bluuebunny/crossref_metadata_2025 huggingface dataset:
Polycyclic azines. III. Synthesis of 3‐aminoimidazo[1,5‐a]pyridine derivatives by cyclodesulfurization of N′‐Substituted‐N‐(2‐pyridylmethyl)thioureas with dicyclohexylcarbodiimide
Authors: Bourdais J. , Omar A.‐Mohsen M. E.
Published: March 2009

A series of 3‐substituted aminoimidazo[1,5‐a]pyridine derivatives have been synthesized by cyclodesulfurization of a variety of N′‐substituted‐N‐(2‐pyridylmethyl)thioureas with dicyclohexylcarbodiimide (DCCD). 1H Nmr spectral analysis of all synthesized compounds is given.
Synthesis of 4,7‐dimethoxyindoles bearing substituents at the c‐5 and c‐6 positions and studies on their demethylation products
Authors: Malesani Giorgio , Galiano Fabio , Ferlin Maria Grazia , Masiero Sergio
Published: March 2009

Syntheses of some 4,7‐dimethoxyindoles bearing methyl, amino or acetamido groups at the C‐5 and C‐6 positions were investigated. The presence of these substituents made possible the isolation of the corresponding 4,7‐dihydroxyindole derivatives obtained by long reflux with aluminium chloride in benzene solution.
An infrared study on N‐methyloxazolidine‐2‐thione and ‐2‐selenone
Authors: Devillanova Francesco A. , Verani Gaetano
Published: March 2009

An infrared investigation on N‐methyloxazolidine‐2‐thione and ‐2‐selenone in the range 4000–200 cm−1 is reported. The direct comparison of the ir spectra for these compounds allowed us to identify the vibrations related to CS and CSe, and support the previous assignments of the CS modes in the oxazolidine‐2‐thione; for this compound it has not been possible to synthesize its selenium isologue. On the whole, these experimental assignments are in agreement with those reported for oxazolidine‐2‐thione. The CS and CSe modes, contributing to the bands falling below 600 cm−1, are compared with those of several similar pentaatomic rings.
Novel synthesis of the pharmacologically important 1‐substituted‐6‐phenyl‐4H‐s‐triazolo[4,3‐a][1,4]benzodiazepines
Authors: Hester Jackson B.
Published: March 2009

Several 6‐phenyl‐4H‐s‐triazolo[4,3‐a][1,4]benzodiazepines have useful biological activity both in experimental animals and in man. This manuscript describes a novel synthesis of these compounds from intermediates that do not have a pre‐formed benzodiazepine ring system.
The behaviour of 3‐methyl‐5‐(o‐r‐styryl)‐4‐nitroisoxazoles under electron impact. I
Authors: Martíanez R. , Cortéas E.
Published: March 2009

The mass spectra of several 3‐methyl‐5‐(o‐R‐styryl)‐4‐nitroisoxazoles have been studied. The fragmentation patterns and mechanisms postulated have been confirmed by the determination of the metastable peaks.
The structure of some methyl and benzyl malonate derivatives of pyrimidine
Authors: Reynolds G. Fredric , Fenwick Marc B.
Published: March 2009

Reaction of 2,4,6‐trichloropyrimidine with sodium dibenzylmalonate in p‐dioxane gave 4,6‐dichloro‐2‐(dibenzylmalonyl)pyrimidine, while reaction of 2,4,6‐trichloropyrimidine with sodium dimethylmalonate yielded both 4,6‐dichloro‐2‐(dimethylmalonyl)pyrimidine and 2,2‐bis‐(4,6‐dichloropyrimidin‐2‐yl)dimethylmalonate. Structural studies using nmr, ir and uv spectroscopy indicate that for the former two compounds in basic solvent, an equilibrium exists between the keto forms and resonance‐stabilized enolate ions.
1H Nmr stuctural analysis of N3′‐dialkylaminoethyl derivatives from azabicyclospirohydantoins
Authors: Trigo G. G. , Espada M. , Gáalvez E.
Published: March 2009

Based on the data from 1H nmr spectra, the structure and spatial conformation of the N3′‐β‐dimethyl and diethylaminoethyl derivatives from 3‐alkyl‐3‐azabicyclo[3.2.1]octane‐8‐spiro‐5′‐hydantoins and 3‐alkyl‐3‐azabicyclo[3.3.1]nonane‐9‐spiro‐5′‐hydantoins are established. The monosubstitution on the imide nitrogen atom has also been confirmed.
The reaction of alkylpyrazine anions with some electrophiles. Synthesis of 1,2‐bis(2‐pyrazyl)ethanes
Authors: Houminer Yoram , Sanders Edward B.
Published: March 2009

The reaction of alkylpyrazine anions with iodine, 1,2‐dibromoethylene or oxygen gives 1,2‐bis‐(2‐pyrazyl)ethanes.
Proton spin‐lattice relaxation studies. N‐aryl‐1‐isoindolinones
Authors: Khadim Mohammad A. , Colebrook Lawrence D. , Hall Laurance D.
Published: March 2009

Proton spin‐lattice relaxation rates (R1 values) have been measured, at 270 MHz, for a series of N‐aryl isoindolinones. A normalization procedure has been used to enable comparison of R1 values in different compounds by minimizing the effects on relaxation rates of changes in motional correlation times accompanying changes in substitution patterns. A substantial (4.3‐fold) dynamic range of R1 values has been observed, and individual values have been correlated with the molecular environments of the nuclei. There is evidence for an interring relaxation process.
Some fused‐ring succinimides as potential anticonvulsants
Authors: Campaigne E. , Yodice Richard
Published: March 2009

The syntheses of two compounds, which are fused‐ring succinimides, prepared as potential anticon‐vulsants, are described. The compounds are 3,4,5,6‐tetrahydro‐7‐methyl‐6‐oxoindeno[7,1‐bc]thiepin‐4a,5‐(2H)dicarboximide and 6,7,8,9‐tetrahydro‐2‐oxo‐1H‐benz[cd]azulene‐1,9a‐(2H)dicarboximide. The spirodioxolane of the latter compound was also prepared by ketalization.
Synthesis and photocyclization of some 4‐(5)arylethenylimidazoles
Authors: Lindgren Gerd , Stensiö Karl‐Erland , Wahlberg Kerstin
Published: March 2009

The synthesis of eleven 4‐(5)arylethenylimidazoles and their separation into cis and trans isomers is described. Ir, uv, nmr, and mass spectrometric data of the compounds are given. The photocyclization of the unsubstituted and p‐substituted compounds is reported.
Photoelectron spectroscopy of heterocycles. Azaindenes and azaindolizines
Authors: Kovać B. , Klasinc L. , Stanovnik B. , Tišler M.
Published: March 2009

The HeI photoelectron (PE) spectra of indole (1), benzimidazole (2), indazole (3), 3‐chloro‐indazole (4), imidazo[1,2‐b]pyridazine (5), 6‐chloroimidazo[1,2‐b]pyridazine (6), 2‐phenyl‐imidazo[1,2‐b]pyridazine (7), 2‐phenyl‐6‐chloroimidazo[1,2‐b]pyridazine (8), tetrazolo[1,2‐a]‐pyridine (9) and 8‐cyanotetrazolo[1,5‐a]pyridine (10) have been recorded. The spectra of 2–10 are of special interest for studying lone pair interactions. The assignment of the PE spectra submitted here, conjointly with the electronic structure of the studied compounds is discussed on the basis of molecular orbital calculations.
Photochemical synthesis of heteroatom‐containing polycyclic aromatic compounds
Authors: Maruyama Kazuhiro , Otsuki Tetsuo , Mitsui Kiichiro , Tojo Masahiro
Published: March 2009

Anthra[2,1‐b]furan, anthra[2,1‐b]benzo[d]furan, anthra[2,1‐b]thiophene, anthra[1,2‐b]thiophene, anthra[2,1‐b]benzo[d]thiophene, anthra[2,1‐b]pyrrole and naphtho[2,3‐c]carbazole derivatives were synthesized in fairly good yields by a one‐pot photocycloaddition reaction of 2,3‐disubstituted 1,4‐naphthoquinone with 1,1‐diarylethylene. This is the first reported synthesis of these aromatic compounds.
New macrocyclic polyethers with remote binding sites
Authors: Rebek J. , Wattley R. V.
Published: March 2009

The synthesis and binding properties of new macrocyclic polyethers are described. These systems incorporate 2,2′‐bipyridyl functions in such a fashion that binding of metal nuclei can occur at either the macro‐cycle or the bipyridyl function. Evidence is presented that binding of alkali metals occurs at the crown ether cavity while binding of transition metals occurs at the bipyridyl function. Simultaneous binding of two different metals is interpreted in terms of electronic and allosteric effects.
Analogs of heterocyclic CNS agents
Authors: Moffett Robert Bruce
Published: March 2009

Thirty‐five oxazoles, thiazoles, piperazines and related compounds, analogs of known CNS agents, were prepared and tested. None were more active than the lead compounds.
Selenium‐containing pancreatic imaging agents. Synthesis of β‐2‐ and β‐3‐selenienylalanine
Authors: Frejd T. , Gronowitz S. , Davis M. A. , Sadeh T.
Published: March 2009

Selenophene‐alanines, labelled with γ‐emitting selenium‐75, are potential diagnostic agents for disorders of the pancreas. Two of the positional isomers of selenienyl‐alanine were synthesized, namely 2‐selenienylalanine [2‐amino‐3‐(2‐selenienyl)propanoic acid] (88% yield) and 3‐selenienylalanine [2‐amino‐3‐(3‐selenienyl)propanoic acid] (65% yield). Both amino acids were prepared from the known chloromethyl selenophenes (2‐ and 3‐) by reaction with diethyl acetamidomalonate and subsequent hydrolysis. The method employed was found to be more productive than others which were tried.
Oxidation of 3,4‐disubstituted isoxazolin‐5‐ones
Authors: Beccalli Egle M. , Marchesini Alessandro , Gioia B.
Published: March 2009

The oxidation of 3,4‐disubstituted isoxazolin‐5‐ones with active manganese dioxide leads to the formation of C‐C and/or C‐N linked coupling products.
Heteroatomic chains and their products of cyclisation. IV. t‐butyl‐2‐phthalimido‐2‐(3,6‐dihydro‐1,3‐2H‐thiazine‐2‐yliden)‐acetates substituted in position 5 by a functional group
Authors: Duguay Guy , Guémas Jean‐Pierre , Meslin Jean‐Claude , Pradère Jean‐Paul , Reliquet Françoise , Reliquet Alain , Tea‐Gokou Célestin , Quiniou Hervé , Rabiller Claude
Published: March 2009

Substituted N′‐thioacetylformamidines, readily enthiolized, exist in fact in the form of zwitterions 8 with the transfer of the mobile hydrogen on the nitrogen N′. These zwitterions under (4 + 2) cyclocondensation with dienophiles. The dihydrothiazines formed (10) are possible interesting intermediates in the synthesis of cephems and cephalosporin analogs.
The insertion and extrusion of heterosulfur bridges. XI. Desulfurizations of condensed thiophenes by means of methanol and a molybdena catalyst
Authors: Klemm L. H. , Karchesy Joseph J. , Lawrence Ross F. , Wang Pih
Published: March 2009

Desulfurizations of 2‐methyl‐ (1b), 4‐methyl‐ (1c), and 4,6‐dimethyldibenzothiophenes (1d), benzo[b]thiophene (2), and benzo[b]naphtho[2,1‐d]thiophene (5) were effected by means of methanol and a sulfided CMA catalyst [a mixed oxide of Co(II), Mo(VI), and Al(III)] at 450°. Desulfurization was accompanied by processes of demethylation and ring hydrogenation in the case of 1d and by both methylation and demethylation in the cases of 1b and 1c. Compound 2 gave ethylbenzene (80%), while 5 produced 2‐phenylnaphthalene (69%).
Chemical behaviour of 1,4‐benzoxazine
Authors: Chioccara Francesco , Prota Giuseppe , Novellino Ettore
Published: March 2009

The attempted synthesis of 2H‐1,4‐benzoxazine, which is unreported in the literature, gives a mixture of polymeric aldolization products. The major product, isolated in crystalline form, is formulated as the cyclic trimer 5.
Studies on reactive intermediates. Part I. An approach to the synthesis of 2‐phenyl‐7‐carbethoxy‐5H‐1,3,4‐thiadiazolo[2,3‐a]pyrimidin‐5‐one
Authors: Daneshtalab M. , Motamedi K.
Published: March 2009

2‐Phenyltetrazolo[4,5‐a]‐1,3,4‐thiadiazole (4), in its azido form, reacted with diethyl fumarate and diethyl maleate to give 2‐phenyl‐7‐carbethoxy‐5H‐1,3,4‐thiadiazolo[2,3‐a]pyrimidin‐5‐one (5). To assign the structure of compound 5, 2‐phenyl‐5‐carbethoxy‐7H‐1,3,4‐thiadiazolo[2,3‐a]pyrimidin‐7‐one (6) was prepared from the reaction of 2‐amino‐5‐phenyl‐1,3,4‐thiadiazole (7) with diethylacetylene dicarboxylate. Physical properties and spectral data of compound 6 were different from compound 5. Theoretical and experimental aspects are discussed.
An improved synthesis of 3,5‐disubstituted isoxazoles and pyrazoles from C(α),O‐dilithiooximes and C(α),N‐dilithiophenylhydrazones
Authors: Fulmer Tammy D. , Dasher Lisette P. , Bobb Bonni L. , Wilson Jana D. , Sides Kimberly L. , Beam Charles F.
Published: March 2009

C(α),O‐Dilithiooximes and C(α),N‐dilithiophenylhydrazones were prepared using an excess of lithium diisopropylamide (1:3). Condensation with esters followed by acid cyclization gave isoxazoles and pyrazoles.
Discrimination of the geometrical isomers of 2,3‐, 2,5‐, and 2,6‐dimethylpiperazines based on 1 HNmr spectral data
Authors: Tsutsui Mayumi , Watanabe Tokuhiro , Ohta Akihiro , Takizawa Kayoko
Published: March 2009

1 H‐Nmr spectra of cis and trans isomers of 2,3‐, 2,5‐, and 2,6‐dimethylpiperazines were taken at various temperatures. The spectra of geometrical isomers bearing the ae or ea dimethyl groups showed broadening at lower temperatures. It was clarified that the measurement of the spectra at lower temperatures is useful for the discrimination of the geometrical isomers of dimethylpiperazines.
The photolysis of the l‐cycloalkoxy‐5‐chloro‐1,2,3‐benzotriazole system
Authors: Feld W. A. , Servé M. P.
Published: March 2009

Three l‐cycloalkoxy‐5‐chloro‐1,2,3‐benzotriazoles were photolyzed at 254 nm. The major photolytic pathway yielded the corresponding cyclic ketone and 4,4′‐dichloroazobenzene.
Mononuclear heterocyclic rearrangements 5. Kinetic Investigation of the behaviour of (e)‐ and (z)‐phenylhydrazones of 3‐benzoyl‐5‐phenyl‐1,2,4‐oxadiazole in benzene. Isomerization and rearrangement
Authors: Frenna Vincenzo , Vivona NicolÓ , Spinelli Domenico , Consiglio Giovanni
Published: March 2009

The kinetic behaviour of the geometrical isomers I‐E and I‐Z of the title compound in the presence of piperidine in benzene has been investigated. The kinetic results suggest that I‐Z rearranges directly into 2,5‐diphenyl‐4‐benzoylamino‐1,2,3‐triazole (II), whereas I‐E probably rearranges only through the intermediate I‐Z formed by isomerization. All the reactions studied are piperidine‐catalyzed.
Synthesis of 2‐amino‐3‐hydroxy‐ and of 2,3‐diamino‐3H‐1,4‐benzodiazepines
Authors: Gatta Franco , Del Giudice Maria Rosaria , Di Simone Luciano , Settimj Guido
Published: March 2009

A new synthesis of 7‐chloro‐2,3‐diamino‐5‐phenyl‐3H‐1,4‐benzodiazepines is described, which allows for the preparation of compounds bearing the same or different substituents at the 2 and 3 positions, starting from 2‐amino‐7‐chloro‐3‐hydroxy‐5‐phenyl‐3H‐1,4‐benzodiazepines.
5‐Amino‐4,5‐dihydroisoxazoles. Part I. 5‐Amino‐3‐aryl‐4‐methylene‐4,5‐dihydroisoxazoles and 4‐aminomethyl‐3‐arylisoxazoles from 5‐amino‐4‐aminomethyl‐3‐aryl‐4,5‐dihydroisoxazoles
Authors: Pocar Donato , Rossi Luisa Maria , Trimarco Pasqualina , Vago Luciano
Published: March 2009

5‐Amino‐4‐aminomethyl‐3‐aryl‐4,5‐dihydroisoxazoles 2 were obtained by cycloaddition of nitrile oxides to 1,3‐diaminopropenes 1. On reaction with methyl iodide the corresponding 4‐(quaternary)‐ammoniomethyl iodides 3 were formed. These compounds, on reaction with bases, afforded 5‐amino‐3‐aryl‐4‐methylene‐4,5‐dihydroisoxazoles 4. The acid‐catalyzed deamination of compounds 2 afforded 4‐aminomethyl‐3‐arylisoxa‐zoles 5 and 3‐arylisoxazoles as retro‐Mannich products. The deamination of 2 to yield 5 was also obtained by base catalysis.
Single crystal X‐ray diffraction analysis of 2,3a,4,5‐tetrahydro‐7,8‐dimethoxy‐3a‐methyl‐3H‐benz[g]indazol‐3‐one hemihydrate
Authors: Rahman A. , Ealick S. E. , Van Der Helm Dick , Berlin K. Darrell , Hashem M. M.
Published: March 2009

The structure of 2,3a,4,5‐tetrahydro‐7,8‐dimethoxy‐3a‐methyl‐3H‐benz[g]indazol‐3‐one hemihydrate was unequivocally established by means of an X‐ray diffraction analysis of a single crystal. The molecule crystallizes in the space group C2/c with unit cell parameters of a = 18.839(4), b = 7.7694(7), c = 18.211(2) Å and β = 101.06(1). The structure was solved by direct methods and refined by least‐squares methods to an R‐value of 0.069 for 2689 reflections. The indazol‐3‐one unit of the molecule is non‐planar.
β‐Dicéto énamines hététrocycliques: 1. Indanediones‐1,3 substituées en 2 par un hétérocycle azoté
Authors: Ploquin J. , Sparfel L. , Le Baut G. , Floc'h R. , Letourneux Et Y.
Published: March 2009

La réaction de condensation de divers hétérocycles azotés mono‐ ou pluriméthytes sur les anhydrides phtaliques conduit à des aryl‐2 indanediones‐1,3. Les auteurs étudient la formation intermédiaire de picoly‐lidényl‐phtalides dans la série des méthyl‐pyridines et précisent l'influence du solvant et de la température sur la vitesse de formation des (pyridyl‐2 et‐4)‐2 indanediones‐1,3. L'examen des spectres ir et de rmn permet de confirmer que ces indanediones existent sous une forme β‐dicéto‐énamine en résonance avec une forme bétaînique.
4‐bromo‐5‐methyl‐(2H)‐1,2,6‐thiadiazin‐3(6H)one 1,1‐dioxides
Authors: Pilgram Kurt , Skiles Richard D.
Published: March 2009

The title compounds, bearing an alkyl and/or bromine substituent on nitrogen, were synthesized. Unlike 5‐bromo‐6‐methyluracil, 4‐bromo‐5‐methyl‐(2H)‐1,2,6‐thiadiazin‐3‐(6H)one 1,1‐dioxides have the ability to act as a bromonium ion source.
Chemistry of the phenoxathiins and isosterically related heterocycles. XI . The synthesis and 13C‐NMR spectroscopy of 2‐azaphenoxathiin
Authors: Caldwell Steven R. , Martin Gary E.
Published: March 2009

The synthesis of the 2‐azaphenoxathiin ring system via the intermediary 2‐azaphenoxathiin 2‐oxide is described. Complete assignment of the 13C‐nmr spectrum is reported, based on the observed heteronuclear 1H‐13C spin‐couplings of the system and calculated chemical shifts as assignment criteria. The possible relation of the chemical shift of Cα to the dehidral angle of the system is also discussed.
Quelques réactions nuclé ophiles et électrophiles de la thiéno[2,3‐b]pyrazine. Comparaison de sa réactivite avec celles de thiéno diazines et de la thiényl‐2 pyrazine dans le cas de la nitration
Authors: Bourguignon Jean , Lemarchand Marc , Quéguiner Guy
Published: March 2009

Nous avons étudié dans cet article l'action du n‐butyllithium, du chlore et de l'acide nitrique en milieu acide sulfurique sur la thiéno[2,3‐b]pyrazine. Cette réaction nous à conduit a comparer dans les mêmes conditions le comportement de la thiéno[2,3‐b] pyrazine à celui des composés suivants: thiéno[2,3‐d]pyridazine, thiéno[2,3‐d]pyrimidine et thiényl‐2 pyrazine.
Synthesis of 3‐[p‐(1′‐pyrazolyl)]phenylsydnones
Authors: Havanur Shambhuling B. , Badami Bharati V. , Puranik Gurubasav S.
Published: March 2009

The synthesis of some hitherto unknown sydnones, i.e., derivatives of 3‐phenylsydnone with a pyrazolyl moiety in the p‐position of the phenyl nucleus, has been described. The structures for all of the sydnones have been confirmed by elemental analysis, and ir and nmr spectral studies.
An Isolation and liquid phase EPR spectra of the cation radical salts of N‐methyl and N‐ethylphenothiazinium perchlorate
Authors: Fujita Hideo , Yamauchi Jun
Published: March 2009

N‐Methyl and N‐ethylphenothiazines were oxidized with bromine and sodium perchlorate to give stable cation radical salts. Their well‐resolved epr spectra were obtained in nitromethane solution. In order to assign the hfs constants, the cation radicals of N‐deuteriomethyl and N‐deuterioethylphenothiazines were prepared with lead tetraacetate and trifluoroacetic acid in solutions.
Stereochemical assignments of the 7‐phenyl‐2‐oxabicyclo[4.1.0]heptanes
Authors: Woodyard James D. , Morris Paul R. , Hobbs Gregory D.
Published: March 2009

A rapid method for making stereochemical assignments based on variant temperature nmr data for the 7‐phenyl‐2‐oxabicyclo[4.1.0]heptanes is described.
Reinvestigation of the reaction of ethyl 4,4,4‐trifluoroacetoacetate with aldehydes and ammonia
Authors: Singh Baldev , Lesher George Y.
Published: March 2009

Reaction of ethyl 4,4,4‐trifluoroacetoacetate with aromatic aldehydes and ammonia gives diethyl 4‐aryl‐2,6‐dihydroxy‐2,6‐bis(trifluoromethyl)‐3,5‐piperidinedicarboxylates (4) instead of diethyl 4‐aryl‐1,4‐dihydro‐2,6‐bis(trifluoromethyl)‐3,5‐pyridinedicarboxylates (3) as reported previously (1).
The 1‐alkoxy‐4,5‐dichloro‐1,2,3‐benzotriazole system
Authors: Feld W. A. , Seybold P. G. , Servé M. P.
Published: March 2009

The 1‐alkoxy‐4,5‐dichloro‐1,2,3‐benzotriazole system has been synthesized and characterized via its physical and chemical properties. INDO/S MO calculations provide a good account of the ultraviolet absorption spectrum.
Preparation of a DSCG‐like bisbenzofuran
Authors: Sunder Shyam , Peet Norton P.
Published: March 2009

The preparation of 6,6′‐[(2‐hydroxy‐1,3‐propanediyl)]bis(oxy)]bis(3‐hydroxy)]‐2‐benzofurancarboxylic acid) diethyl ester trisodium salt trihydrate (6), a compound structurally related to disodium cromoglycate (DSCG), is described.
Identification of 4,5‐unsymmetrically substituted l‐amino‐ and 1‐(N‐arylacetylamino)‐1,2,3‐triazoles by 13C‐NMR
Authors: Tsoleridis C. , Stephanidou‐Stephanitou J. , Alexandrou N. E.
Published: March 2009

13C nmr chemical shifts are used for the structural assignment of isomeric 1‐amino‐1,2,3‐triazoles and 1‐(N‐arylacetylamino)‐1,2,3‐triazoles unsymmetrically substituted with phenyl, methyl or hydrogen in the 4,5‐positions of the triazole ring. A signal at 11 ± 0.6 ppm indicates a 4‐methyl triazole derivative, whereas a signal at 7.9 ± 1 ppm indicates a 5‐methyl triazole. A signal at 120 ± 0.5 ppm (C‐5) indicates a hydrogen in the 5‐position (unsubstituted triazole).
N‐Substituted 4,5‐dihydro‐1,2‐benzothiazepin‐3‐one 1,1‐dioxide
Authors: Camoutsis Ch. , Catsoulacos P.
Published: March 2009

The reaction of 2‐carboethoxyethyl‐4,5‐dimethoxybenzene sulfochloride with substituted pyridines leads to the corresponding sulfonamides. The latter were hydrolysed to the acids, on which a general method for preparing a new ring system was based.
Synthesis and stereochemistry of trans‐ and cis‐2,3‐difluoro‐2,3‐dihydrobenzofuran
Authors: Ruzziconi R. , Sebastiani Giovanni V.
Published: March 2009

The geometrical isomers of 2,3‐difluoro‐2,3‐dihydrobenzofuran have been prepared and their structure assigned on the basis of the nmr spectra. Some suggestions on the conformational situation of two adducts are also reported.
Structure determination of some quinazolone lactones
Authors: Shapiro M. J. , Coppola G. M. , Kahle A. D. , Loosli H. R.
Published: March 2009

A series of quinazolone lactones were prepared and their structures analyzed by 360 MHz proton and carbon‐13 nmr. It was found that the compound capable of lactonization to yield either a six or seven‐membered ring forms only the six‐membered system.
Die umsetzung von azlactonen mit CH‐aciden verbindungen. 2. Mitteil
Authors: Stachel Hans‐Dietrich , Harigel K. Klaus , Poschenrieder Hermann , Burghard Hans
Published: March 2009

Cyanessigester, Malonester, Methansulfonylessigester werden durch Alkylidenazlactone acyliert. Die Primärprodukte kondensieren leicht zu Alkylidentetramsäuren. Die Acylcyanessigester 2 isomerisieren unter dem Einfluß von Säuren zu Aminopyrrolinonen 3.
Nitrosation and hydrolysis studies of some thiazole‐4‐acetic esters
Authors: Campaigne E. , Selby T. P.
Published: March 2009

Nitrosation of hydrazino substituted thiazole‐4‐acetates has been shown to occur on the ring, rather than the α‐methylene carbon, as previously reported. Thus nitrosation of ethyl 2‐isopropylidenehydrazono‐, 2‐benzylidenehydrazono‐, 2‐(2‐benzoylhydrazino)‐, and 2‐(2‐acetylhydrazino)thiazole‐4‐acetates yielded the corresponding 2‐hydrazino‐4‐carbethoxymethylidene‐4,5‐dihydrothiazoline‐5‐oximes. Basic hydrolysis of the thiazoline‐5‐oxime esters, followed by decarboxylation gave tautomeric mixtures of the 2‐hydrazino‐4‐methyl‐2,5‐dihydrothiazoline‐5‐oxime and 2‐hydrazino‐4‐methyl‐5‐nitrosothiazol derivatives. These tautomeric mixtures were also prepared by nitrosating the 2‐hydrazino‐4‐methylthiazoles.

The α,β‐unsaturated acids, 2‐isopropylidenehydrazono‐, 2‐benzylidenehydrazono‐, and 2‐(2‐benzoyl‐hydrazino)‐4‐carboxymethylidene‐4,5‐dihydrothiazoline, were isolated after basic hydrolysis of the corresponding 2‐hydrazinothiazole‐4‐acetic esters. Dinitrosation of the 2‐isopropylidenehydrazono‐4‐carboxy‐methylidene‐4,5‐dihydrothiazoline, followed by decarboxylation, generated 2‐isopropylidenehydrazono‐5‐nitrosothiazole‐4‐formyloxime.
Mass spectral fragmentation pattern of 3‐methyl‐4‐arylaminomethyleneisoxazol‐5‐ones
Authors: Keats N. G. , Summers L. A.
Published: March 2009

The mass spectral fragmentation patterns of 3‐methyl‐4‐arylaminomethyleneisoxazol‐5‐ones obtained by electron impact have been elucidated. The base peaks are due to the molecular ions. The main fragmentation routes involve loss of H, OH, H2O, CO2 and COOH from the molecular ions as well as rupture of the exocyclic CH‐NH bond.
Novel chlorinatin of the 1,3,4‐thiadiazole ring
Authors: Dixon D. D. , Ford M. E.
Published: March 2009

Thermal extrusion of sulfur dioxide from 1‐methyl‐3‐(5‐chlorosulfonyl‐1,3,4‐thiadiazol‐2‐yl)urea (1) provides 1‐methyl‐3(5‐chloro‐1,3,4‐thiadiazol‐2‐yl)urea in quantitative yield.
Synthesis of 3,9‐dihydro‐3,9‐dioxo‐2H‐indeno[2,1‐c] pyridine‐4‐carbonitriles
Authors: Chorvat Robert J. , Desai Bipin N.
Published: March 2009

The annelation of α‐pyridones to five membered ring systems is demonstrated by the synthesis of a series of 2‐azafluorenones. These tricyclic heterocycles could be optionally substituted with methyl or phenyl groups by varying the orthoester reagent in the cyclization reaction. The conversion of the resultant cyanopyridones to pyridonecarboxamides and their N‐methyl homologs is also described.
Halogenation of isoflavones using thionyl and sulphuryl chlorides
Authors: Merchant J. R. , Martyres G.
Published: March 2009

The reactions of thionyl and sulphuryl chlorides on isoflavones have been found to give a number of new chloroisoflavones and isoflavanones, whose structures have been elucidated on the basis of their spectral analytical data.
Azines polycycliques. (IV). Synthèse de dérivés sulfurés en —3 de l'imidazo[1,5‐a]pyridine
Authors: Bourdais Jacques , Rajniakova Olga , Povazanec Frantisek
Published: March 2009

La dihydro‐2,3 imidazo[1,5‐a]pyridinethione‐3 est ‐préparée aisément à partir de l'aminométhyl‐2 pyridine et est ensuite S‐alkylée ou ‐aralkylée. On décrit, dans le cas du dérivé 3‐thiométhylé, la trifluoroacétylation en ‐1,l'oxydation en méthylsulfone et l'hydrolyse des trifluorocétones en acides alkylthio‐3 et alkylsulfonyl‐3 imidazo[1,5‐a]pyridine carboxyliques‐1.
Synthesis of 6‐aryl‐1,3‐dimethyl‐6,7‐dihydro‐6‐azalumazin‐7‐(6H)ones and their conversion into 2‐aryl‐1,2,4‐triazine‐3,5‐(2H,4H)odiones. A new synthesis of 1‐aryl‐6‐azauracils
Authors: Yoneda Fumio , Higuchi Masatsugu
Published: March 2009

Treatment of 6‐amino‐5‐arylazo‐1,3‐dimethyluracils with urea or N,N′‐carbonyldiimidazole gave the respective 6‐aryl‐1,3‐dimethyl‐6,7‐dihydro‐6‐azalumazin‐7‐(6H)ones, which were hydrolyzed with alkali to afford 2‐aryl‐2,3,4,5‐tetrahydro‐3,5‐dioxo‐1,2,4‐triazine‐6‐carboxylic acids (1‐aryl‐6‐azauracil‐5‐carboxylic acids). Thermal decomposition of these carboxylic acids gave the corresponding 2‐aryl‐1,2,4‐triazine‐3,5‐(2H,4H)diones (1‐aryl‐6‐azauracils). Methylation of the latter with methyl iodide gave the corresponding 2‐aryl‐4‐methyl‐1,2,4‐triazine‐3,5‐(2H,4H)diones (1‐aryl‐3‐methyl‐6‐azauracils).
A dipole moment study of annular tautomerism in 5‐p‐tolyltetrazole
Authors: Lumbroso H. , Curé J. , Butler R. N.
Published: March 2009

The electric dipole moment of 5‐(p‐tolyl)tetrazole in dioxane at 30.0° (4.99 D) suggests that the compound is a mixture of the 1H‐tautomer (60 ± 10%) and the 2H‐tautomer (40 ± 10%) in this medium. This determination was made by taking μ (2H) as μ (2Me) = 2.41 D in benzene, and by taking μ (1H) as μ (1Me) = 6.03 D in benzene with due allowance being made for the presence of interannular conjugation in the 1H‐tautomer but not in the 1‐methyl isomer. The dipole moments of 1‐methyl‐5‐(p‐tolyl)tetrazole and 2‐methyl‐5‐(p‐tolyl)tetrazole were also measured in dioxane; that of 1,5‐trimethylenetetrazole was measured in benzene. Comparison with relevant data for unsubstituted tetrazole has also been made.
Fluorinated chromenes. III. Synthesis of 3‐fluoro‐2,2‐dimethyl‐2H‐chromenes
Authors: Camps F. , Coll J. , Messeguer A. , Pericás M. A.
Published: March 2009

The reaction of 2‐fluoro‐1,1‐dimethoxy‐3‐methylbut‐2‐ene (3) with phenols in dry pyridine leads to 3‐fluoro‐2,2‐dimethyl‐2H‐chromenes. 3‐Fluoro analogues of the natural insect antijuvenile hormones Precocene I (1a) and II (1b) have been prepared by this method.
Synthesis and epimerization studies of 1‐alkyl‐2‐carbomethoxy‐(benzyloxy)‐4‐methylazetidines
Authors: Soriano David S. , Podraza Kenneth F. , Cromwell Norman H.
Published: March 2009

A number of 1‐alkyl‐2‐carbomethoxy(benzyloxy)‐4‐methylazetidines have been prepared by reaction of primary amines with α,γ‐dibromo esters. Only one isomer was isolated from the reaction mixture. α‐Aminolactones can also be obtained as the minor product of the reaction sequence.
Synthesis of the 3‐methyl and 4‐methyl derivatives of 3‐amino‐3,4‐dihydro‐1‐hydroxycarbostyril and related compounds
Authors: Davis Alvie L. , Tabb David L. , Swan Janet K. , Mccord Tommy J.
Published: March 2009

The 3‐methyl and 4‐methyl derivatives of 3‐amino‐3,4‐dihydro‐1‐hydroxycarbostyril were synthesized by the reductive cyclization of α‐methyl‐β‐(o‐nitrophenyl)alanine and α‐amino‐β‐(o‐nitrophenyl)butyric acid hydrohalides, respectively, under conditions of catalytic hydrogenation in acidic solution. The free bases of the latter two o‐nitroaromatic amino acids were also catalytically hydrogenated under neutral conditions to yield the respective α‐methyl‐β‐(o‐aminophenyl)alanine and α‐amino‐β‐(o‐aminophenyl)butyric acid which were converted to the corresponding lactams, 3‐methyl‐ and 4‐methyl‐3‐amino‐3,4‐dihydrocarbostyrils. α‐Methyl‐β‐(o‐nitrophenyl)alanine was obtained by acid hydrolysis of 5‐methy)‐5‐(o‐nitrobenzyl)hydantoin which was prepared by treatment of o‐nitrophenylacetone with potassium cyanide and ammonium carbonate. α‐Amino‐β‐(o‐nitrophenyl)butyric acid was synthesized by condensation of α‐bromo‐o‐nitroethylbenzene with diethyl acetamidomalonate, followed by acid hydrolysis of the condensation product. The 4‐methylated compounds were obtained as synthetic mixtures of two diasteromeric racemates in nearly the same amounts as shown by nmr spectral analysis. Unlike the demethylated parent compound, 3‐amino‐3,4‐dihydro‐1‐hydroxycarbostyril, neither the 3‐methyl nor 4‐methyl analog was found to possess any antibacterial activity.
Studies on the synthesis of heterocyclic compounds. Part IV. Further investigation of the pschorr reaction with some pyrazole derivatives
Authors: Daidone Giuseppe , Plescia Salvatore , Fabra Jole
Published: March 2009

Thermal decomposition of the diazonium sulfate derived from N‐methyl‐(1‐phenyl‐3‐methylpyrazol‐5‐yl)‐2‐aminobenzamide afforded products formulated as 1‐phenyl‐3‐methyl[2]benzopyrano[4,3‐c]pyrazol‐5‐one (yield 10%), 1,4‐dimethyl‐3‐phenylpyrazolo[3,4‐c]isoquinolin‐5‐one (yield 10%), N‐methyl‐(1‐phenyl‐3‐methylpyrazol‐5‐yl)‐2‐hydroxybenzamide (yield 8%) and 4′‐hydroxy‐2,3′‐dimethyl‐1′‐phenylspiro[isoindoline‐1,5′‐[2]‐pyrazolin]‐3‐one (yield 20%). Decomposition of the diazonium sulfate derived from N‐methyl‐(1,3‐diphenylpyrazol‐5‐yl)‐2‐aminobenzamide gave products formulated as 7,9‐dimethyldibenzo[e,g]pyrazolo[1,5‐a][1,3]‐diazocin‐10‐(9H)one (yield 8%), 4‐methyl‐1,3‐diphenylpyrazolo[3,4‐c]isoquinolin‐5‐one (yield 7%) and 4′‐hydroxy‐2‐methyl‐1′,3′‐diphenylspiro[isoindoline‐1,5′‐[2]pyrazolin]3‐one (yield 10%).

The spiro compounds 6a,b underwent thermal and acid‐catalysed conversion into the hitherto unknown 2‐benzopyrano[4,3‐c]pyrazole ring system 7a,b in good yield. Analytical and spectral data are presented which supported the structures proposed.
Studies on imidazole derivatives and related compounds. I. Synthesis of novel antineoplastic derivatives of 4‐carbamoylimidazolium‐5‐olate
Authors: Tarumi Y. , Takebayashi Y. , Moriguchi K. , Atsumi T. , Fukumaru T. , Yamamoto H.
Published: March 2009

Acylation of 4‐carbamoylimidazolium‐5‐olate (2) with a variety of acid chlorides produced 4(5)‐carbamoyl‐1H‐imidazol‐5‐(4)yl acid carboxylates (3a‐j). Treatment of esters 3a,c with sodium hydroxide gave imides, 4a,c. Methylation of 3a and 2 with diazomethane gave the N‐3 methyl derivative (6) and a mixture of the N‐3, O‐dimethyl derivative (9), the N‐1, N‐3‐dimethyl derivative (10) and the O‐methyl derivative (11), respectively. 5‐Carbamoyl‐1‐methylimidazolium‐4‐olate (7) and its 4‐carbamoyl isomer (16) were prepared from 2‐aminopropanediamides 8 and 15, respectively. Treatment of the imidazolium compound (10) with aqueous potassium hydroxide gave the recyclized product, 1‐methyl‐5‐methylcarbamoylimidazolium 4‐olate (18). Methyl derivatives 6, 7, and 9 except 16 demonstrated the complete lack of antitumor activity against Lewis lung carcinoma or sarcoma 180 in mice.
Transformations of some 6‐ and 7‐substituted 1,2,3‐benzothiadiazoles
Authors: Leniĉ M. , Merslaviĉ M. , Polanc S. , Stanovnik B. , Stavber H. , Struna D. , Tiŝler M.
Published: March 2009

The preparation of some 6‐ and/or 7‐substituted derivatives of 1,2,3‐benzothiadiazole is described. The reactivity of some compounds was investigated in view of the possibility that 1,2,3‐benzothiadiazoles may behave as masked diazo compounds. 7‐Diazo or diazonium compounds were prepared but no interaction with the thiadiazole part could be observed.
Etude dans la série des pyrrolidinones. IV. Formation de quelques dérivés de l'acide L méthylène bis N‐(oxo‐5 pyrrolidine carboxylique‐2)
Authors: Miquel Christian , Pigache Pierre , Rigo Benoit , Kolocouris Nicolas
Published: March 2009

En partant de l'acide oxo‐5 pyrrolidine carboxylique‐2 facilement accessible, le diacide L méthylène bis N‐(oxo‐5 pyrrolidine carboxylique‐2) est préparé, et transformé en diamine puis en deux diols isomères, qui se cyclisent en un seul ether à qui la configuration méso est attribuée. La réduction des deux diols et de l'éther est totale et conduit à la méthylène bis N‐pyrrolidine.
Novel heterocycles. Synthesis of the 2,4,3‐benzodiazaphosphepine ring system
Authors: Lemke Thomas L. , Boring Daniel
Published: March 2009

Novel alkyl (1,2,4,5‐tetrahydro‐3H‐2,4,3‐benzodiazaphosphepin‐3‐yl)carbamate‐P‐oxides (7) were synthesized by cyclization of the corresponding dichlorophosphinylcarbamates (5) with α,α'‐diamino‐o‐xylene (6). A steric limitation in the synthesis of analogs is discussed.
Synthesis of 4‐piperidazinethiols as potential antiradiation agents
Authors: Kornet Milton J. , Daniels Ralph
Published: March 2009

The free radical addition of thioacetic acid to 1,2‐dicarbethoxy‐1,2,3,6‐tetrahydropyridazines gave high yields of 1,2‐dicarbethoxy‐4‐S‐thiolacetoxypiperidazines. The latter compounds served as the key intermediates in the preparation of 4‐piperidazinethiols. The thiolacetoxy derivatives were partially hydrolyzed to afford the related 1,2‐dicarbethoxy‐4‐piperidazinethiols. Complete hydrolysis of the thiolacetates gave rise to 4‐piperidazinethiols. Finally, lithium aluminum hydride reduction of the thiolacetoxy esters produced a series of 1,2‐dimethyl‐4‐piperidazinethiols. Only 4‐piperidazinethiol hydrochloride showed appreciable anti‐radiation activity.
Pyrimidones. 2. Synthesis and reactions of 2‐chloropyrimidines
Authors: Coppola Gary M. , Hardtmann Goetz E. , Huegi Bruno S.
Published: March 2009

The treatment of 1‐alkyl‐5‐aryl and 1‐alkyl‐4,5‐diaryl‐2‐(1H)pyrimidones with phosphorus oxychloride and phosphorus pentachloride resulted in chlorination and dealkylation to furnish 2‐chloro‐5‐aryl (or 4,5‐diaryl)‐pyrimidines. These chlorpyrimidines were reacted with a variety of nitrogen, oxygen, sulfur, and carbon nucleophiles to produce the corresponding 2‐substituted pyrimidines. In the case of phenyllithium, attack occurred at the 4‐position of the pyrimidine ring yielding 11. Triazolopyrimidine 9 was synthesized via the treatment of 2d with hydrazine followed by reaction with triethyl orthoformate.
Carbon‐13 and proton NMR studies of 1,4‐benzodiazepines
Authors: Haran R. , Tuchagues J. P.
Published: March 2009

One bond and long range 1H‐1H, 1H‐19F, 13C‐1H and 13C‐19F coupling constants for six 1,4‐benzodiazepines are described. An unambiguous assignment of their carbon‐13 resonances is carried out based on chemical shift theory and on the analysis of the fine splittings caused by one bond and long range couplings. Chemical shift and coupling constant values are reported for diazepam, chlordiazepoxide, oxazepam, nitrazepam, chlonazepam and flunitrazepam.
Reaction of nitriles under acidic conditions. Part I. A general method of synthesis of condensed pyrimidines
Authors: Dave K. G. , Shishoo C. J. , Devani M. B. , Kalyanaraman R. , Ananthan S. , Ullas G. V. , Bhadti V. S.
Published: March 2009

Nitriles are known to give rise to salts of different compositions with halogen acids. Many of the reactions undergone by nitriles under the influence of halogen acids are, in many cases, assumed to proceed via the intermediate formation of highly reactive imidoyl derivatives. The intermediates produced, in situ, by the reaction of nitriles with hydrogen chloride should, in principle, be capable of reacting with compounds containing appropriately placed nucleophilic and electrophilic centers leading to the formation of a heterocycle incorporating the C=N of the nitrile. Thus, the reaction of aliphatic, aromatic and heterocyclic nitriles with a variety of ortho aminocarbonyl derivatives such as nitriles, amides, esters and ketones of benzene, thiophen, furan, pyrrole, benzothiophene and pyridothiophene have been found to yield the corresponding condensed pyrimidines in fair to good yields. This constitutes a facile and versatile one‐pot synthesis of condensed pyrimidines.
A novel oxamide rearrangement
Authors: Peet Norton P. , Sunder Shyam , Barbuch Robert J.
Published: March 2009

An efficient, base‐induced rearrangement of 2‐[(1,2‐dioxo‐2‐(methylamino)ethyl)phenylamino]benzoic acid methyl ester (7a) to the isomeric 2‐[(1,2‐dioxo‐2‐(phenylamino)ethyl)methylamino]benzoic acid methyl ester (27a) is described. This novel rearrangement must proceed through a spiro intermediate wherein benzoate is acting as a Michael receptor. When 2‐[(1,2‐dioxo‐2‐(methylamino)ethyl)methylamino]benzoic acid methyl ester (28)‐an oxamide which would produce a degenerate spiro intermediate — was subjected to rearrangement conditions, the product obtained was 1,3‐dimethyl‐2,4‐(1H,3H)quinazolinedione (29). This latter transformation may have proceeded via a benzodiazepinetrione intermediate.
Reactions of 2‐acyl‐1,3‐indandiones
Authors: Lemke Thomas L. , Parker George R.
Published: March 2009

2‐Pivaloyl‐1,3‐indandione reacts with thiosemicarbazide in aqueous base, through two successive retro‐Claisen reactions, to yield 1‐hydroxy‐4‐methylphthalazine. The mechanism of this reaction is described. Under similar conditions, 2‐benzoyl and 2‐acetyl‐1,3‐indandione, did not undergo the same reaction, a steric factor is considered.
Reactions of o‐aminonitriles with isocyanates. 1. A two‐step synthesis of 2,6‐dihydroimidazo[1,2‐c]quinazolin‐5‐(3H)one
Authors: Papadopoulos Eleftherios Paul
Published: March 2009

The reaction of anthranilonitrile with 2‐chloroethyl isocyanate yields 2‐[3‐(2‐chloroethyl)ureido]benzo‐nitrile (6) which, upon heating, or treatment with base, undergoes a double cyclization to form 2,6‐dihydroimidazo[1,2‐c]quinazolin‐5‐(3H) one (8) in excellent yield. When heated with hydrochloric acid, 6 is converted initially into 2‐(2‐chloroethylamino)‐4H‐[3,1]benzoxazin‐4‐one (18) and further into 3‐(2‐chloroethyl)‐2,4‐(1H,3H)quinazolinedione (15). The acid‐catalyzed reaction of 2,3‐dihydro‐5H‐oxazolo[2,3‐b]quinazolin‐5‐one (14) with nucleophilic reagents yields 3‐substituted 2,4‐(1H,3H)quinazolinediones.
Preparation of 4‐aryl‐1,2,3,4‐tetrahydro‐3,3‐dimethylisoquinolines and 1,2,3,4‐tetrahydro‐3,3‐dimethyl‐4‐phenylbenz[h]isoquinolines
Authors: Bobowski George , Gottlieb Jeffrey M. , West Barbara
Published: March 2009

Synthetic procedures to prepare a number of 4‐aryl‐1,2,3,4‐tetrahydro‐3,3‐dimethylisoquinolines and their benzo‐homogues 3 through a series of intermediates are described. The condensation of α‐(1‐amino‐1‐methylethyl)arylmethanols 5 with arylaldehydes 6 gave imino derivatives 7 which on reduction with borohydride gave secondary amines 8. The treatment of 8 with mineral acids gave the target compounds 3. Biological activities of 3 are briefly discussed.
The synthesis of 5,6‐dimethoxycyclopentano[h]‐isoquinoline and derivatives
Authors: Solomons William E. , Mathison Ian W.
Published: March 2009

The synthesis of the previously unreported 5,6‐dimethoxycyclopentano[h]isoquinoline (1) by way of a Pomeranz Fritsch ring closure of the diethyl acetal of 4,5‐dimethoxy‐7‐indanylidene aminoacetaldehyde (3) is reported. Acetylation of the N‐oxide of 1 yielded the corresponding N‐acetyl‐1‐isoquinolone, which readily converted to the 1‐isoquinolone on exposure to atmospheric moisture. Several diesters of the dihydroxy analog of 1 are reported.
Identification ofN‐methylpyrazole analog isomers by13C NMR
Authors: Agnew Marc N. , Bauer Victor J. , Effland Richard C.
Published: March 2009

Using severalN‐methyl pyrazole analogs the utility of13C nmr in determining isomeric structures was examined. The chemical shift assignments of the pyrazole carbons and thus the isomeric structures were determined using a combination of proton coupled and proton decoupled13C nmr spectra.
Merocyanine dyes from 4‐dicyanomethylene‐2,6‐dimethyl‐4H‐pyran
Authors: Van Allan J. A. , Reynolds G. A.
Published: March 2009

Neutral dyes were prepared by reacting 1‐ethyl‐2[2‐(N‐methylanilino)vinyl]quinolinium iodide with 4‐dicyanomethylene‐2,6‐dimethyl‐4H‐pyran and then condensing the resulting product with an aromatic aldehyde.
Studies in the heterocyclic series. XVIII. Utilization of 4‐aminopyrimidine chemistry in 1,4,7,9‐tetraazabenzo[b]phenothiazine synthesis
Authors: Okafor Charles O.
Published: March 2009

The synthesis of 1,4,7,9‐tetraazabenzo[b]phenothiazine ring system from 4‐aminopyrimidine is reported. This new heterocyclic ring was obtained by converting a 4‐aminopyrimidine to the corresponding 5‐thiocyanato derivative followed by hydrolysis and subsequent treatment with 2,3‐dichloroquinoxaline. Several derivatives were obtained by using suitable substituted starting materials. Nitration with mixed nitric and sulfuric acids gave the corresponding 13‐nitro derivatives. Spectral analyses are in agreement with the assigned structures.
Reaction of alkoxyuridines with ammonia
Authors: Mathews Robert A. , Stöhrer Gerhard
Published: March 2009

2‐Alkoxy‐ and 4‐alkoxyuridines were converted into isocytidine and cytidine by reaction with ammonia at room temperature. Reaction with hydrogen sulfide produced 2‐thio‐ and 4‐thiouridine but the reaction was incomplete. The reaction may be helpful in the identification of alkylated pyrimidine nucleosides in DNA.
Synthesis of 11‐deoxy‐5,6‐didehydro‐13,14‐dihydro‐8‐azaprostaglandin E1
Authors: Zoretic P. A. , Jardin J. , Angus R.
Published: March 2009

The synthesis of 11‐deoxy‐5,6‐didehydro‐13,14‐dihydro‐8‐azaprostaglandin E1 is reported. The effects of the 8‐aza‐PGE1 analog on human bronchial muscle and its antisecretory activity is also reported.
Condensation of 2‐aminophenols and α‐dicarbonyl compounds. Part 4. Dibenzoxazolines substituted with heterocycles
Authors: Belgodere E. , Bossio R. , Parrini V. , Pepino R.
Published: March 2009

The tautomeric structure of 2,2′‐dibenzoxazolines 2′‐substituted with heterocycles was investigated by ir, pmr and uv spectroscopy.
N‐Alkyl derivatives of trans‐6,7‐dihydroxy‐1,2,3,4,4a,5,10,10b‐octahyrobenzo[g]quinoline A congener of apomorphine lacking the non‐oxygenated aromatic ring
Authors: Cannon Joseph G. , Lee Teresa , Beres James A. , Goldman H. Duane
Published: March 2009

A synthetic sequence leading to the title compounds began with methyl 5,6‐dimethoxy‐2‐tetralone‐3‐carboxylate and involved a multi‐step construction of the heterocyclic ring. The trans‐fused isomer was isolated from the cyclization step. However, the possibility of formation of some cis‐fused isomer cannot be precluded.
Synthesis of (4S,9aS)‐hexahydro‐4‐methyl‐1H,5H‐pyrrolo[2,1‐c][1,4]‐thiazepine‐1,5‐dione, A potent angiotensin converting enzyme inhibitor
Authors: Kim Dong Han
Published: March 2009

Synthesis of (4S,9aS)‐hexahydro‐4‐methyl‐1H,5H‐pyrrolo[2,1‐c][1,4]thiazepine‐1,5‐dione, an orally active potent angiotensin converting enzyme inhibitor is described.
Deoxygenation and X‐ray photoelectron studies on some quinoxalines and their N‐oxides
Authors: El‐Abadelah Mustafa M. , Anani Ali A. , Khan Zahida H. , Hassan A. M. , Katrib Ali
Published: March 2009

Deoxygenation results of some quinoxaline dioxides with phosphorous trichloride are presented and compared with previous deoxygenations with other reagents. Differentiation between isomeric quinoxaline oxides using X‐ray photoelectron spectroscopy is also discussed.
A convenient route to α‐amido‐β‐lactams
Authors: Bose Ajay K. , Manhas M. S. , Gala K. , Sahu D. P. , Hegde V.
Published: March 2009

Dedicated to Professor John C. Sheehan on the occasion of his sixty‐fifth birthday.

A method for the synthesis of α‐amido‐β‐lactams without the intermediacy of an α‐amino‐β‐lactam is described. The appropriate β‐keto ester is used for preparing a vinylamino β‐lactam via a “Dane salt” by a previously reported method. Oxidation with ruthenium tetroxide and periodic acid of this product leads directly to the desired “V”, or “G” or analogous α‐amido side chain.
Quinazolines and 1,4‐Benzodiazepines. XC. 2‐Aminoimidazo[1,5‐a][1,4]benzodiazepin‐1‐ones and derivatives
Authors: Walser Armin , Flynn Thomas
Published: March 2009

The addition of diethyl azodicarboxylate to an electron rich double bond was employed as the key step for the preparation of the title compounds. Novel tetracyclic [1,2,4]triazino[1′,6′:3,4]imidazo[1,5‐a][1,4]benzodiazepines were accessible from these 2‐aminoimidazo[1,5‐a][1,4]benzodiazepin‐1‐ones.
Synthesis and mass spectral studies of a coumarin analog of chloramphenicol
Authors: Bevinakatti Hanamanthsa S. , Badiger Virupax V.
Published: March 2009

Preparation of dl‐threo‐2‐dichloroacetamido‐1‐(3‐coumarinyl)propane‐1,3‐diol (7) is discussed. The structures of the final compound (7) as well as its two precursors (5 and 6) were confirmed by ir and nmr studies. Because of the larger side chain, the coumarin analog (7) breaks down in a well defined manner upon electron impact. Its mass spectral fragmentation patterns are described.
Synthesis of heterocycles. Part II. New routes to acetylthiadiazolines and alkylazothiazoles
Authors: Eweiss N. F. , Osman A.
Published: March 2009

Methylglyoxalyl chloride arylhydrazones (III) react with an ethanolic solution of thiourea to give 2‐amino‐4‐methyl‐5‐arylazothiazoles (XII) instead of the expected 2‐acetyl‐4‐aryl‐5‐imino‐Δ2‐1,3,4‐thiadiazolines (V) which were obtained from III and potassium thiocyanate. 3‐Thiocyanato‐2,4‐pentanedione (IV) coupled with diazotized anilines to give V. The postulated routes to formation of V and XII from III are given. Nitrosation of V gave the corresponding N‐nitroso derivatives (VI) which decomposed upon refluxing in dry xylene to give 2,4‐disubstituted‐Δ2‐1,3,4‐thiadiazolin‐5‐ones (VII). Boiling of either V or VI with hydrochloric acid gave the hydrochloride salt (VIII). The thiadiazolines V gave the respective N‐acyl derivatives (IX) and (X) with acetic anhydride and benzoyl chloride in pyridine.
Syntheses of 2‐arylimidazole derivatives through annelations employing benzylamines
Authors: Veronese A. C. , Cavicchioni G. , Servadio G. , Vecchiati G.
Published: March 2009

Annelations of benzylamines with hydroximino derivatives of pentane‐2,4‐dione or of alkyl acetoacetates, acetoacetamides, and acetoacetanilides, afford imidazole derivatives and provide easy incorporation of the benzylic carbon and nitrogen in the heterocycle. The limits of the reaction have been explored.
A novel pentacyclic pyridine dilactone. 7‐methyl[1]benzopyrano[4,3‐d][1]benzoxacino[4,3‐b]pyridine‐6,16‐dione
Authors: Rajyalakshmi K. , Srinivasan V. R.
Published: March 2009

When equimolar quantities of salicylaldehyde 2 and ethyl 3‐amino‐2‐butenoate 3 or its constituents (ethyl 3‐oxobutanoate and ammonia) were refluxed on a steam‐bath for 6 hours with a trace of acetic acid, two products, a pentacyclic pyridine dilactone 4 and 3‐acetyl coumarin 5, resulted in 15% and 45% yields, respectively. The structure of 4 was elucidated as 7‐methyl[1]benzopyrano[4,3‐d][1]benzoxacino[4,3‐b]‐pyridine‐6,16‐dione on the basis of its spectral data. The mechanism of its formation has been discussed. The reaction has been extended to three more substituted salicylaldehydes.