bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amination of 4‐nitropyridazine 1‐oxides by liquid ammonia/potassium permanganate
Authors: Tondys Hanna , Plas Henk C. Van Der 
Published: March 2009

AbstractTreatment 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

AbstractThe 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

Abstract3‐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

AbstractAn 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

AbstractThe 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

AbstractThe 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

AbstractPlusieurs 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

AbstractOn 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

AbstractReaction 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

AbstractThe 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

AbstractA 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

AbstractL'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

Abstract4‐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

AbstractMethods 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

AbstractA 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

AbstractAryl 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

AbstractThe 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

AbstractThe 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

AbstractPyruvaldehyde 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

AbstractThe 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

AbstractSubstituted 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

AbstractUne 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

AbstractCondensation 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

AbstractRemarkable 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

Abstract2,3‐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

AbstractThe 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

AbstractStarting 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

AbstractThe 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

AbstractSynthesis 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

AbstractSynthetic 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

AbstractWhereas 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

AbstractUpon 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

AbstractIn 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

Abstract3‐(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

AbstractThe 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

AbstractNitro‐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

AbstractA 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

AbstractFrom 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.