bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractTreatment 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

AbstractThe 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

Abstract1‐Benzyloxy‐1,2,3‐benzotriazole was photolyzed and found to yield benzaldehyde and azobenzene as the principal products.
A new mesoionic species in the synthesis of some 5‐thioxo‐1,2,4‐triazolin‐3‐ones
Authors: Ziman S. D. 
Published: March 2009

AbstractIn 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

AbstractLors 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

AbstractSynthesis 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.
Préparation de cétals cycliques à plus de sept chaǐnons
Authors: Einhorn Jacques , Bacquet Cathy , Lelandais Daniel 
Published: March 2009

AbstractNous 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

AbstractThe 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

AbstractSeveral 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

AbstractSeveral 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

AbstractReaktionen 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

AbstractAlthough 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

AbstractThe 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

AbstractReduction 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

Abstract5‐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

AbstractEthyl 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

AbstractThe 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

AbstractA 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

Abstractβ‐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

Abstract1,2,3‐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

AbstractReaction 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

AbstractEs 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

Abstract1‐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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

Abstract2‐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

AbstractThe 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

AbstractThe 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

AbstractDie 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

Abstract5,6,7,8‐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

AbstractEvidence 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

AbstractTreatment 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

AbstractThe 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

AbstractThe 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

AbstractCycloaddition 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

AbstractReactions 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

AbstractThe 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

AbstractThe 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.