol gave in good to moderate yields a series of 5‐(alkyl)(phenyl)‐4‐acylisoxazoles and 6,7‐dihydro‐1,2‐benzisoxazol‐4(5H)‐ones, respectively. As 3‐unsubstituted isoxazoles, all these compounds easily isomerized with sodium methoxide to the corresponding 2‐cyano‐1,3‐diones in high yields.
Reaction of 2‐dimethylaminomethylene‐1,3‐diones with dinucleophiles. III. Synthesis of 5‐acylpyrimidines and 7,8‐dihydroquinazolin‐5(6H)‐ones
Authors: Mosti Luisa , Menozzi Giulia , Schenone Pietro
Published: March 2009

The reaction of open‐chain and cyclohexane sym‐2‐dimethylaminomethylene‐1,3‐diones with amidines and guanidine in refluxing ethanol gave, generally in good yields, a series of 5‐acylpyrimidines and 7,8‐dihydroquinazolin‐5(6H)‐ones, respectively. With formamidine (and in part acetamidine), 2‐formylimino‐1,3‐diones were formed in general, as sole products or mixtures with the corresponding pyrimidines or dihydroquinazolinones.
Addition photochimique d'azidoformiate d'alkyle sur le méthylène‐2 tétrahydropyranne et le méthoxy‐2 dihydro‐5,6 γ‐pyranne
Authors: Kozlowska‐Gramsz Elzbieta , Descotes Gérard
Published: March 2009

La régiosélectivité et la stéréosélectivité de l'addition photochimique des nitrènes et de l'alcoolyse ou de l'hydrolyse des aziridines intermédiaires sont étudiées sur 1 et 2. Ces réactions sont régiospécifiques et fortement stéréosélectives pour conduire à des aminocétals ou des aminocétals dont les structures ont été établies.
Voies d'accès à un analogue pyrannique de la puromycine
Authors: Carret Geneviève , Sarda Nicole , Abou‐Assali Mounir , Anker Daniel , Pachéco Henri
Published: March 2009

L'obtention de l'analogue pyrannique 3 de la puromycine 1 via l'aminonucleoside 4 est réalisée à partir des anhydro‐2,3‐désoxy‐4‐α et β‐D,L‐érythro‐pentopyranosides de méthyle (12). La première voie consiste à introduire la fonction amine et à réaliser les isomérisations nécessaires à l'obtention de la stéréochimie érythro de la partie osidique avant de réaliser la liaison N‐glycosidique avec la purine; elle comporte 9 étapes pour arriver à l'aminonucleoside 4 (34% à partir de 12β). Par la deuxième voie, on réalise les modifications chimiques et structurales de la partie osidique après la création de la liaison N‐glycosidique; cette deuxième voie comporte 9 étapes (37% à partir du mélange 12α et 12β).

L'introduction de la L‐O‐méthyltyrosine convenablement protégée est réalisée par le “BOP” et les deux diastéréoisomères obtenus conduisent après déblocage, aux deux diastéréoisomères cherchés 3A et 3B qui sont séparés sur colonne de gel de silice.
Racematspaltung von (±)‐5‐äthyl‐1‐(3,4‐dimethoxyphenyl)‐6,7‐dimethoxy‐4‐methyl‐5H‐2,3‐benzodiazepin und anomales chiroptisches verhalten der enantiomeren
Authors: Tóth Gábor , Fogassy Elemér , Ács Mária , Töke László , Láng Tibor
Published: March 2009

Es wurde ein Verfahren für die Racematspaltung von 1 entwickelt. Das anomale Verhalten des spezifischen optischen Drehungsvermögen der Enantiomere wurde untersucht, und es wurde bewiesen, dass es nicht auf die Epimerisation des C‐5 Atoms, sondern auf die Verschiebung des Konformationsgleichge‐wichtes 1a ← 1b zurückzuführen ist.
A facile synthesis of 1,3,4‐selenadiazolo[2,3‐b]quinazoline derivatives via japp‐klingemann reaction
Authors: Abdelhamid Abdou O. , Hassaneen Hamdi M. , Shawali Ahmad S.
Published: March 2009

Diazotized anthranilic acid and its methyl ester react with ethyl α‐selenocyanatoacetate 3a and α‐selenocyanatoacetoacetanilide 3b to give in both cases the corresponding 1,3,4‐selenadiazolo[2,3‐b]quinazoline derivatives 7a and 7b, respectively, in good yields (70‐80%). A mechanism is proposed and it is substantiated by an alternate synthesis of 7a and 7b from the corresponding hydrazidoyl chlorides 9a and 9b with potassium selenocyanate, respectively. An evidence for the involvement of the 1,3,4‐selenadiazoline derivative as an intermediate in these reactions is provided by the isolation of 11 from either coupling of 3b with diazotized ethyl p‐aminobenzoate or the reaction of hydrazidoyl chloride 12 with potassium selenocyanate.
On the possibility of isolating diazirine N‐oxides
Authors: Boyd Russell J. , Gupta Abha
Published: March 2009

Ab initio molecular orbital calculations at the 6‐31G level predict that diazirine N‐oxide is more stable with respect to its constituent fragments, singlet CH2 and N2O2, than diazirine is with respect to singlet CH2 and N2. In view of these results and the many diazirines which have been reported, it is suggested that it may be possible to detect a suitably substituted diazirine N‐oxide.
Synthesis of 2‐arylpyrido[3,4‐b]pyrazine derivatives through condensation of 3,4‐diaminopyridine with β‐keto sulfoxides
Authors: Kano Shinzo , Yuasa Yoko
Published: March 2009

The reaction between 3,4‐diaminopyridine and α‐methylsulfinylacetophenone in benzene containing acetic acid under reflux gave 2‐phenylpyrido[3,4‐b]pyrazine. In this way, 2‐(4‐methoxyphenyl)pyrido[3,4‐b]‐pyrazine and 2‐(3,4‐dimethoxyphenyl)pyrido[3,4‐b]pyrazine were obtained by condensation of 3,4‐diaminopyridine with the corresponding α‐methylsulfinylacetophenones.
Facile synthesis of N‐substituted‐4‐cyano‐4‐phenylpiperidines via phase‐transfer catalysis
Authors: Thompson Doug , Reeves Perry C.
Published: March 2009

Phenylacetonitrile can be condensed with N‐substituted‐bis(2‐chloroethyl)amines in aqueous sodium hydroxide solution to produce N‐substituted‐4‐cyano‐4‐phenylpiperidines. Hexadecyltributylphosphonium bromide is an effective catalyst for this phase‐transfer reaction.
Selective synthesis of the two diastereomers of 5‐oxo‐1H‐pyrrolizine‐3‐carboxylic acid
Authors: Turner William W.
Published: March 2009

The rhodium catalysed reduction of a 2,5‐disubstitued pyrrole 5 occurred selectively with the cis addition of hydrogen. The resulting cis‐pyrrolidine was either cyclized without epimerization in refluxing toluene to the pyrrolizine 7 or with epimerization in refluxing acetic acid to the pyrrolizine 9.
On the formation of “symmetrical” phenoxazinone derivative related to the actinomycin D chromophore
Authors: Sehgal Raj K. , Sengupta Sisir K. , Dieter R. Karl
Published: March 2009

In studies related to the synthesis of 2‐deamino chromophores of actinomycin by reaction of nitrous acid in fluoroboric acid via diazotization of the 2‐amino group in the chromophore, the unknown fluorescent product is identified as the symmetrical phenoxazinone by cmr and pmr.
Synthesis of 6‐arylazo‐substituted 5‐hydroxy‐2‐hydroxymethyl‐4‐pyridones and related compounds
Authors: Imafuku Kimiaki , Matsuura Hiromichi
Published: March 2009

5‐Hydroxy‐2‐hydroxymethyl‐4‐pyridone (1) and 5‐hydroxy‐2‐hydroxymethyl‐1‐methyl‐4‐pyridone (2) reacted with arenediazonium salts to give 6‐arylazo‐substituted compounds 3a‐d and 4a‐d, respectively. Compounds 3a‐d were methylated with diazomethane to afford 6‐arylazo‐2‐hydroxymethyl‐4,5‐dimethoxypyridines 5a‐d.
Ring transformation reactions of C‐nucleosides: Facile synthesis of pyrazolo[1,5‐a]pyrimidine and pyrazolo[1,5‐a]triazine C‐nucleosides
Authors: Chu C. K. , Suh J. J. , Mesbah M. , Cutler S. J.
Published: March 2009

1,3‐Dimethyluracil (1), a versatile synthon for the synthesis of various heterocycles, reacted readily with 3‐aminopyrazoles 2 in sodium ethoxide to give pyrazolo[1,5‐a]pyrimidines 3. Under similar conditions, 3‐aminopyrazole C‐nucleosides 4 and the synthon 1 gave a mixture of pyrazolo[1,5‐a]pyrimidine C‐nucleosides, which was separated on a silica gel column. Attempts to remove the protecting groups yielded pyranose derivative 10. Another synthon 1,3‐dimethyl‐5‐azauracil and 3‐aminopyrazoles 12 gave pyrazolo[1,5‐a]triazines 13. In a similar reaction with 3‐aminopyrazole C‐nucleosides 4 gave the corresponding pyrazolo[1,5‐a]‐triazine C‐nucleosides 14 and 15.
Synthesis of substituted pyrrolo[1,2‐a][1,3]diazepine. A correction
Authors: Zimmermann Werner , Sinambela James M. , Roth Herman J. , Eger Kurt
Published: March 2009

The structure of a formerly described pyrrol[1,2‐a][1,3]diazepine is corrected by synthesis. The correction is discussed by comparing physicochemical data and synthetic procedures for both substances.
Novel syntheses of 3‐cyano‐3,4‐dihydroquinolin‐2(1H)‐one and derivatives of 2,3‐dicarbomethoxy‐2‐hydroxycyclopenta[b]quinoline
Authors: Neelima  , Bhat Balkrishen , Bhaduri Amiya Prasad
Published: March 2009

A facile solid phase conversion of 2‐chloro‐3‐cyano‐4‐substituted‐1,4‐dihydroquinolines to 3‐cyano‐4‐substituted‐3,4‐dihydroquinolin‐2(1H)‐ones in almost quantitative yields and a novel synthesis of 2,3‐dicarbomethoxy‐2‐hydroxycyclopenta[b]quinoline are described.
Benzohydrazides, benzothiohydrazides, and benzamidrazones as sources of 1,3,4(2H)‐oxadiazolenones, 1,3,4(2H)‐thiadiazolenones, and 1,2,4(5H)‐triazolenones
Authors: Barnish Ian T. , Fung Shing C. , Gibson Martin S. , Khan Saeed R. , Pawalchak Gordon A. , Tse Kin M.
Published: March 2009

Benzohydrazides, benzothiohydrazides, and benzamidrazones have been converted to 1,3,4(2H)‐oxadiazolenones, 1,3,4(2H)‐thiadiazolenenones, and 1,2,4(5H)‐triazolenones respectively by reaction with ethyl chloroformate, with ethyl thiolchloroformate, and with phenyl isocyanate. In some reactions, a carbamate or urea has been isolated as intermediate.
Solid‐state structures of cis‐ and trans‐1‐cyclohexyl‐2‐phenyl‐3‐(p‐toluyl)aziridines
Authors: Tarburton John Philip , Day Cynthia S. , Day Victor W. , Tavaniepour Iraj , Cromwell Norman H.
Published: March 2009

Solid‐state structures have been determined for cis‐ and trans‐1‐cyclohexyl‐2‐phenyl‐3‐(p‐toluyl)aziridines using single‐crystal X‐ray diffraction techniques. The cis isomer crystallizes in the centrosymmetric monoclinic space group P21/c (No. 14), with a = 18.669(3)Å, b = 5.709(1)Å, c = 17.412(2)Å, β = 96.29(1)° and Z = 4; the trans isomer crystallizes in the noncentrosymmetric orthorhombic space group Pna21 (No. 33), with a = 17.089(2)Å, b = 18.729(3)Å, c = 5.749(1)Å and Z = 4. Full‐matrix least‐squares refinement of the structural parameters led to the following final agreement factors: R1 (unweighted, based on F) = 0.040 and R2 (weighted, based on F) = 0.054 for the 2592 independent reflections of the cis isomer having 2θMoK¯α <55° and I>3σ1, and R1 = 0.033 and R2 = 0.031 for the 1504 independent reflections of the trans isomer having 2θMoK¯α <55° and I>3σ1. The statistically significant differences that exist between the two isomers for two bond lengths and ten bond angles (p < 0.05) appear to be the direct result of the p‐toluyl group orientation with respect to the cyclohexyl and phenyl substituents. In the cis isomer it is anti with respect to the N‐cyclohexyl group and cis with respect to the phenyl group, whereas in the trans isomer it is syn with respect to the N‐cyclohexyl and trans with respect to the phenyl group. Three‐ring to carbonyl hyperconjugation is correlated with stereoelectronic interactions in the trans isomer. Bonding, determined by X‐ray and nmr studies, is discussed for the three‐membered aziridine ring proper; while bonding, determined by X‐ray studies, is discussed for substituents of the aziridine ring. These aziridinyl ketone compounds are of importance as potential mammalian DNA alkylating anti‐tumor agents in solid‐state solid‐state systems. To date only a trans isomer has demonstrated this biological activity in tumor‐bearing rats.
Mass spectral study of 2‐aryl‐4‐arylhydrazono‐4,5,6,7‐tetrahydro‐2H‐benzo‐1,2,3‐triazoles
Authors: Lefkopoulou S. , Theodosiou M. , Stephanidou‐Stephanatou J. , Alexandrou N. E.
Published: March 2009

The mass spectra upon electron impact at 70 eV of the title compounds are examined. The fragmentation pattern of the tetrahydro‐benzotriazoles with unsymmetrically substituted the aryl groups in 2‐position and in hydrazone group cannot support the aspect for a mononuclear heterocyclic rearrangement.
Reaction of ketenes with N,N‐disubstituted α‐aminomethyleneketones. XVII. Synthesis of 2H‐[1]benzothiepino[5,4‐b]pyran derivatives
Authors: Menozzi Giulia , Mosti Luisa , Schenone Pietro
Published: March 2009

1,4‐Cycloaddition of dichloroketene to a number of N,N‐disubstituted (E)‐4‐amino methylene‐3,4‐dihydro‐[1]benzothiepin‐5(2H)‐ones gave in excellent yield N,N‐disubstituted 4‐amino‐3,3‐dichloro‐3,4,5,6‐tetrahydro‐2H‐[1]benzothiepino[5,4‐b]pyran‐2‐ones III, which are derivatives of the 2H‐[1]benzothiepino[5,4‐b]pyran system. Dehydrochlorination of III with DBN afforded N,N‐disubstituted 4‐amino‐3‐chloro‐5,6‐dihydro‐2H‐[1]‐benzothiepino[5,4‐b]pyran‐2‐ones, generally in excellent yield.
Studies directed toward the synthesis of conformationally restricted neurotransmitter analogs: The addition of N‐hydroxyimides to ethyl propiolate
Authors: Breaux E. Jay
Published: March 2009

N‐Hydroxyimides were found to add readily to ethyl propiolate to yield the imidooxyacrylates in both protic and aprotic solvents. The trans isomer only was formed in aprotic solvents while both isomers were formed in protic solvents.
Chemical reactions of cycloalkanespirohydantoins. Part 3. Acid‐catalyzed reaction of 4‐hydroxy‐2‐imidazolidinones. Preparation of bis(1,3‐diaza‐2‐oxospiro[4,5]decyl‐4) ether
Authors: Pedregal Carmen , Espada Modesta , Salazar Loreto , Elguero José
Published: March 2009

The use of N‐carbamoyliminium ion initiated reactions for the generation of spiroimidazolidin‐2‐ones has been successfully exploited. N3‐Substituted‐4‐hydroxy‐2‐imidazolidinones have been treated under acid conditions to give the rearranged imidazolinones. Only in the case of N3‐dialkylaminomethyl‐4‐hydroxy‐5‐cyclohexanespiro‐2‐imidazolidinones upon treatment with trifluoroacetic anhydride/trifluoroacetic acid afforded a mixture containing bis(1,3‐diaza‐2‐oxospiro[4,5]decyl‐4) ether with the rearranged imidazolidinone.
Preparation of 5,5‐dicyano‐ and 5‐cyano‐5‐ethoxycarbonyl‐5,6‐dihydro‐3,7‐diphenyl‐4H‐1,2‐diazepines and their halogenations
Authors: Kamata Kichinosuke , Tsuge Otohiko
Published: March 2009

5,5‐Dicyano‐ and 5‐cyano‐5‐ethoxycarbonyl‐5,6‐dihydro‐3,7‐diphenyl‐4H‐1,2‐diazepines were prepared by the condensation of α‐bromoacetophenone azine with malononitrile and ethyl cyanoacetate in the presence of sodium ethoxide, respectively. Halogenations of the dihydrodiazepines gave pyridazines, diazanorcaradienes, 4,4,6,6‐tetrachlorodihydrodiazepines, and/or a 4‐chloropyrazole whose relative yields strongly depended upon the nature of 5‐substituents of the dihydrodiazepines as well as the reaction conditions.
2‐Alkoxy‐3‐substituted‐4‐quinolinols from the thermal reactions of N‐phenylketenimines bearing ester groups
Authors: Motoyoshiya Jiro , Takagi Akira , Hirakawa Kiyoichi , Kakurai Toshio
Published: March 2009

Several ketenimines bearing ester groups were prepared and their thermal reactions gave 2‐alkoxy‐3‐substituted‐4‐quinolinols VIa‐e via presumed iminoketene intermediates. Subsequent oxidation of 2‐alkoxy‐3‐(3‐methylbut‐2‐enyl)‐4‐quinolinols VIc and VId provided pyranoquinolines VIIIa and VIIIb.
Amination of 4‐nitropyridazine 1‐oxides by liquid ammonia/potassium permanganate
Authors: Tondys Hanna , Plas Henk C. Van Der
Published: March 2009

Treatment of 4‐nitropyridazine 1‐oxide (1a) 3‐methoxy‐6‐chloro‐4‐nitropyridazine 1‐oxide (1b) or 3,6‐dimethoxy‐4‐nitropyridazine 1‐oxide (1c) with a solution of potassium permanganate in liquid ammonia gives in reasonable‐to‐good yields the corresponding 5‐amino‐4‐nitropyridazine 1‐oxides (75%, 54% and 62%, respectively). 3,6‐Dimethoxypyridazine (4a) and 3‐methoxypyridazine (4b) are converted into the corresponding 4‐aminopyridazines 6a,6b on treatment with potassium amide/liquid ammonia/potassium permanganate (yield 50 and 22% respectively). In the last‐mentioned reaction besides 6b 3,3′‐dimethoxy 4,4′‐bipyridazine (7, 23%) was obtained. It is suggested that the neutral 1:1 σ‐adducts formed between (1a–1c) and liquid ammonia and the anionic σ‐adducts, formed between (5a–5b) and potassium amide are intermediates in this amino‐oxidation reaction.
Regioselective alkylation of guanine via diacyloxyglyoxal‐N2‐acetylguanine adduct to obtain 7‐alkylguanine derivatives. Studies on alkylation of guanine I
Authors: Kjellberg Jonas , Johansson Nils Gunnar
Published: March 2009

The acylated guanine‐glyoxal adduct (I) has been alkylated with 4‐bromobutyl acetate and in the presence of sodium hydride the reaction was regioselective to give 7‐alkylguanine.
A convenient synthesis of 3‐formyl‐2‐oxo‐1,2‐dihydroquinoxaline chlorophenylhydrazones: Novel tautomeric equilibria between hydrazone imine and diazenyl enamine forms with long‐range pSSrototropy
Authors: Kurasawa Yoshihisa , Yamazaki Kaoru , Tajima Setsuko , Okamoto Yoshihisa , Takada Atsushi
Published: March 2009

3‐Formyl‐2‐oxo‐1,2‐dihydroquinoxaline chlorophenylhydrazones 4a‐c were synthesized from the reactions of 3‐methyl‐2‐oxo‐1,2‐dihydroquinoxaline 3 with chlorophenyl diazonium salts, and 4b,c were found to exhibit the tautomeric equilibria between the hydrazone imine and diazenyl enamine forms in the dimethylsulfoxide solutions.
Imino‐bridged heterocycles. VI . An unusual bridge structure resulting from an attempted ritter reaction in the benzo[5,6]cyclohepta[1,2‐c]pyridine system
Authors: Reamer Robert A. , Brenner Daniel G. , Shepard Kenneth L.
Published: March 2009

An attempt to generate a tertiary carbinamine from 1, through use of the Ritter reaction, resulted in the formation of the new bridged system 2. This product apparently resulted from an intramolecular cyclization of the 5,6 olefin to the C‐11 nitrilium ion of 4, followed by a second Ritter reaction at C‐6.
Formation of a tricyclic nucleoside from deoxyguanosine via an O6‐N1‐transposition
Authors: Maggio A.‐F. , Lucas M. , Barascut J.‐L. , Imbach J.‐L.
Published: March 2009

The synthesis of a tricyclic deoxynucleoside by reaction of β‐substituted ethanols with an activated deoxyguanosine is described. Its formation is rationnalised by an O6‐N1‐transposition.
Novel heterocycles. 13 Synthesis of 5,6‐dihydro‐1H‐3H‐pyrrolo[3,2,1‐ij][3,1]benzoxazine‐1,3‐dione
Authors: Coppola Gary M. , Palermo Stephen
Published: March 2009

The synthesis of 5,6‐dihydro‐1H,3H‐pyrrolo[3,2,1‐ij][3,1]benzoxazine‐1,3‐dione (2a), a new ring system, from N‐acetylindoline is described.
Hexahydro‐5,6,6a,7,12,14 isoquino[2,3‐b]benzazépine‐2. Nouvelle voie d'accès
Authors: Hénin Jacques , Gardent Jean
Published: March 2009

Plusieurs hexahydro isoquino[2,3‐b]benzazépines‐21b‐ediversement substituées en positions 9,10,11 par des groupements alkoxy ont été préparées par une cyclisation de type Pictet‐Spengler à partir de formaldéhyde et d'alkoxybenzyl‐3 tétrahydro‐2,3,4,5 1Hbenzazépines‐212b‐e. Les nouveaux composés préparés n'ont pas montré d'activité antitumorale in vitro sur des cellules de la ligneé L 1210.
Action des hydrazines sur les acétyl‐4 chloro‐5 (ou 3) méthyl‐3 (ou 5) pyrazoles: Formation d'une pyrazolo[3,4‐b]quinoléïne, d'hydrazones et de cétazines
Authors: Gonzalez Emmanuel , Elguero José
Published: March 2009

On discute les caractéristiques que doivent posséder les hydrazones d'acétyl‐4 chloro‐5 (ou 3) pyrazoles pour se cycliser en pyrazolo[3,4‐c]pyrazoles à la lumière des échecs obtenus avec les N‐méthylpyrazoles et les phénylhydrazones. Au lieu des dérivés de l'aza‐1 pentalène on a isolé une nouvelle pyrazolo[3,4‐b]quinoléïne, des hydrazones et des cétazines.
Imination of N‐methylpyridinium salts by liquid ammonia‐potassium permanganate. A new synthesis of nudiflorine
Authors: Buurman D. J. , van der Plas H. C.
Published: March 2009

Reaction of substituted 1‐methyl(benzyl)pyridinium salts (1) with liquid ammonia/potassium permanganate leads to introduction of the imino group at the carbon adjacent to the nitrogen. The regiospecificity of the reaction strongly depends on substituent X: at C‐6 for X = H, CONH2, C6H5 and at C‐2 for X = CH3. 3‐Aminocarbonyl‐1‐t‐butylpyridinium iodide (5) on treatment with liquid ammonia/potassium permanganate exclusively gives the 4‐imino compound 8; 1H nmr spectroscopy shows that 5 in liquid ammonia gives a mixture of the σ‐adducts 4‐amino‐1,4‐dihydro‐ and 6‐amino‐1,6‐dihydro‐3‐pyridinecarbonamide (6 and 7). Surprisingly, an oxodemethylation reaction is observed on treatment of 3‐aminocarbonyl‐1,6‐dimethylpyridinium iodide (13) with liquid ammonia/potassium permanganate, 1,6‐dihydro‐1‐methyl‐6‐oxo‐3‐pyridinecarboxamide (14) being obtained. This compound can easily be converted by phosphorus oxychloride into the alkaloid nudiflorine (15).
New substituted 4‐azatricyclo[4.3.1.13,8]undecane derivatives
Authors: Georgiev Vassil St. , Saeva Grace A. , Kinsolving C. Richard
Published: March 2009

The synthesis of a series of new substituted 4‐azatricyclo[4.3.1.13.8]undecane and 4‐azatricyclo[4.3.1.13.8]‐undecan‐5‐one derivatives is described. Compounds 4f and 4g displayed antiviral activity.
Research on heterocyclic compounds. XX. Synthesis of trifluoromethyl derivatives of fused imidazole systems
Authors: Abignente Enrico , de Caprariis Paolo , Patscot Rosaria , Sacchi Antonella
Published: March 2009

A series of heterocyclic compounds having an imidazole ring fused with another ring with a bridgehead nitrogen atom and bearing a trifluoromethyl moiety was synthesized by reaction of 3‐bromo‐1,1,1‐trifluoroacetone with various heteroarylamines. In some cases, an intermediate compound obtained together with the required product was isolated and its structure was elucidated: e.g., starting from 2‐aminopyridine we have obtained 2‐trifluoromethylimidazo[1,2‐a]pyridine and 2‐hydroxy‐2‐trifluoromethyl‐2,3‐dihydro‐1H‐imidazo [1,2‐a]pyridinium bromide. Such results confirmed the mechanism previously proposed for this reaction.
Action du phényllithium en série pyrazine: Piégeage des intermédiaires réactionnels par le benzoate de méthyle
Authors: Mettey Yvette , Vierfond Jean‐Michel
Published: March 2009

L'action du phényllithium sur la pyrazine, la méthyl pyrazine et l'acétonyl pyrazine conduit à des produits d'addition sur une ou sur deux liaisons iminiques du noyau pyrazine. L'addition de benzoate de méthyle au milieu réactionnel entraîne la formation de produits C ou N condensés à partir des intermédiaires lithiés formés. Nous n'avons pas isolé de produits issus d'une métallation des chaînes latérales (‐ CH3 ou ‐CH2COCH3).
Synthesis of some new pyrimido[1,6‐a]pyrimidines. Isolation of stable covalent hydrated pyrimido[1,6‐a]pyrimidines
Authors: Pegiadou‐Koemtjopoulou S.
Published: March 2009

4‐Amino‐5‐phenylpyrimidine2reacts with alkyl malonic acids3in acetic anhydride under reflux to give 2(4)H‐pyrimido[1,6‐a]pyrimidines4.From these reactions some covalent hydrated pyrimido[1,6‐a]pyrimidines5were also isolated, where the addition of the water molecule occurred to the 6,7 C = N bond. This covalent hydration is irreversible.
Synthesis of (pyridinyl)‐1,2,4‐triazolo[4,3‐a]pyridines
Authors: Moran Daniel B. , Morton George O. , Albright J. Donald
Published: March 2009

Methods for the synthesis of (pyridinyl)‐1,2,4‐triazolo[4,3‐a]pyridines were developed. The principal route to the required intermediate 2‐chloropyridines was based on rearrangements of mono N‐oxides of 2,2′‐bipyridine, 2,3′‐bipyridine, 3,3′‐bipyridine, 2,4′‐bipyridine and 4,4′‐bipyridine with phosphorus oxychloride. Reaction of 3,3′‐bipyridine 1‐oxide or 2,2′‐bipyridine 1‐oxide with phosphorus oxychloride gave mixtures of chloro isomers. Reaction with acetic anhydride, 3,3′‐bipyridine 1‐oxide and 2,2′‐bipyridine 1‐oxide gave exclusively [3,3′‐bipyridine]‐2(1H)‐one and [2,2′‐bipyridine]‐6(1H)‐one, respectively.

1,2,4‐Triazolo[4,3‐a]pyridines with pyridinyl groups at the 5,6,7 and 8 positions were synthesized.
Cycloaddition reactions of benzothiete with azomethines
Authors: Jacob Dominic , Meier Herbert
Published: March 2009

A new synthetic route to 3,4‐dihydro‐2H‐1,3‐benzothiazines 5 has been developed by the regiospecific cycloaddition of Schiff bases 4 and benzothiete 1, which is primarily opened by heating to the corresponding o‐quinoidal form 2.
A controlled‐oxidation synthesis of substituted aryl 1‐methyl‐4‐nitro‐5‐imidazolyl sulfones
Authors: Heindel Ned D. , Lacey C. Jeffrey , Egolf Roger , Mease Belle N. , Schray Keith J.
Published: March 2009

Aryl imidazolyl sulfones bearing pendant hemisuccinamido groups for conjugation to biopolymer transport systems were synthesized from sulfide precursors. The peroxide‐effected oxidation at sulfur was invariably accompanied by some cleavage‐oxidation of the carboxamido groups to nitro functionalities, a process which could be minimized by careful control of the reaction conditions.
Autoxidation of nitrogen heterocycles. 3. Solvent effects in the autoxidation of 2,5‐dimethylpyrrole
Authors: Beaver Bruce D. , Cooney John V. , Watkins John M.
Published: March 2009

The mechanism of the autoxidation of C‐alkylpyrroles is suggested to proceed by way of a charge transfer mechanism. Kinetic measurements for the autoxidation of a representative C‐alkylpyrrole, 2,5‐dimethylpyrrole, are presented which are consistent with this hypothesis.
Fragmentation and isomerization reactions of phenyl substituted 2‐oxo‐1,3,2‐dioxathianes (trimethylene sulfites)
Authors: Olsen Robert J. , Lewis Timothy A. , Mehta Manish A. , Stack Jeffrey G.
Published: March 2009

The preparation and Grob‐like fragmentation of several phenyl substituted 2‐oxo‐1,3,2‐dioxathianes (trimethylene sulfites) have been examined. Preparation of the 4,4,6‐triphenyl derivatives gives a chair S = O equatorial isomer which fragments readily in polar solvents to produce benzaldehyde and 1,1‐diphenylethylene. Isomerization to an unreactive twist boat isomer occurs as a minor reaction in solution and in the solid state on prolonged storage. Activation parameters and substituent effects on the fragmentation reaction are consistent with an ionic mechanism. The diphenyl derivatives react only in the presence of boron trifluoride etherate giving mainly isomerization to the stable chair, S = O axial form; fragmentation is a minor pathway.
Synthesis and reactions of α‐ketoaldehyde adducts of some heterocyclic ureas
Authors: Hough T. L. , Hough I. R. , Pannell R. W.
Published: March 2009

Pyruvaldehyde reacts with heterocyclic ureas 4a‐d giving dihydroxyimidazolidin‐2‐ones 5a‐d. Phenyl glyoxal reacts with 4a giving an analogous adduct 5e. These 1,2‐diols are smoothly dehydrated to hydantoins 9a‐e which on mild reduction provide monohydroxyimidazolidin‐2‐ones 10a‐e. Cis and trans isomers of 10d have been isolated and observed to epimerise under suitable conditions. An unusual halogenation converts 5a to the bromomethyl derivative 14b which is a convenient starting material for the synthesis of 4‐substituted imidazolin‐2‐ones such as 15, 16, 17, 18 and 19.
Synthesis and crystal structure of 5‐methyl‐5,10‐dihydrophenarsazine
Authors: de Meester Patrice , Chu Shirley S. C. , Jovanovic Misa V. , Biehl Edward R.
Published: March 2009

The X‐ray crystal structure of 5‐methyl‐5,10‐dihydrophenarsazine, C13H12NAs, has been determined. The crystals are orthorhombic, space group P212121, a = 8.511(4), b = 5.690(1), c = 23.535(9) Å, V = 1139.7(1.0)A3, and Z = 4. Least‐squares refinement converged to R = 0.049 and Rw = 0.045. The central ring is in a boat conformation and the 5‐methyl group is in the axial position with respect to the central ring. The folding angle between the planes of the two benzo rings is 154.1(4)°.
Cycloaddition reactions of ketoimines. Part II. Synthesis of substituted phenanthridines and cyclopenta[c]quinolines
Authors: Lucchini Vittorio , Prato Maurizio , Scorrano Gianfranco , Tecilla Paolo
Published: March 2009

Substituted 4‐benzoyl‐3a,4,5,9b‐tetrahydro‐3H‐cyclopenta[c]quinolines 3 and 6‐benzoyl‐5,6,6a,7,8,10a‐hexahydrophenanthridines 10 are obtained through Lewis acid catalyzed addition of 1‐phenyl‐2‐arylamino‐2‐methoxyethanones 2 to cyclopentadienes and 1,3‐cyclohexadiene respectively. Compounds 3 can be converted to the aromatized analogues by reaction with 2,3‐dichloro‐5,6‐dicyanobenzoquinone in refluxing benzene. Compounds 10 are oxidized by sulfur either in decalin or in quinoline to substituted 6‐benzoylphenanthridines.
Synthèse et caractérisation d'une série de bis‐9,9′(thio‐9‐acridinyl)‐α,ω‐alcanes
Authors: Poulallion Pierre , Galy Jean‐Pierre , Vincent Emile‐Jean , Galy Anne‐Marie , Barbe Jacques , Atassi Ghanem
Published: March 2009

Une méthode rapide de préparation de composés diacridiniques soufrés pontés en position 9,9′, est décrite. Le pontage est réalisé par des dihalogénoalcanes en utilisant la catalyse en transfert de phase. Les caractéristiques physicochimiques de 61 composés, en particulier leurs paramètres de rmn du 1H et du 13C, sont présentées.
2‐Methylpyridinium salts as 1,4‐dinucleophiles. II. Westphal condensation with substituted pyridinium substrates
Authors: Ezquerra J. , Alvarez‐Builla J.
Published: March 2009

Condensation of α‐methylpyridinium, quinolinium and isoquinolinium salts with 1,2‐dicarbonyls in the presence of base, yielded quinolizinium derivatives. In an analogous process, α‐benzyl derivatives produced 2,3‐dihydroindolizin‐2‐ones by intramolecular cyclisation.
Remarkable substituent effects found in the base‐catalyzed reaction of 5‐methyl‐2‐(4′‐substituted‐phenyl)‐2,4‐dihydro‐3H‐pyrazol‐3‐ones
Authors: Matsugo Seiichi , Takamizawa Akira
Published: March 2009

Remarkable substituent effects found in the base‐catalyzed reaction of 5‐methyl‐4‐(1‐methylethylidene)‐2‐(4′‐substituted‐phenyl)‐2,4‐dihydro‐3H‐pyrazol‐3‐ones (2) with acetone at reflux are described.
Novel syntheses of 2,3‐dihydro‐5H‐1,4‐benzoxathiepins and 1,2,3,5‐tetrahydro‐4,1‐benzothiazepines
Authors: Ishibashi Hiroyuki , Okada Motofumi , Akiyama Atsuko , Nomura Kazuyuki , Ikeda Masazumi
Published: March 2009

2,3‐Dihydro‐5H‐1,4‐benzoxathiepins were prepared by intramolecular Friedel‐Crafts reactions of ethyl α‐[2‐(aryloxy)ethylthio]‐α‐chloroacetates or by acid‐catalyzed cyclizations of ethyl α‐[2‐(aryloxy)ethylsulfinyl]‐acetate. 1,2,3,5‐Tetrahydro‐4,1‐benzothiazepines were similarly prepared.
Potential cerebral perfusion agents. Synthesis and evaluation of berberine analogues
Authors: Srivastava Prem C. , Tedjamulia Marvin L. , Knapp Furn F.
Published: March 2009

The synthesis and tissue distribution studies in rats of tetra[3H]‐hydroberberine ([3H]2) and 8‐(p‐[125I]iodobenzyl)tetrahydroberberine ([125I]6) are described. Compound 2 was synthesized by sodium borohydride reduction of berberine hydrochloride (1). Treatment of berberine hydrochloride with p‐bromo‐benzylmagnesium bromide gave 8‐(p‐bromobenzyl)dihydroberberine (4) which after sodium borohydride reduction and iodine‐125 bromine exchange gave [125I]6. The unsubstituted tetrahydro compound [3H]2 showed significantly higher brain uptake (2.2% dose/gm after 5 minutes) as compared to the corresponding 8‐substituted derivative [125I]6. Both radiolabeled compounds washed out from the brain relatively quickly.
Synthesis of 2‐aryl‐6‐carbethoxythiazolo[4,5‐c]pyridine and 7‐chloro‐2‐phenylthiazolo[5,4‐c]pyridine
Authors: Shafiee A. , Ghazar H.
Published: March 2009

Starting from readily available 2‐aryl‐5‐formyl‐4‐mehtylthiazole, 2‐aryl‐6‐carbethoxythiazolo[4,5‐c]pyridine was prepared. β‐(2‐Phenylthiazol‐4‐yl)acrylic acid was converted to the corresponding azide (VI). Cyclization of compound VI afforded 2‐phenylthiazolo[5,4‐c]pyridin‐7(6H)one. Reaction of the latter with phosphorous oxychloride gave 7‐chloro‐2‐phenylthiazolo[5,4‐c]pyridine.
Heterocyclic rearrangements. Synthesis of 1,2,4‐oxadiazolo[2,3‐a]pyrimidinium systems and their ring opening into pyrimidine N‐oxides
Authors: Buscemi Silvestre , Macaluso Gabriella , Frenna Vincenzo , Vivona Nicolò
Published: March 2009

The reaction of 3‐amino‐5‐phenyl‐(methyl‐)‐1,2,4‐oxadiazole with acetylacetone or benzoylacetone in the presence of perchloric acid has been studied. Synthesis of 1,2,4‐oxadiazolo[2,3‐α]pyrimidinium perchlorates and their ring opening reaction into aminopyrimidine N‐oxides is reported.
Synthesis of 9‐(2‐fluorobenzyl)‐6‐methylamino‐9H‐purine
Authors: Kelley James L. , McLean Ed W.
Published: March 2009

Synthesis of 9‐(2‐fluorobenzyl)‐6‐methylamino‐9H‐purine (1) from nine different precursors is reported. Compound 1 was prepared by methylamination of 6‐chloro‐9‐(2‐fluorobenzyl)‐9H‐purine (4), by alkylation of 6‐methylaminepurine (5) or form 9‐(2‐fluorobenzyl)‐1‐methyladeninium iodide (8) via the Dimroth rearrangement. Selective 2‐step methylation of 6‐aminopurine 6 was accomplished by hydride reduction of 6‐formamidopurine 9, 6‐dimethylaminomethyleneaminopurine 10 or 6‐phenylthiomethyl purine 11 to give 1. Compound 1 was also prepared by dethiation or reductive dechlorination of 2‐methylthiopurine 16 or 8‐chloropurine 19, respectively, or by hydrolysis of 6‐N‐methylformamidopurine 12, which was prepared from 6‐dimethylaminopurine 13 by selective oxidation.
Synthesis of 2,2,4‐triphenyl‐3‐propenoyl‐3,4‐dihydro‐2H‐benzopyran via a lithiated allene
Authors: Adegoke E. A. , Emokpae T. A. , Ephraim‐Bassey H.
Published: March 2009

Synthetic routes to 2,2‐disubstituted chromanes and their hetero‐ring‐unsaturated analogues are briefly reviewed. A variety of common alkylating agents has been involved in such routes. Here, however, the alkylating agent is the lithiated form of 4‐tetrahydropyran‐2‐yloxybuta‐1‐2‐diene V. This reacted with benzophenone to give XIV. The synthesis of chromane XIV is here reported for the first time. The route to XIV is also both new and may prove versatile to other hetero‐ring‐substituted chromanes.
Reactions with α‐substituted cinnamonitriles. A novel synthesis of hexa‐substituted pyridines
Authors: Hammouda Hamdy A. , Ahmed  , El‐Reedy M. , Hussain Sohair M.
Published: March 2009

Whereas acetoacetanilide (II) reacted with α‐cyano‐ and α‐benzoylcinnamonitrile derivatives Ia‐e to give hexa‐substituted pyridines III and V, it reacted with α‐carboxamido‐ and α‐thiocarboxamidocinnammonitrile derivatives If‐h to afford penta‐substituted pyridines VI. One mole of acetonedicarboxylic acid dianilide (VII) reacted with two moles of each of α‐cyano‐ and α‐thiocarboxamidocinnamonitriles Ia,b,f,g to yield the dipyridyl ketones VIII and IX, respectively. On the other hand, α‐benzoyl‐ and α‐ethoxycarbonylcinnamonitriles Ic,d,i,j reacted with VII in equimolecular ratio to give the pyran derivaties X and XI, respectively. Several schemes were proposed to illustrate reactions steps. The structures of the synthesized compounds were proved by chemical and spectral methods.
Thermally‐induced radical rearrangement of 2‐(2‐thienylmethoxy)‐and 2‐(2‐benzo[b]thienylmethoxy)tropones
Authors: Takeshita Hitoshi , Mametsuka Hiroaki , Motomura Hideshi
Published: March 2009

Upon heating at ca. 160°, 2‐(2‐thienylmethoxy)tropone afforded 3‐ and 5(2‐thienylmethyl)tropolones. Formation of 3,5‐bis(2‐thienylmethyl)tropolone and unsubstituted tropolone indicated a radical chain mechanism for the thermolysis.
Reaction of 2‐acetyltetralone with some esters of benzoic acid
Authors: Arcoleo A. , Gottuso M. , Giammona G. , Fontana G. , Abbate G.
Published: March 2009

In order to investigate the pharmacological screening of a number of pyran‐4‐ones their synthesis by cyclization with sulphuric acid of the corresponding 1,3,5‐triketones has been carried out with high yields. In the course of preparation of the latter the reaction of 2‐acetyltetralone with some esters of benzoic acid derivatives has been studied and in particular, for a number of them, an interesting nucleophilic substitution of a chlorine atom with an alkoxy group on a benzenic nucleus has been evidenced.
Tautomeric behavior of 3‐(α‐arylhydrazono)methyl‐2‐oxo‐1,2‐dihydroquinoxalines between hydrazone imine and diazenyl enamine forms
Authors: Kurasawa Yoshihisa , Muramatsu Muneto , Yamazaki Kaoru , Tajima Setsuko , Okamoto Yoshihisa , Takada Atsushi
Published: March 2009

3‐(α‐Chlorophenylhydrazono‐1,3,4‐oxadiazol‐2‐ylmethyl)‐2‐oxo‐1,2‐dihydroquinoxalines 4a‐d and 3‐(α‐chlorophenylhydrazono)methoxycarbonylmethyl‐2‐oxo‐1,2‐dihydroquinoxalines 5a‐c have been clarified to exhibit the characteristic tautomeric equilibria between the hydrazone imine form C and the diazenyl enamine form D with a long‐range prototropy by means of the pmr and 13C‐nmr spectroscopies.
Crystal structure determination of 10‐trifluoroacetylphenothiazine
Authors: de Meester Patrice , Chu Shirley S. C.
Published: March 2009

The structure of the title compound has been determined by single crystal X‐ray methods. The crystals are monoclinic, space group P21/n with four molecules in a cell of dimensions a = 14.365(4), b = 5.942 (2), c = 17.359(3) Å, β = 119.88(2)° and V = 1298.0(6) Å. The structure has been refined by full‐matrix least‐squares to R = 0.043 using 1650 observed reflections. This study shows that the folding angle between the two benzo planes is 131.8(1)°, one of the smallest values observed in phenothiazine derivatives. Also, the trifluoroacetyl group is perpendicular to the plane bisecting the tricyclic ring, in contrast to most 10‐aryl‐substituted phenothiazines where the substituent is approximately parallel to the plane bisecting the tricyclic ring.
A convenient synthesis of nitro‐substituted 1,2‐benzisothiazol‐3(2H)‐one 1,1‐dioxides (nitrosaccharins)
Authors: Saari Walfred S. , Schwering John E.
Published: March 2009

Nitro‐substituted 1,2‐benzisothiazol‐3(2H)‐one 1,1‐dioxides (nitrosaccharins) have been synthesized by amminolysis of nitro 2‐chlorosulfonylbenzoate esters. This method appears to have advantages over the original procedure of oxidation of an ortho‐toluenesulfonamide.
Phosphoryl chloride induced ring contraction of 1,4‐benzodiazepinones to chloromethylquinazolines
Authors: Combs Donald W. , Press Jeffery B. , Mulvey Dennis , Gray‐Nunez Yolanda , Bell Stanley C.
Published: March 2009

A ring contraction of 1,4‐benzodiazepin‐2‐one to 2‐chloromethylquinazoline in phosphoryl chloride is described. The intermediacy of an aziridinoquinazoline is proposed.
The reaction products of 2H‐isoindole‐4,7‐dione derivatives with 2‐aminobenzenethiol
Authors: Nan'Ya Seiko , Tange Toshiaki , Maekawa Eturǒ , Ueno Yoshio
Published: March 2009

From 2,3,4‐Trisubstituted oxazolium‐5‐oxides and 2‐methyl‐, 2‐phenyl‐ or 2‐bromo‐1,4‐benzoquinone 1,2,3,5‐tetrasubstituted 2H‐isoindole‐4,7‐dione derivatives were prepared. These compounds were condensed with 2‐aminobenzenethiol to produce 1,2,3‐trisubstituted or 1,2,3,5‐tetrasubstituted 4H‐pyrrolo[3,4‐a]phenothiazin‐4‐one derivatives. In the case of 1,2,3‐trisubstituted 5‐methyl‐2H‐isoindole‐4,7‐dione 1,2,3,5‐tetrasubstituted 7‐(2‐mercaptophenyl)imino‐2H‐isoindole‐4‐one was obtained instead of the expected phenothiazinones.
Synthèse d'éthers diéthylamino éthyliques de bibenzofurannes et de bis‐benzofuryl cétones, comme analogues pharmacochimiques de la Tilorone
Authors: Guillaumel Jean , Royer René
Published: March 2009

Les éthers diéthylaminoéthyliques de divers bis‐(Bz‐hydroxy) bibenzofurannes sont préparés, soit à partir d'alcool hydroxy‐2‐méthoxy‐5 benzylique, soit à partir d'acides benzofuranne carboxyliques. Les éthers correspondents de bis‐(Bz‐hydroxy benzofuryl‐2) méthanones le sont à partir d'aldéhydes méthoxy salicyliques.
Obtention d'alkoxy‐2 cyano‐3 2H chromènes
Authors: Auzou Gilles , René Loïc
Published: March 2009

Les alkoxy‐2 cyano‐3 2H chromènes sont obtenus par alcoolyse des morpholino‐2 cyano‐3 2H chromènes correspondants.
Isomers and aza‐analogues of indoxyl containing nitrogen at a ring‐fusion position: Coupling reactions with electrophiles and attempted oxidations
Authors: Katritzky Alan R. , Caster Kenneth C. , Rubio Olga , Schwarz Otto
Published: March 2009

Derivatives of four series of compounds derived from isomers of indoxyl with the nitrogen at the bridgehead and two further series of aza‐analogues are prepared and their absorption properties studied.
The synthesis of 3‐hydroxymethyldibenzo[b,f]thiepin 5,5‐dioxide, a prostaglandin antagonist
Authors: Hands David , Marley Hugh , Skittrall Stephen J. , Wright Stanley H. B. , Verhoeven Thomas R.
Published: March 2009

An economic synthesis of 3‐hydroxymethyldibenzo[b,f]thiepin 5,5‐dioxide, a novel prostaglandin antagonist, is described. The key step in the synthesis is the formation of a carboxyphenylacetic acid by carboxylation of a toluic acid dianion, followed by cyclisation to the tricyclic ketone. Readily available starting materials are used in the synthesis and conditions have been found at each stage to give pure intermediates, requiring little purification, in high yield.
The preparation of selected benzopyrano[3,4‐b]pyrazoles by the condensation of c(α), n‐dilithiocarboalkoxyhydrazones and salicylate esters
Authors: Huff Ann M. , Beam Charles F.
Published: March 2009

Selected C(α),N‐dilithiocarboalkoxyhydrazones were prepared in an excess of lithium diisopropylamide (LDA) and condensed with a variety of salicylate esters to give intermediates that were acid‐cyclized to benzopyrano[3,4‐b]pyrazoles (coumarin‐pyrazoles).
A novel synthesis of benzofuran and related compounds. I. The vilsmeier reaction of phenoxyacetonitriles
Authors: Hirota Takashi , Fujita Hiroko , Sasaki Kenji , Namba Tetsuto , Hayakawa And Shohei
Published: March 2009

A novel synthesis of 2‐benzofurancarboxylic acid derivatives by the Vilsmeier reaction of phenoxyacetonitriles is described.
Pesticidal Mannich Bases Derived from Isatinimines
Authors: Ram Vishnu J. , Mishra L. , Pandey H. N. , Vlietinck A. J.
Published: March 2009

Mannich bases from isatinimines and isatin hydrazones are synthesized for evaluation of their pesticidal activities. Among all the prepared Mannich bases only N‐dimethylaminomethyl‐3‐(p‐bromophenyl)iminoindol‐2‐one exhibited herbicidal activity in pre‐ and post‐emergent tests.
A convenient synthesis and antifungal activity of 1‐aryl‐1H‐ and 1‐aryl‐3‐heteroaryl‐1H‐pyrazolo[3,4‐b]quinoxalinesA Convenient Synthesis and Antifungal Activity
Authors: Kurasawa Yoshihisa , Muramatsu Muneto , Yamazaki Kaoru , Tajima Setsuko , Okamoto Yoshihisa , Takada Atsushi
Published: March 2009

Novel 1‐aryl‐1H‐ and 1‐aryl‐3‐heteroaryl‐1H‐pyrazolo[3,4‐b]quinoxalines (flavazoles)9a‐c, 12, 13were synthesized from 3‐methyl‐2‐oxo‐1,2‐dihydroquinoxaline 5 and the 3‐triazolylmethylene‐2‐oxo‐1,2,3,4‐tetrahydroquinoxaline 6, respectively,viaa facile hydrazone synthesis using aryl diazonium salts. Some of the above flavazoles and their related compounds exhibited the antifungal activity in some extent. The above results are described.
A facile synthesis of 1‐aryl‐3‐heteroaryl‐1H‐pyrazolo[3,4‐b]quinoxalines and related compounds with antifungal activitySynthesis of 1‐Aryl‐3‐heteroaryl‐1H‐pyrazolo[3,4‐b]quinoxalines
Authors: Kurasawa Yoshihisa , Muramatsu Muneto , Yamazaki Kaoru , Tajima Setsuko , Okamoto Yoshihisa , Takada Atsushi
Published: March 2009

The novel 1H‐pyrazolo[3,4‐b]quinoxalines (flavazoles) 9–15 were synthesized from 3‐methoxycarbonylmethylene‐2‐oxo‐1,2,3,4‐tetrahydroquinoxaline 6 via a convenient hydrazone synthesis, and these flavazoles were clarified to have the antifungal activity.
Pyridoannelation of hindered ketones via their nitrogen derivatives. Synthesis of 5,6,7,8‐tetrahydro‐8,9,9‐trimethyl‐5,8‐methanoquinolines from (+)‐camphor
Authors: Chelucci Giorgio , Delogu Giovanna , Gladiali Serafino , Soccolini Francesco
Published: March 2009

The transformation of (+)‐camphor into (+)‐8,9,9‐trimethyl‐ and (+)‐2,8,9,9‐tetramethyl‐5,6,7,8‐tetrahydroquinolines 1 and 2 has been accomplished by three different procedures based on the elaboration of imino or enamino intermediates. The values of the rotatory powers for both the compounds are reported.
Synthesis of novel pyrimidine nucleoside analogues
Authors: De Napoli Lorenzo , Mayol Luciano , Piccialli Gennaro , Rossi Mosé , Santacroce Ciro
Published: March 2009

Two new tetrazolopyrimidinedeoxynucleosides were synthesized and their physico‐chemical data are described. Results of preliminary analyses of their biological properties are also reported.
Synthesis of some 7‐substituted‐2,4,8(1H,3H,7H)pyrimido[5,4‐d]pyrimidinetriones
Authors: Pendergast William , Hall William R.
Published: March 2009

A synthesis of 2,4,8‐pyrimido[5,4‐d]pyrimidinetriones under mild conditions from ethyl 5‐ethoxymethyleneamino‐orotate allows the introduction of a variety of substituents regiospecifically into the 7‐position. The 7‐methyl and 7‐benzyl derivatives were methylated with trimethyl phosphate to the 1,3,7‐trialkyl derivatives.
Synthesis of some 5‐Aryl‐4,5‐dihydro[1]benzoxepin‐3(2H)‐ones and 5‐aryl‐5,6,8,9‐tetrahydro‐7H‐benzocyclohepten‐7‐ones from benzoxepinoisoxazolone and benzocycloheptaisoxazolone derivatives
Authors: Deshayes Christian , Pujol Bernard , Gelin Suzanne
Published: March 2009

Some 5‐aryl‐4,5‐dihydro[1]benzoxepin‐3(2H)‐ones and 5‐aryl‐5,6,8,9‐tetrahydro‐7H‐benzocyclohepten‐7‐ones were synthesized by hydrogenolytic cleavage of the isoxazole ring of 4‐aryl‐3‐oxo‐3,3a,4,10‐tetrahydro[1]‐benzoxepino[3,4‐c]isoxazoles or 4‐aryl‐3‐oxo‐3a,4,9,10‐tetrahydro‐3H‐benzo[4,5]cyclohepta[1,2‐c]isoxazoles which in turn were prepared from ethyl 3‐oxo‐4‐phenoxybutanoate or ethyl 3‐oxo‐5‐phenylpentanoate by simple methods.
Syntheses and conformations of some cyclic hydroxamates. X‐Ray crystal structure of 2‐(p‐nitrobenzoyl)tetrahydro‐2H‐1,2‐oxazine
Authors: Johnson James Elver , Hodzi Richard , Todd Susan L. , De Meester Patrice , Chu Shirley S. C.
Published: March 2009

Alkylation of potassium p‐nitrobenzohydroxamate with 1,4‐dibromobutane gave 2‐(p‐nitrobenzoyl)tetrahydro‐2H‐1,2‐oxazine (3). The X‐ray crystal structure of 3 has been determined. The crystals are monoclinic, space group P21/n with a = 6.749(1), b = 7.644(1), c = 21.557(2)Å, β = 98.89(1), V = 1098.8(2)Å3 and Z = 4. The structure, which was refined to R = 0.039 using 1340 observed reflections, shows the oxazine and carbonyl oxygen atoms trans to each other. Alkylation of potassium benzohydroxamate with 1,3‐dibromobutane gave a mixture of 3‐methyl‐2‐benzoyloxazolidine (4) and 5‐methyl‐2‐benzoyloxazolidine (5). The 1H and 13C nmr spectra of the mixture of 4 and 5 indicates that these cyclic hydroxamates exist predominantly in the s‐trans conformation.
Electrophilic hydrogen‐deuterium exchange of some deactivated pyrroles
Authors: Gilow Helmuth M. , Hong Yoon H. , Millirons Paula L. , Snyder Richard C. , Casteel William J.
Published: March 2009

The rate coefficients and partial rate factors for the hydrogen‐deuterium exchange of some 1‐substituted pyrroles (1‐substituents = ‐COCH3, ‐ COC6H5, ‐SO2CH3, ‐SO2CF3, ‐N(CH3)3, ‐NH(CH3)2, ‐SO2C6H5) in deuterated trifluoroacetic acid have been determined. In all cases the rate of exchange is faster at the 2‐position. Similarly, the hydrogen‐deuterium exchange of some pyrroles with electron withdrawing substituents in the 2‐position indicate a relative reactivity of 4→ 5→ 3‐position with the selectivity being greatest for the more electron withdrawing groups. A nitro group in the 3‐position of pyrrole shows a relative reactivity of 5→2→4‐position for the hydrogen‐deuterium exchange in deuterated trifluoroacetic acid. A linear correlation is observed for the log of the rate coefficient of the hydrogen‐deuterium exchange at the 4‐position of some 2‐substituted pyrroles and the difference in the calculated energy of formation of the pyrrole and the corresponding 4‐deuterated cation.
Cross‐coupling reaction of chloropyrazines with ethylenes
Authors: Akita Yasuo , Noguchi Tomofumi , Sugimoto Michinobu , Ohta Akihiro
Published: March 2009

Various chloropyrazines and their N‐oxides were submitted to the cross‐coupling reaction with ethylenes, such as styrene, ethyl acrylate and acrylonitrile. While the chloro‐phenylpyrazines and 2‐chloropyrazine 1‐oxides were slugglish in this reaction system, the expected products were obtained from almost all the 2‐chloro‐3,6‐dialkylpyrazines and their 4‐oxides in moderate to good yields.