bluuebunny/crossref_metadata_2025 huggingface dataset:
Titanium(III) chloride and electrochemical reduction of pyrazine, quinoxaline and triazine derivatives and of their salts
Authors: Armand J. , Chekir K. , Pinson J.
Published: March 2009

The reduction of pyrazine, quinoxaline and triazine derivatives by titanium(III) chloride leads to di‐ or tetrahydrogenated compounds. High yields of tetrahydro compounds are also obtained through the reduction of quinoxalinium salts. These results are compared with those obtained by electrochemical reduction.
Reactions of 4‐chloroacetoacetic esters with thioureas
Authors: Campaigne E. , Selby T. P.
Published: March 2009

Several heterocyclic acetic acids and esters were synthesized by allowing the appropriate thiourea, ethylenethiourea or trimethylenethiourea to react with 4‐chloroacetoacetic esters, followed by acid hydrolysis to the hydrochlorides of the free acids. Both esters and acids of 2‐aminothiazole‐4‐acetic acid, 5,6‐dihydro‐imidazo[2,1‐b]thiazole‐3‐acetic acid and 6,7‐dihydro‐5H‐thiazolo[3,2‐c]pyrimidine‐3‐acetic acid were obtained.
Selective reduction of nitro‐heterocycles with sodium sulfide in aqueous p‐dioxane
Authors: Lin Yang‐I , Lang S. A.
Published: March 2009

Nitro‐heterocycles, particularly those containing halogen, were selectively reduced with sodium sulfide in aqueous p‐dioxane to give the corresponding amino‐heterocycles in 70‐89% yields.
Evidence for conformational isomerism. II. Synthesis of 1‐alkyl‐2‐carboazetidines using organolithium reagents
Authors: Cromwell Norman H. , Podraza Kenneth F. , Soriano David S. , Rodebaugh Richard M.
Published: March 2009

Treatment of 1‐alkylazetidine‐2‐carboxylic acids with several organolithium reagents leads to the corresponding 1‐alkyl‐2‐carboazetidines in near quantitative yield. Additional evidence is presented for conformational isomerism in the title compounds on the basis of infrared carbonyl stretching frequencies.
Synthesis of pyrimido [4,5‐c] pyridazine (4‐deazafervenulin), pyrazolo[3,4‐d] pyrimidine and 6‐(pyrazino‐1‐yl)pyrimidine derivatives
Authors: Ram Vishnu J. , Pandey Hrishi Kesh , Vlietinck Arnold J.
Published: March 2009

The synthesis of several pyrimido[4,5‐c]pyridazine (4‐deazafervenulin) (1), pyrazolo[3,4‐d]‐pyrimidine (2) and 6‐(pyrazino‐1‐yl)pyrimidine (9) analogs has been accomplished from 6‐hydrazinouracil (3). This compound could not be used as starting material for the preparation of indolo[3,2‐c]pyridazino[3,4‐d]pyrimidine derivatives (8) because it yielded the corresponding hydrazones (7).
The photolysis of 1‐benzyloxy‐1,2,3‐benzotriazole
Authors: Feld W. A. , Paessun R. , Servé M. P.
Published: March 2009

1‐Benzyloxy‐1,2,3‐benzotriazole was photolyzed and found to yield benzaldehyde and azobenzene as the principal products.
The synthesis of some substituted macrocyclic polyether‐diester compounds with the malonyl moiety
Authors: Bradshaw Jerald S. , Jolley Scott T. , Jones Brian A.
Published: March 2009

A series of seven substituted macrocyclic polyether‐diester compounds containing the malonyl moiety have been prepared.
A new mesoionic species in the synthesis of some 5‐thioxo‐1,2,4‐triazolin‐3‐ones
Authors: Ziman S. D.
Published: March 2009

In the course of preparing some 1,2‐dialkyl‐4‐aryl‐5‐thioxo‐1,2,4‐triazolin‐3‐ones (III) (1), we were looking for a route which would eliminate the problem associated with (a) preparation of 1,2‐dialkyl hydrazines and (b) specificity in addition to the isothiocyanate or isocyanate when the alkyl groups were not the same.
Sur la synthèse d'acides thiazolotriazolylacétiques
Authors: Moskowitz H. , Mignot A. , Miocque M.
Published: March 2009

Lors de la préparation d'acides thiazolotriazolylacétiques, la condensation du chloro‐4 oxo‐3 butyrate d'éthyle avec les triazolinethiones a été étudiée. En présence d'un agent basique (triéthylamine) on observe exclusivement la S‐alkylation au lieu de la cyclisation attendue. En présence d'agents acides (oxychlorure de phosphore, acide chlorhydrique), le β‐cétoester formé se cyclise en dérivé thiazolotriazolylacétique.
Studies on phenothiazines. Part 7. Synthesis of 3‐substituted 2‐aminobenzenethiols and their conversion into phenothiazines
Authors: Gupta R. R. , Ojha K. G. , Kumar M.
Published: March 2009

Synthesis of substituted 1‐nitrophenothiazines is reported by the Smiles rearrangementin situ, which involves condensation of 3‐chloro or methyl‐2‐aminobenzenethiol witho‐halonitrobenzenes (2,4,6‐trinitochloro‐benzene, 1,4‐dichloro‐2,6‐dinitrobenzene, 2,4,6‐tribromo‐1,3‐dinitrobenzene) in the presence of ethanolic sodium hydroxide. Ir and mass spectral studies are included.
Potential anticonvulsants. III. The condensation of isatin with cyclic ketones
Authors: Popp F. D. , Parson R. , Donigan B. E.
Published: March 2009

Isatin has been condensed with a series of cyclic ketones to give 3‐substituted‐3‐hydroxyoxindoles as potential anticonvulsant agents.
Préparation de cétals cycliques à plus de sept chaǐnons
Authors: Einhorn Jacques , Bacquet Cathy , Lelandais Daniel
Published: March 2009

Nous décrivons une méthode de synthèse efficace de cétals cycliques à huit chaǐnons ou plus dont plusieurs trioxocannes. Cette méthode fait intervenir la réaction directe d'une cétone sur un substitut d'orthoester.
A revision of the synthesis of some polycyclic systems related to benzoheteroquinolizidines
Authors: Galvez C. , Garcia F. , Ribera J. , Viladoms P.
Published: March 2009

The preparation of 3‐methoxycarbonyl‐N‐2‐(3‐benzo[b]thienyl)ethylpyridinium bromide, 5‐methoxy‐carbonyl‐N‐2‐(3‐benzo[b]thienyl)ethyl‐1,2,3,4‐ tetrahydropyridine and (1RS,12bRS)‐1‐methoxycarbonyl(benzo‐[b]thienyl[2,3‐a]quinolizidine is described. Some observations dealing with different methods discussed in the literature for the synthesis of such polycyclic systems are reported.
Synthesis of 5‐(1‐naphthylmethyl)‐4‐aryl‐s‐triazol‐3‐thiols/ylthioglycolic acids as possible antiinflammatory agents
Authors: Kothari Paresh J. , Mehlhoff Mark A. , Singh Shiva P. , Parmar Surendra S. , Stenberg Virgil I.
Published: March 2009

Several 5‐(1‐naphthylmethyl)‐4‐aryl‐s‐triazol‐3‐thiols/ylthioglycolic acids were synthesized as possible anti‐inflammatory agents. The interpretation of infrared, nuclear magnetic resonance, and mass spectra is discussed for chemical characterization of these compounds.
Synthesis of some newer 5‐(5‐aryl‐2H‐tetrazol‐2‐ylmethyl)‐4‐substituted‐s‐triazole‐3‐thiols as possible antiinflammatory agents
Authors: Kothari Paresh J. , Singh Shiva P. , Parmar Surendra S. , Stenberg Virgil I.
Published: March 2009

Several 1‐(5‐aryl‐2H‐tetrazol‐2‐ylacetyl)‐4‐substituted thiosemicarbazides and 5‐(5‐aryl‐2H‐tetrazol‐2‐yl‐methyl)‐4‐substituted‐s‐triazole‐3‐thiols were synthesized as possible antiinflammatory agents. These compounds were characterized by their elemental, infrared and nuclear magnetic resonance analysis.
Substitution des 1,2‐diazinsystems mit symm. trioxanylradikalen; ein zugang zu pyridazincarbaldehyden. 13. Mitteilung über pyridazine
Authors: Heinisch Gottfried , Kirchner Ingrid
Published: March 2009

Reaktionen von Pyridazin (1) und 3‐Methyl‐ bzw. 4‐Methylpyridazin (5 bzw. 10) mit symm. Trioxanylradikalen werden untersucht. Verbindung 1 und 5 werden dabei selektiv an den Kohlenstoffatomen 4 und/oder 5 angegriffen, während bei 10 z.T. auch Substitution α zu den Ringstickstoffatomen erfolgt. Aus den als Hauptprodukten resultierenden Mono‐symm. trioxanylderivaten 2, 6, 11 und 12 werden 4‐Pyridazincarbaldehyd und die bisher nicht zugänglichen Formyl‐methylpyridazine 9, 16 und 17 dargestellt.
Reactions of 3‐chloro‐6‐hydrazinopyridazine with michael‐retro‐michael reagents
Authors: Sunder Shyam , Peet Norton P.
Published: March 2009

Although pyrazole formation results from treatment of 3‐chloro‐6‐hydrazinopyridazine (2) with both ethoxymethylenemalononitrile and ethyl (ethoxymethylene)cyanoacetate, 6‐chlorotriazolo[4,3‐b]pyridazine (5) was produced (75% yield) when 2 was treated with diethyl ethoxymethylenemalonate. Treatment of 2 with diethyl acetylmalonate (8) gave both 6‐chloro‐3‐methyltriazolo[4,3‐b]pyridazine (10) and 5‐hydroxy‐3‐methyl‐1‐(6‐chloro‐3‐pyridazinyl)‐1H‐pyrazole‐4‐carboxylic acid ethyl ester (12). Pyrazole 12 was initially isolated as a salt of triazolopyridazine 10.
Effects of proton donors on the electrochemical reduction of benzo[c]cinnoline in acetonitrile
Authors: Millefiori Salvatore
Published: March 2009

The polarographic behaviour of benzo[c]cinnoline in acetonitrile in the presence of various proton donors (water, phenol, benzoic acid and perchloric acid) is reported. In aprotic medium benzo[c]cinnoline is reduced in two one‐electron waves, followed by one two‐electron wave. The most probable final reduction product is 2,2′‐diaminobiphenyl. The addition of proton donors causes a shift and/or appearance of new polarographic waves, which can be related to the reduction of various protonated species.
Preparation and catalytic hydrogenation of 4,6‐dimethyl‐ and 4,7‐dimethyl‐8‐methoxycoumarins. A 4‐methyldihydrocoumarin synthesis
Authors: Mills Frank D.
Published: March 2009

Reduction of the title coumarins at 1500 psi and 150° over 10% palladium on charcoal provides a simple route to dihydrocoumarins and/or ethyl butanoates, hydrogenolysis products of the lactone. Lower pressures and temperatures tend to yield only the dihydrocoumarin. The butanoates are readily converted to the dihydrocoumarins in polyphosphoric acid.
Fused pyrazolopyrimidines. I. Pyrazolo[4,3‐e]‐v‐triazolo[1,5‐a]pyrimidine. A new heterocyclic system
Authors: Khan Misbahul Ain , Freitas Antonio Carlos Carreira
Published: March 2009

5‐Azido‐4‐cyano‐1‐phenylpyrazole reacts with benzylcyanide in the presence of sodium methoxide to give the title ring system.
Synthesis of Bis‐(2‐mercaptoimidazole)‐4,4‐butylidene
Authors: Ashutosh  , Pandey N. D. , Mehrotra J. K.
Published: March 2009

Ethyl butylidene‐bis‐3‐phthalimidoacetoacetate (II) was prepared by condensation of ethyl‐3‐phthalimido‐acetoacetate and n‐butyraldehyde in the presence of piperidine in benzene. Compound II was hydrolysed by hydrochloric acid followed by cyclization with potassium thiocyanate to yield bis(2‐mercaptoimidazole)‐4,4‐butylidene (IV).
Heterocycles from substituted amides. IX. 4,5‐dihydro‐1,2,4‐triazin‐6‐(1H)ones from 2‐isocyanoacetates and hydrazine
Authors: Leschinsky Kindrick L. , Chupp John P.
Published: March 2009

The novel synthesis of 4,5‐dihydro‐1,2,4‐triazin‐6‐(1H)ones, 2, from 2‐isocyanoacetates is described. This synthetic method allows the first synthesis of the unsubstituted parent ring sytem and, in general, gives 2 substituted in only the five position. The assignment of tautomeric structures (2 or 3) to the triazinone products was resolved by spectroscopic means.
Condensation of 2‐aminophenols and α‐dicarbonyl compounds. Part 3. Benzoxazines substituted with heterocycles
Authors: Belgodere E. , Bossio R. , Parrini V. , Pepino R.
Published: March 2009

A series of 1,4‐benzoxazines (I) and 2,2′‐dibenzoxazolines (II) were obtained by condensation of 2‐aminophenol and 2‐amino‐5‐nitrophenol with glyoxal derivatives of the heterocyclic series. The structure of compounds (I) was investigated by uv, pmr and mass spectroscopy.
Annelation of α,β‐unsaturated esters to thian‐3‐one 1‐oxides using dianion of ω‐(methylsulfinyl)acetophenone
Authors: Tamura Yasumitsu , Shindo Hirohisa , Ishibashi Hiroyuki
Published: March 2009

β‐Monosubstituted α,β‐unsaturated esters undergo an annelation with dilithio salt of ω‐(methylsulfinyl)‐acetophenone to produce 5‐substituted 6‐benzoylthian‐3‐one 1‐oxides.
Substitutions‐ und eliminierungsprozesse an 4,5‐dialkyl‐1,2,3‐thiadiazolen
Authors: Meier Herbert , Zimmer Oswald
Published: March 2009

1,2,3‐Thiadiazoles are brominated in the α‐position of the side chain linked on C‐4 or C‐5. Several methods for the dehydrobromination are compared. Besides eliminations, nucleophilic substitutions can be observed. Regioselectivities are discussed concerning the ring closure in the generation of the 1,2,3‐thiadiazoles, the bromination and the SN‐reactions. The most surprising result is the change of the positions of the substituents in the formation of 11b from 4b via an EA‐mechanism involving the intermediate 10b.
Formation of 5‐aroyl‐3‐(2H)isothiazolones from the reaction of 3‐aroylpropionamides with thionyl chloride
Authors: Tsolomitis A. , Sandris C.
Published: March 2009

Reaction of N‐substituted‐3‐aroylpropionamides with excess thionyl chloride was found to give sulfur‐nitrogen heterocyclic compounds, which were characterized as 2‐substituted‐5‐aroyl‐3‐(2H)isothiazolones.
Synthese und umsetzung beidseitig ungleich substituierter neuer monothiobenzile zu 1,3‐oxathiolen
Authors: Bak C. , Praefcke K.
Published: March 2009

Es werden die Synthese neuer Monothiobenzile mit unterschiedlichen Substituenten an beiden Phenylringen sowie deren Reaktionen mit Diazoalkanen unter Bildung von 1,3‐Oxathiolen beschrieben.
Quino[1,2‐c]quinazolines. II. Synthesis of 12,13‐dihydro‐11bH‐quino‐[1,2‐c]quinazolines via the versatile intermediates 2‐(2‐amino‐4,5‐dimethoxyphenyl)‐6,7‐disubstituted‐1,2,3,4‐tetrahydroquinolines
Authors: Phillips Steven D. , Castle Raymond N.
Published: March 2009

The versatile intermediates 2‐(2‐amino‐4,5‐dimethoxyphenyl)‐6,7‐dimethoxy‐1,2,3,4‐tetrahydroquinoline (2a) and 6‐(2‐amino‐4,5‐dimethoxyphenyl)‐5,6,7,8‐tetrahydro[1,3]dioxolo[4,5‐g]quinoline (2b) were used in the preparation of a wide variety of 12,13‐dihydro‐11bH‐quino[1,2‐c]quinazolines by reaction with triethyl orthoformate, cyanogen bromide, urea and carbon disulfide in pyridine. Reaction of the thio and keto products with methyl iodide and phosphorus oxychloride, respectively, gave the requisite methylthio and chloro derivatives. Novel Reissert type reactions occurred when the intermediates 2a,b were reacted with acetic anhydride or benzoyl chloride. The attempted dehydrogenation of 12,13‐dihydro‐2,3,9,10‐tetramethoxy‐11bH‐quino[1,2‐c]quinazoline (3a) is also reported.
Sulfur nitride in organic chemistry. 9. The reaction of tetrasulfur tetranitride with benzyl ketones. Preparation of 3,4‐disubstituted‐1,2,5‐thiadiazoles
Authors: Mataka Shuntaro , Hosoki Akira , Takahashi Kazufumi , Tashiro Masashi
Published: March 2009

The reaction of tetrasulfur tetranitride (1) with various aryl and alkyl benzyl ketones (2a‐o), oxindole (11), benzyl α‐pyridyl ketone (12) and α‐phenacylpyridine (13) afforded the corresponding 1,2,5‐thiadiazoles (3a‐n, 11 and 14). The scope and limitations of the above reaction were investigated and the evidences suggesting the radical anion mechanism are presented.
Heterocyclic quinones with bridgehead nitrogen atoms. Part I. Pyrrolo[1,2‐a]quinoxaline‐6,9‐dione and pyrrolo[2,1‐c][1,2,4]benzotriazine‐6,9‐dione
Authors: Al‐Sammerrai Dhiab A‐J. , Ralph James T. , West David E.
Published: March 2009

The synthesis and some reactions of pyrrolo[1,2‐a]quinoxaline‐6,9‐dione and pyrrolo[2,1‐c][1,2,4]benzotriazine‐6,9‐dione are described.
Synthesis of 8‐demethyl‐8‐hydroxy‐5‐deazariboflavins
Authors: Ashton Wallace T. , Brown Ronald D.
Published: March 2009

1‐Deoxy 1‐(3,4‐dihydro‐8‐hydroxy‐2,4‐dioxopyrimido[4,5‐b]quinolin‐10‐(2H)‐yl)‐D‐ribitol (7,8‐didemethyl‐8‐hydroxy‐5‐deazariboflavin), the flavin moiety of Methanobacterium coenzyme F420, and its 7‐methyl analog were prepared by acid‐catalyzed reaction of appropriately substituted 6‐(N‐D‐ribitylanilino)uracils with trimethyl or triethyl orthoformate followed by deprotection.
A carbon‐13 Nmr assignment study of 3,5‐diarylisoxazoles
Authors: Baumstark Alfons L. , Chrisope Douglas R. , Keel Rebecca A. , Boykin David W.
Published: March 2009

The assignment of the carbon‐13 nmr resonances of 3‐(aryl)‐5‐phenylisoxazoles (I) and 3‐phenyl‐5‐(aryl)‐isoxazoles (II) in dimethylsulfoxide‐d6 has been made. The assignments were made by using model compounds, chemical shift arguments, coupling with fluorine substituents, and shifts resulting from quaternization of the isoxazole ring. A carbon‐13 nmr method for distinguishing between I and II which can be produced simultaneously by certain synthetic methods is presented.
Novel heterocycles. 6. The condensation of ethyl o‐fluorobenzoyl acetate with cyclic imino ethers
Authors: Coppola Gary M. , Damon Robert E.
Published: March 2009

The reaction between ethyl o‐fluorobenzoylacetate and cyclic imino ethers is described. The products, the corresponding 1,2‐fused quinolines (13a‐17a), were isolated in good yields. In one instance the uncyclized condensation intermediate 18 was isolated and characterized.
Chemistry of the phenoxathiins and isosterically related heterocycles. XIII. 13C‐NMR spectroscopy of 1‐azaphenoxathiin 10,10‐dioxide. An unusual perturbation of 1H‐13C coupling constants
Authors: Sejiny Osama M. , Martin Gary E.
Published: March 2009

The total assignment of the 13C‐nmr spectrum of 1‐azaphenoxathiin 10,10‐dioxide is reported based on the utilization of additivity correlations for the conversion of sulfide to sulfone linkages. Although the benzenoid portion of the molecule obeyed standard additivity correlations, substantial deviation in additivity behavior was observed in the pyridyl portion of the molecule. Examination of the 1H‐13C spin‐coupling constants showed a perturbation of the primary one bond (1JCH) couplings of the C‐2 and C‐4 carbons.
2,3,5,6‐tetramethylmorpholine. VI. Cyclization of N‐substituted 3,3′‐iminobis‐2‐butanols
Authors: Hernestam Sven , Stenvall Gillis
Published: March 2009

The cyclization of N‐substituted 3,3′‐iminobis‐2‐butanols to N‐substituted 2,3,5,6‐tetramethylmorpholines in sulfuric acid is studied. The ring closure seems to be exclusively a normal SN2‐type substitution with partial inversion of configuration before the cyclization. The steric influence of the N‐substituents on the SN2‐reaction and on the inversion is discussed.
Synthesis of imidazo[4,5‐b]‐ and [4,5‐c]pyridines
Authors: Middleton Richard W. , Wibberley D. George
Published: March 2009

2‐Arylimidazo[4,5‐b]‐ and [4,5‐c]pyridines have been prepared by treatment of the appropriate 2,3‐ or 3,4‐diaminopyridine with an aromatic carboxylic acid in the presence of polyphosphoric acid. Other derivatives have been prepared by similar cyclisation of diaminopyridines using triethyl orthoformate, urea, thiophosgene and thiourea and the properties of some N‐oxides have been investigated. A number of the arylimidazopyridines have been screened for mutagenicity.
Heterocyclic systems. 1. Synthesis of 5,6,6a,7,8,13‐hexahydroquinoxalino[2,1‐c][1,4]benzodiazepine
Authors: Massa S. , Corelli F. , Stefancich G. , De Martina G.
Published: March 2009

The intramolecular cyclization of 1‐(2‐aminobenzoyl)‐2‐carbethoxy‐3‐oxo‐1,2,3,4‐tetrahydroquinoxaline, followed by lithium aluminum hydride reduction, gave the title compound.
Photochemical transformations of 4,5‐diaryl‐4‐oxazolin‐2‐one protecting groups
Authors: Guziec Frank S. , Tewes Edwin T.
Published: March 2009

The photochemical cleavage of 4,5‐diaryl‐4‐oxazolin‐2‐one protecting groups is discussed as an alternative to reduction or chemical oxidation of the heterocyclic system. Ultraviolet irradiation in air of oxazolinone (1) in methanol leads to photooxygenation of the protecting group, affording the corresponding benzamide and benzoate ester. Reduction of the intermediate photoproduct leads to complete removal of the protecting group. A mechanism for this photolysis is proposed and evidence in support of this mechanism is reported.
1.3‐dipolare additionen an 3.4‐diazatricyclo[4.2.1.02.5]nona‐3.7‐dien und 3.4‐diazatricyclo[4.2.1.02.5]nona‐7‐en‐derivate
Authors: Rieber N. , Böhm H.
Published: March 2009

Die Umsetzung von 3.4‐Diazatricyclononadien 1 und 3.4‐Diazatricyclononen‐Derivaten 2–4 mit 1.3‐dipolaren Agentien führt zu wachstumsregulierenden tetracyclischen Triazolinen 5–8, Isoxazolinen 15–17, Pyrazolinen 18–22 und weiteren Abwandlungsprodukten 9–14 bzw. 23.
Synthesis and reactions of some 5,6,7,8‐tetrahydroquinoxaline derivatives
Authors: Houminer Yoram
Published: March 2009

5,6,7,8‐Tetrahydroquinoxaline derivatives containing an oxygen functionality in the 6‐position were prepared by ring closure of suitable 2,3‐disubstituted pyrazines such as 6 and 12. The chemistry of these novel 5,6,7,8‐tetrahydroquinoxalines is discussed.
The synthesis of 3‐ and 5‐amino‐1,2,4‐oxadiazoles. A caveat
Authors: Dimsdale Michael J.
Published: March 2009

Evidence obtained from a single series of compounds demonstrates the need for care when assigning structures to amino‐1,2,4‐oxadiazoles using the methodology described in the literature. Certain synthetic methods can give rise to different position isomers in different series.
Applications of 13C Nmr spectroscopy to structural assignment of derivatives of 2,3,4,5,6,7‐hexahydro‐1H‐2‐benzazonine
Authors: Benattar André , Barbry Didier , Hasiak Bruno , Couturier Daniel
Published: March 2009

Treatment of 1,1‐dimethyl‐2‐tolylpiperidinium halides with sodium amide in liquid ammonia affords derivatives of 2,3,4,5,6,7‐hexahydro‐1H‐2‐benzazonine via the Sommelet‐Hauser rearrangement. Structures of the reaction products have been established by 13C nmr. In the case of 1,1‐dimethyl‐2‐benzylpiperidinium halide, only an elimination reaction takes place.
Synthesis of some 2‐(N‐protected or free aminoacyl or N‐tosyltripeptide)‐aminophenazines, aminonaphthophenazines and 4‐(N‐protected or free aminoacyl or N‐tosyltripeptide)aminophenazone derivatives
Authors: El‐Naggar A. M. , Ahmed F. S. M. , Badie M. F.
Published: March 2009

The syntheses of different 2‐(N‐tosyl‐ or N‐phthalyl‐ or free aminoacyl or N‐tosyltripeptide)‐aminophenazines, and the corresponding derivatives of 2‐aminonaphthophenazines and some derivatives of 4‐aminophenazones (IV‐XXXIII) are described. Compounds XI‐XIII, XX‐XXIII, XXX‐XXXII, XXXIV‐XXXIX and XL‐XLV were found to be active against a number of microorganisms.
13C NMR spectral analysis of chlorpromazine, chlorpromazine sulfoxide and related models
Authors: Staiger David B. , Warren Richard J. , Zarembo John E. , Post Alex , Anderson Elvin L.
Published: March 2009

The natural abundance carbon‐13 nmr spectra of chlorpromazine, chlorpromazine sulfoxide and related models were obtained and assigned. The chemical shift effects from sulfoxidation of the carbon skeleton will be discussed. Assignments were made on the basis of models, single frequency off‐resonance decoupling experiments, additivity rules based on benzene substituent effects, and general symmetry considerations.
Reaction of sulfene and dichloroketene with open‐chain N,N‐disubstituted α‐aminomethyleneketones. Synthesis of 4‐dialkylamino‐3,4‐dihydro‐6‐methyl‐5‐phenyl‐1,2‐oxathiin 2,2‐dioxides and of N,N‐disubstituted 4‐amino‐3‐chloro‐(6‐methyl‐5‐phenyl)(6‐benzyl)‐2H‐pyran‐2‐ones
Authors: Bargagna Alberto , Evangelisti Filippo , Schenone Pietro
Published: March 2009

Cycloaddition of sulfene to N,N‐disubstituted 4‐amino‐3‐phenyl‐3‐buten‐2‐ones (III) occurred in good yield only in the case of aliphatic N‐substitution to give 4‐dialkylamino‐3,4‐dihydro‐6‐methyl‐5‐phenyl‐1,2‐oxathiin 2,2‐dioxides, whereas N,N‐disubstituted 4‐amino‐1‐phenyl‐3‐buten‐2‐ones (IV) did not react at all. Polar 1,4‐cycloaddition of dichloroketene to III and IV occurred partly in the case of aromatic N‐substitution, with the exception of the morpholino derivative IVd, giving in low yield N,N‐disubstituted 4‐amino‐3,3‐dichloro‐3,4‐dihydro‐(6‐methyl‐5‐phenyl)(6‐benzyl)‐2H‐pyran‐2‐ones, which were dehydrochlorinated with DBN to the corresponding 4‐amino‐3‐chloro‐(6‐methyl‐5‐phenyl)(6‐benzyl)‐2H‐pyran‐2‐ones (VII) in good yield. In some cases of aliphatic N,N‐disubstitution of III and IV, cycloaddition led directly to N,N‐dialkyl derivatives VII in low yield.
Reactions of 2H‐3,1‐benzoxazine‐2,4‐(1H)dione (isatoic anhydride) with anions of 1,4‐dihydro‐5H‐pyrazol‐5‐ones: Synthesis of pyrazolo[5,1‐b]quinazolin‐9‐ones
Authors: Sircar Jagadish C. , Capiris Thomas , Kesten Stephen J.
Published: March 2009

Reactions of 2H‐3,1‐benzoxazine‐2,4‐(1H)dione (isatoic anhydride) (1) with anions of 1,4‐dihydro‐5H‐pyrazol‐5‐ones (2) gave pyrazolo[5,1‐6]quinazolin‐9‐ones (3) via the nucleophilic attack of the anion 2b rather than 2a. However, in the case of 5‐methoxyisatoic anhydride (10c), both products 3e and 11c were obtained. A new synthetic method of preparation of 5‐(alkylthio)‐2‐aminobenzoic acids (18) was described. These acids (18) were used to synthesize a series of substituted pyrazolo[5,1‐b]quinazolin‐9‐ones (3).
The mixed‐aldehyde synthesis of difunctional tetraarylporphyrins
Authors: Little Robert G.
Published: March 2009

The synthesis is reported of nine unsymmetrical, meso‐substituted porphyrins. Among the compounds prepared are the following 5‐(R)‐10,15,20‐tri‐p‐tolylporphyrins; R = 2,6‐dinitrophenyl, 4‐hydroxy‐3‐ethoxy‐phenyl, 4‐hydroxy‐3‐methoxy‐5‐nitrophenyl, 5‐hydroxy‐2‐nitrophenyl and 4‐hydroxy‐3‐nitrophenyl. Other porphyrins reported include 5‐(2‐(1‐butoxy)phenyl)‐15‐(2‐nitrophenyl)‐10‐15‐di‐p‐tolylporphyrin and the two 5‐(R)‐10‐15,20‐tripropylporphyrins in which R = 2‐nitrophenyl and 2‐hydroxyphenyl. The disubstituted porphyrins offer a rational route to the synthesis of difunctional “tailed‐porphyrins”.
The schmidt reaction on 3a,4,5,6‐tetrahydrosuccinimido[3,4‐b]‐acenaphthen‐10‐one and its alkylated derivatives
Authors: Campaigne E. , Huffman J. C. , Yodice Richard
Published: March 2009

The rearrangement of 3a,4,5,6‐tetrahydrosuccinimido[3,4‐b]acenaphthen‐10‐one and two methylated derivatives using Schmidt conditions is described. The ratio of the major product, 2,3,8,9‐tetrahydro‐3‐oxo‐1H‐benz[de]isoquinoline‐1,9a‐(7H)dicarboximide, to the minor product, 2,3,6,7‐tetrahydro‐3‐oxo‐4H‐benz[ij]‐isoquinoline‐4,4a‐(5H)dicarboximide, under different acidic conditions is given. The ratios of analogous products from the methylated derivatives are similar under similar conditions.
Psilocin analogs II. Synthesis of 3‐[2‐(dialkylamino)ethyl]‐, 3‐[2‐(N‐methyl‐N‐alkylamino)ethyl]‐, and 3‐[2‐(cycloalkylamino)ethyl]indol‐4‐ols
Authors: Repke David B. , Ferguson Wilfred J. , Bates Dallas K.
Published: March 2009

Structural alteration of theNb‐substituents of psilocin (3‐[2‐dimethylamino)ethyl]indol‐4‐ol) (12a) has led to a number of compounds containing known pharmacophoric groups. Further, it is hoped that the subtle changes in the nature of these substituents may lead to a clearer understanding of the structure‐activity relationships of the 4‐hydroxytryptamine hallucinogens.
A practical synthesis of pyoluteorin
Authors: Cue Berkeley W. , Dirlam John P. , Czuba Leonard J. , Windisch Wendell W.
Published: March 2009

A convenient, large‐scale synthesis of the antibiotic pyoluteorin, 2,3‐dichloro‐5‐(2′,6′‐dihydroxybenzoyl)‐pyrrole (1), is described. A key step in the synthesis involved a Friedel‐Crafts aroylation of pyrrole with 2,6‐dimethoxybenzoyl chloride (3) in methylene chloride. The desired intermediate, 2‐(2′,6′‐dimethoxybenzoyl)pyrrole (4), was obtained as the major product, along with a product of beta substitution (6). Compound 4 was converted to pyoluteroin (1) in four steps in an overall yield of 51%.
The preparation of some 1‐(2‐furyl)‐2‐arylethylenes
Authors: Karminski‐Zamola G. , Jakopčić K.
Published: March 2009

Some 1‐(2‐furyl)‐2‐arylethylenes, where the furan nucleus is substituted in position 5 with a methyl or p‐chlorophenyl group and where the aryl group is phenyl, p‐nitrophenyl, α‐naphthyl or β‐naphthyl, have been prepared by the Perkin reaction and subsequent decarboxylation of the acid. The compounds 1‐12 were prepared lor of photochemistry and photoelectron spectroscopy studies. Their geometrical configurations has been established by 1H nmr and ir spectra.
Phase‐transfer catalysis in the N‐benzylation of adenine
Authors: Shinkai I. , Vander Zwan M. C. , Hartner F. W. , Reamer R. A. , Tull R. J. , Weinstock L. M.
Published: March 2009

A convenient phase‐transfer catalysis in the N‐benzylation of adenine is described. The benzylation of adenine with benzyl halides in a two‐phase system containing phase‐transfer catalyst gave 9‐benzylated adenines as a major product accompanied with 3‐benzylated adenines.
Synthesis of 1,2,9,10,17,18‐hexathia[2.2.2](2,6)pyridinophane
Authors: Bottino Francesco , Cosentino Salvatore , Cunsolo Salvatore , Pappalardo Sebastiano
Published: March 2009

The synthesis and spectral properties of the title compound are described.
Oxidative ring‐expansion of benzothiazolines into 1,4‐benzothiazines
Authors: Liso Gaetano , Trapani Giuseppe , Latrofa Andrea , Marchini Paolo
Published: March 2009

By treatment in boiling DMSO, benzothiazolines 1 yield 1,4‐benzothiazines 4 in some cases together with benzothiazoles. Two competing pathways, namely oxidative ring‐expansion and decomposition of benzothiazoline accounting for the formation of 4 and benzothiazoles, respectively, are suggested.
The chemistry of carbazole. VI. On the formation of N‐ethylcarbazoles in the cadogan reaction
Authors: Tsunashima Yutaka , Kuroki Masatane
Published: March 2009

Reaction of 2′,6‐dimethyl‐2‐nitrobiphenyl with triethyl phosphite gave 4,5‐dimethyl‐9‐ethylcarbazole besides 4,5‐dimethylcarbazole. In this reaction, 4,5‐dimethylcarbazole was ethylated by triethyl N‐(2′,6‐dimethybiphenyl‐2‐yl)phosphorimidate and diethyl N‐(2′,6‐dimethylbiphenyl‐2‐yl)phosphoramidate, which arose from a nitrene‐intermediate and triethyl phosphite. Analogous ethylations of carbazole with other phosphorimidate and phosphoramidates were investigated.
Displacement‐cyclization reactions of mono‐substituted hydrazines with chloronitrobenzenes and chloronitropyrimidines. New routes to 8‐azapurine and benzopyrazole derivatives
Authors: Defusco A. A. , Strauss M. J.
Published: March 2009

Reactions of different chloronitrobenzenes and chloronitropyrimidines with monosubstituted hydrazines, R‐NHNH2, where R is methyl, carbomethoxy and phenyl, are described. The reactivity of these hydrazines in displacement‐ortho substituent cyclizations varies substantially, depending on the nature of the aromatic substrate and the hydrazine R group. New routes to 8‐azapurine and benzopyrazole derivatives are decribed.
Structural effects on the acidity of E‐α‐phenyl‐β‐arylacrylic acids
Authors: Maccarone Emanuele , Mamo Antonino , Perrini Giancarlo , Torre Michele
Published: March 2009

The dissociation equilibrium constants of some is‐α‐phenyl‐β‐arylacrylic acids (Ar = 2‐pyridyl, 3‐pyridyl, 4‐pyridyl, 1‐naphthyl, 2‐naphthyl, anthracen‐9‐yl) have been measured in 80% aqueous 2‐methoxyethanol at 25°. The pKa values of these acids, together with those of p‐substituted phenyl, 2‐furyl, 2‐thienyl and selenophen‐2‐yl derivatives, have been rationalized by an equation involving separate contributions of polar, conjugative and steric effects of heterocycles. The pKa values of some E‐α‐phenyl‐β‐alkylacrylic acids (alk = methyl; ethyl; n‐propyl; i‐propyl; n‐butyl; i‐butyl) are also reported.
Stereospecific synthesis of 2,3‐disubstituted 1,4‐benzodioxans
Authors: Proietti Gabriele , Corsano Stefano , Castagnino Enzo
Published: March 2009

The synthesis of cis‐ and trans‐2‐methyl‐3‐phenyl‐1,4‐benzodioxans 4 and 5, from 1‐phenyl‐2‐[2‐(hydroxy)‐phenoxy]propanols threo 2 and erythro 3 are described.
Cyclisation des amides d'acides phénylthio‐1 glyoxaliques avec les dérives carbonylés
Authors: Girault Pierre , Perronnet Jacques
Published: March 2009

Les dérivés carbonylés reagissent sur les amides d'acides phénylthio‐1 glyoxaliques (3) en présence d'iodure de méthyle et provoquent leur cyclisation en dihydro‐2,5 méthylthio‐4 phényl‐5 oxazolols‐5 (4). L'hydroxyle hémiacétalique de ces composés peut ětre méthylé. Si un atome d'hydrogène existe en position 2 (cyclisation effectuée avec un aldéhyde) son élimination conduit à un oxazole, 7.
Formation of flavans in reactions of 4‐hydroxycoumarin with flavylium salts
Authors: Jurd Leonard
Published: March 2009

4′‐Hydroxyflavylium salts react with 4‐hydroxycoumarin to form novel flavan derivatives of type 6.
Coupling to the pyrimido[4,5‐b][1,4]oxazine ring system: Synthesis of potential antifolates
Authors: Winchester Merritt J. , Zappone Lawrence J. , Skinner Charles G.
Published: March 2009

The ability of 2‐amino‐4‐hydroxy‐7H‐pyrimido[4,5‐b][1,4]oxazine derivatives to inhibit dihydrofolate reductase led to a search for means of synthesizing new side chain substituted analogs of this marginally stable pyrimidooxazine system. A study of the synthesis and use of 6‐functionalized pyrimido[4,5‐b][1,4]oxazines for coupling side chains was begun and has now revealed methods for coupling p‐aminobenzoic acid with 2‐amino‐4‐hydroxy‐6‐carboxy‐7H‐pyrimido[4,5‐b][1,4]oxazine and hydrolyzed 2‐amino‐4‐hydroxy‐6‐carbe‐thoxymethylene‐6,7‐dihdyro‐5H‐pyrimido[4,5‐b][1,4]oxazine. The products are of interest for evaluation as potential antifolates.
Regioselective N‐alkylation of 1,2,6‐thiadiazine 1,1‐dioxide derivatives
Authors: Goya P. , Martínez P. , Ochoa C. , Stud M.
Published: March 2009

Reactivity towards alkylating agents in relation to the capacity to bind sodium ions of 1,2,6‐thiadiazine 1,1‐dioxide derivatives is described. The compounds studied are: 1, 4‐nitro‐, 2, 4‐cyano‐, 3,4‐ethoxycarbonyl‐2H,6H‐1,2,6‐thiadiazin‐3‐one 1,1‐dioxide and 4, 3‐amino‐4‐cyano‐6H‐1,2,6‐thiadiazine 1,1‐dioxide. Methylation with dimethyl sulfate of 4‐nitro‐ and 4‐cyanothiadiazines 1 and 2, which show the capacity to bind sodium ions, takes place regioselectively at position 2, whilst the thiadiazines which lack this feature (3 and 4) are methylated at 2 and 6, and 6 respectively. On using diazomethane, in the absence of alkaline ions, no selectivity was observed. Glycosidation reactions of 1, 3 and 4 have also been carried out. The structure of the newly synthesized compounds are discussed on the basis of their analytical and spectroscopic data.
Investigation of intramolecular sulfur‐nitro interactions in 2‐(2′‐pyridylthio)‐3‐nitropyridine by 13C‐NMR spectroscopy and x‐ray crystallography
Authors: Kimura Michio , Simonsen Stanley H. , Caldwell Steven R. , Martin Gary E.
Published: March 2009

The single crystal X‐ray diffraction structure of 2‐(2′‐pyridylthio)‐3‐nitropyridine is reported. A non‐bonded interaction was observed between the sulfur atom and one of the oxygen atoms of the nitro group with an interatomic distance of 2.678 A. Examination of the molecule's behavior in solution by 13C‐nmr spin‐lattice (T1) relaxation measurements showed the non‐nitro bearing pyridyl ring to reorient anisotropically about the C2′‐C5′ bond axis. In contrast, the nitro substituted pyridine ring did not appear to exhibit anisotropic reorientation about the corresponding C2‐C5 bond axis. Rather, approximately equivalent relaxation times were noted for all protonated ring carbons, indicating that the relaxations of this portion of the molecule were governed by the overall isotropic reorientation of the system. Based on these observations, it was concluded that the intramolecular sulfur‐nitro interaction also operates in the solution state and is sufficiently strong to prevent free rotation of the substituted portion of the molecule about the C2‐S bond axis.
A novel synthesis of 4,6‐dimethyl‐ and diphenyl‐2,5‐dihydro‐1,3,5,2‐triazaphosphorines
Authors: Li Ven‐Shun , Cates Lindley A.
Published: March 2009

The synthesis of 2,5‐dihydro‐1,3,5,2‐triazaphosphorines via the intramolecular cyclization of N,N'‐phos‐phinylacetamidines or benzamidines is described. These derivatives represent the sole examples of 4,6‐dialkyl or diaryl substitutions of this ring system.
Structure et synthèses nouvelles dans la série des amino‐4 dihydro‐5,6 méthyl‐6 pyrones‐2
Authors: Nedjar‐Kolli Bellara , Hamdi Maamar , Périé Jacques , Hérault Valentin
Published: March 2009

L'étude de l'action des amines primaires et secondaires sur les dihydro‐5,6, hydroxy‐4 pyrones‐2 a tout d'abord permis de corriger un résultat antérieur: l'attaque du nucléophile a lieu sur l'atome de carbone en 4, et non sur celui en position 2, trop peu électrophile. Une nouvelle famille de composés dont certains ont des propriétés pharmacologiques intéressantes est ainsi développée. Par ailleurs les réactivités des dihydro‐5,6 pyrones et celles des pyrones parentes sont comparées.
Syntheses of some 2‐hydroxypyrazine 1‐oxides
Authors: Ohta Akihiro , Masano Sawako , Tsutsui Mayumi , Yamamoto Fusako , Suzuki Sumie , Makita Hiromi , Tamamura Hideo , Akita Yasuo
Published: March 2009

A series of 2‐hydroxypyrazine 1‐oxides were prepared from the corresponding chloropyrazines by two methods, including oxidation processes in satisfactory yields. The treatment of 2,3‐diphenylpyrazine 1,4‐dioxide (6) led to 2,3‐dichloro‐5,6‐diphenylpyrazine (7) and 2‐chloro‐5,6‐diphenylpyrazine 1‐oxide (8), and the latter was converted to 5,6‐diphenyl‐2‐hydroxypyrazine 1‐oxide (9) by an alkaline hydrolysis.
Synthesis of methylpyridine derivatives. XXXV. Reaction of acetylpyridine with phosphoryl chloride to give alkynylpyridine
Authors: Kato Tetsuzo , Sato Masayuki , Wagai Akihiro
Published: March 2009

Reaction of 3‐acetyl‐4,6‐dimethyl‐2‐(1H)pyridone (9a) with phosphoryl chloride gives 2‐chloro‐3‐ethynyl‐4,6‐dimethylpyridine (10a). 3‐Acetyl‐4‐hydroxy‐6‐methyl‐2(1H)pyridone (14a) and 3‐acetyl‐2,6‐dimethyl‐4‐(1H)‐pyridone (21) undergoes similar reaction to give the corresponding ethynyl (16 and 23) and chlorovinyl (15 and 22) pyridines, respectively. The chlorination of 3‐acetylpyridine and pyrimidine derivatives is further described.
Mannich reaction on 2‐(2‐benzofuranyl)‐1H‐indole. Determination of structure by NMR spectroscopic techniques
Authors: Badger E. , Dicataldo S. , Kahle A. D. , Nadelson J. , Shapiro M. J.
Published: March 2009

Analysis of the product from the Mannich reaction of 2‐(2‐benzofuranyl)‐1H‐indole via 1H and 13C nmr spectroscopy was performed. The studies included use of Pr(Fod)3 shift reagent, proton‐coupled 13C spectra, deuterium isotope induced shifts and protonation studies. It was found that the reaction occurred on the indole moiety at C‐3.
1,2,4‐triazines. 1. A convenient synthesis of 4,5‐dihydro‐1,2,4‐triazin‐3‐(2H)one and its 6‐substituted derivatives
Authors: Nakayama Yoshinori , Sanemitsu Yuzuru , Mizutani Masato , Yoshioka Hirosuke
Published: March 2009

A facile synthesis of 4,5‐dihydro‐1,2,4‐triazin‐3‐(2H)one (2a) from 5‐methylthio‐1,2,4‐triazin‐3‐(2H)one (1a) with sodium borohydride is described. The reaction provides a convenient method for its 6‐substituted derivatives (2b‐h).
Synthesis of 2,3‐disubstituted‐4‐oxothiazolidine 1‐oxides
Authors: Omar M. T. , El‐Khamry A. E. , Sherif F. A.
Published: March 2009

The reaction of chloramine‐T with 2,3‐disubstituted‐4‐oxothiazolidines 1a‐c give the corresponding sulfoxides 2a‐c, whose structures were based on analytical and spectral data.
The photochemical synthesis of 4‐acyl‐1,2‐dimethyl‐3H‐phenothiazin‐3‐ones
Authors: Ueno Yoshio , Takeuchi Yutaka , Koshitani Jinya , Yoshida Takatoshi
Published: March 2009

4‐Acyl‐1,2‐dimethyl‐3H‐phenothiazin‐3‐ones were prepared by the photochemical reaction of 1,2‐dimethyl‐3H‐phenothiazin‐3‐one with aldehydes. The structures of the newly prepared compounds were determined by elemental analysis, spectroscopic methods (ir, nmr and ms) and comparison with a sample prepared by an alternate route.
Preparation of 2,4‐diarylquinolines and substituted dihydrobenz‐[c]acridines by the condensation of certain c(α),o‐dilithiooximes with 2‐aminobenzophenones
Authors: Park Dorothy J. , Fulmer Tammy D. , Beam Charles F.
Published: March 2009

C(α),O‐Dilithiooximes were prepared in an excess of lithium diisopropylamide and condensed with several 2‐aminobenzophenones, followed by acid hydrolysis of the oximes to the ketones, which then underwent cyclodehydration and linear dehydration to give substituted quinolines or dihydrobenz[c]acridines.
The synthesis of proximal‐benzolumazine, proxirnal‐benzoxanthine, proximal‐benzotheophylline and proximal‐benzocaffeine
Authors: Schneller Stewart W. , Christ William J.
Published: March 2009

The synthesis of pyrazino[2,3‐f]quinazolin‐8,10‐(7H,9H)dione(proximal‐benzolumazine, 1), imidazo[4,5‐f]‐quinazolin‐7,9‐(6H,8H)‐dione (proximal‐benzoxanthine, 2), 6,8‐dimethylimidazo[4,5‐f]‐quinazolin‐7,9‐(6H,8H) dione (proximal‐benzotheophylline, 3), and 1,6,8‐trimethylimidazo[4,5‐f]quinazolin‐7,9‐(6H,8H)dione (proximal‐benzocaffeine, 4) is reported by commencing with 2‐amino‐6‐chlorobenzamide and proceeding via a variety of 5,6‐disubstituted‐2,4‐(1H,3H)quinazolinediones. Methylation of 3 is shown to yield 3,6,8‐trimethylimidazo[4,5‐f]quinazolin‐7,9‐(6H,8H)dione (15) and 4 in a ratio of 4:1.
Imidazo[1,2‐α]pyridine anthelmintics. Synthesis of 6‐phenylaminoimidazo[1,2‐α]pyridine‐2‐carbamate and 5‐acylaminopyridines by a chapman rearrangement
Authors: Peterson L. H. , Douglas A. W. , Tolman R. L.
Published: March 2009

The title compound, a potential anthelmintic agent, was prepared in seven steps from 5‐hydroxy‐2‐picoline. The intermediate 5‐(N,‐phenylbenzamido)‐2‐picoline was prepared by a facile Chapman rearrangement of the corresponding benzimidoyl ester. Oxidation and Curtius rearrangement of the substituted picoline gave 5‐(N‐phenylbenzamido)‐2‐aminopyridine which underwent ring closure and debenzoylation to furnish methyl 6‐phenylaminoimidazo[1,2‐α]pyridine‐2‐carbamate. Fries rearrangement of the penultimate N‐benzoyl derivative gave a 6‐(p‐benzoylphenylamino)imidazo[1,2‐α]pyridine derivative, whose structure was confirmed by cmr study. The title compound lacked significant anthelmintic activity.
Pyoluteorin derivatives. II. Synthetic approaches to pyrrole ring substituted pyoluteorins
Authors: Cue Berkeley W. , Chamberlain Nancy
Published: March 2009

A method for the regiospecific synthesis of 3‐substituted 2‐aroylpyrroles is described. These pyrroles, which are structurally related to the naturally occurring antibiotic pyoluteorin, are prepared by a Friedel‐Crafts aroylation of 4‐substituted pyrrole‐3‐carboxylic acid esters with 2,6‐dimethoxybenzoyl chloride. The carboalkoxy group is then removed by hydrolysis and decarboxylation to produce isomerically pure 3‐substituted‐2‐(2′,6′‐dimethoxybenzoyl)pyrroles (5 and 13). Conversion of these pyrroles into pyoluteorin‐like compounds led to some unexpected products which arise from facile cleavage of the dihydroxybenzoyl portion of the molecules during chlorination.
Synthesis of [9][3,6]‐s‐tetrazinophane
Authors: Beccalli Egle M. , Puppo Marina Del , Licandro Emanuela , Marchesini Alessandro
Published: March 2009

The first synthesis of a tetrazinophane, from 2‐nitrosocyclodecane‐1,3‐dione, is reported.
The thiomethylation of substituted glutarimides
Authors: Seitz David E. , Needham Fang‐Ling
Published: March 2009

Conditions for the mono‐ and di(thiomethylation) of N‐methyl‐3‐ethyl‐3‐phenylpiperidine‐2,6‐dione and the monothiomethylation of N‐methyl‐3‐(4‐aminophenyl)‐3‐ethylpiperidine‐2,6‐dione, potential inhibitors of estrogen synthetase, are described and contrasted with a closely related lactam, N‐methylpiperidone. The influence of solvent, base and electrophile on product distribution is explored.
Synthesis of 4,10‐dihydro‐4,10‐dioxo‐1H‐[1]‐benzopyrano[3,2‐b]pyridine, 4,5‐Dihydro‐4,5‐dioxo‐1H‐[1]‐benzopyrano[2,3–6]pyridine and 1,5‐Dihydro‐1,5‐dioxo‐4H‐[1]‐benzopyrano[3,4‐b]pyridine derivatives from aminobenzopyrones
Authors: Connor David T. , Young Patricia A. , Von Strandtmann Maximilian
Published: March 2009

3‐Aminochromone and 3‐aminocoumarin were condensed with diethyl ethoxymethylenemalonate and with dimethyl acetylenedicarboxylate to give intermediates, which were thermally cyclized to give 4,10‐dihydro‐4,10‐dioxo‐lH‐[1]‐benzopyrano[3,2‐b]pyridinecarboxylates and 1,5‐dihydro‐1,5‐dioxo‐4H‐[1]‐benzopyrano‐[3,4‐b]pyridinecarboxylates. 2‐Aminochromone was converted to 4,5‐dihydro‐4,5‐dioxo‐1H‐[1]‐benzopyrano‐[2,3‐b]pyridinecarboxylate via an intermediate condensation product with diethyl ethoxymethylenemalonate. These esters were hydrolyzed to the corresponding carboxylic acids (21, 30, 36, 50, and 60). Attempts to prepare 4,5‐dihydro‐4,5‐dioxo‐1H‐[1]‐benzopyrano[4,3‐b]pyridinecarboxylates from 4‐aminocoumarin were unsuccessful.
The chemistry of carbazoles. VII. Syntheses of methylcarbazoles
Authors: Kuroki Masatane , Tsunashima Yutaka
Published: March 2009

Thirty‐six methylcarbazoles were prepared, and their synthetic methods were critically described.
Nouvelles voies d'accès à des aryl‐4 thiéno[2,3‐c]pyridines et à des aryl‐7 thiéno[3,2‐c]pyridines
Authors: Maffrand Jean‐Pierre , Boigegrain Robert , Courregelongue Jean , Ferrand Gerard , Frehel Daniel
Published: March 2009

Des aryl‐4 thiéno[2,3‐c]pyridines et des aryl‐7 thiéno[3,2‐c]pyridines ont été respectivement obtenues par chauffage dans l'acide polyphosphorique de [thényl‐2 amino]‐2 aryl‐1 éthanols ou propanols et de [thényl‐3 amino]‐2 aryl‐1 éthanols ou propanols. La transposition de Beckmann d'oximes d'aryl‐4 dihydro‐4,5 6H‐cyclopenta[b]thiophènone‐6, conduit à des aryl‐4 dihydro‐4,5 6H‐thiéno[2,3‐c]pyridones‐7.
Pyrrolo[1,2‐a]thieno[3,2‐e]pyrazines
Authors: Rault Sylvain , De Sévricourt Michel Cugnon , Dung Nguyen‐Huy , Robba Max
Published: March 2009

La dihydro‐4,5 oxo‐5 pyrrolo[1,2‐a]thiéno[3,2]pyrazine 6 et ses dérivés sont accessibles par cyclisation intramoléculaire de l'azoture de (pyrrolyl‐1)‐2 thénoyle‐3 2. La synthèse de la pyrrolo[1,2‐a]thiéno[3,2‐e]pyrazine 10 est réalisable soit par déshydrazination du dérivé 14 soit à partir de la (pyrrolyl‐1)‐2 thiénylamine‐3 4. Les spectres de rmn sont étudiés.
1H‐imidazo[4,5‐b]pyrazines. III. 2‐Thiols and derivatives
Authors: Tong Y. C.
Published: March 2009

1H‐Imidazo[4,5‐b]pyrazine‐2‐thiols were prepared. Their chlorination, alkylation and cyclization reactions are discussed.
Reissert compound studies. XLI. Synthesis and reactions of the pyrrolo[1,2‐α]quinoxaline reissert compound and its analogs
Authors: Veeraraghavan S. , Popp F. D.
Published: March 2009

Reaction of pyrrolo[1,2‐α]quinoxaline, either by the phase‐transfer catalyst method or by the trimethylsilyl cyanide method, yielded the Reissert compound, 5‐benzoyl‐4‐cyano‐4,5‐dihydropyrrolo[1,2‐α]quinoxaline. This Reissert compound rearranged to 4‐benzoylpyrrolo[1,2‐α]quinoxaline upon sodium hydride treatment. It also underwent methylation with methyl iodide and sodium hydride. A few Reissert analogs of the pyrroloquinoxaline were also prepared and their reactions studied.
Synthesis of 5H‐benzothiazolo[3,2‐a]quinazolin‐5‐ones
Authors: Kim Dong Han
Published: March 2009

5H‐Benzothiazolo[3,2‐a]quinazolin‐5‐ones (Va‐d) were synthesized by thermal cyclization of N‐(2‐benzothiazolyl)‐2‐fluorobenzamides (IVa‐d) which were obtained by allowing 2‐fluorobenzoyl chloride to react with 2‐aminobenzothiazoles.
Synthesis of some imidazole‐ and pyrazole‐ derived chelating agents
Authors: Addison Anthony W. , Burke Philip J.
Published: March 2009

Procedures involving condensation of o‐phenylenediamines with carboxylic acids, and reaction of bifunctional alkyl halides with bifunctional nucleophiles are described. Syntheses are reported of 2,6‐bis‐(2‐benzimidazyl)‐pyridine, 1,3‐bis(2‐benzimidazyl)‐2‐thiapropane, 1,7‐bis(2‐benzimidazyl)‐2,6‐dithiaheptane, 2‐hydroxymethyl‐5,6‐dimethylbenzimidazole, 2‐chloromethyl‐5,6‐dimethylbenzimidazole hydrochloride, 1,7‐bis(5,6‐dimethyl‐2‐benzimidazyl)‐2,6‐dithiaheptane, 3,6‐bis(1‐pyrazolyl)pyridazine, 2‐(2‐hydroxy‐3‐methyl–phenyl)benzimidazole, 2‐(2‐hydroxyphenyl)benzimidazole, 5‐(2‐hydroxphenyl)‐3‐methyl‐1‐phenylpyrazole, 3(5)‐(2‐hydroxyphenyl)‐5(3)‐methylpyrazole, 3(5)‐(2‐hydroxyphenyl)‐5(3)‐phenylpyrazole, and 1,3‐bis((5‐methylpyridyl)imino)isoindoline.
Novel tetracyclic spiropiperidines. II. Synthesis of 2‐aryl‐2,3‐dihydrospiro[benzofuran‐3,4′‐piperidines]
Authors: Ong Helen H. , Agnew Marc N.
Published: March 2009

A series of 2‐aryl‐2,3‐dihydropsiro[benzofuran‐3,4′‐piperidines] has been synthesized as potential psychotropic agentsviaan efficient intramolecular fluorine displacement reaction. Treatment of a key intermediate, 4‐cyano‐4‐(2‐fluorophenyl)‐1‐methylpiperidine (2), with a large excess of phenylmagnesium bromide in refluxing tetrahydrofuran led to some 2‐arylspiro[3H‐indole‐3,4′‐piperidine] derivatives,10and11, whose structures are elucidated on the basis of chemical and spectral evidence.