bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pyrimidine derivatives and related compounds VI. A novel synthesis of 3,5‐diacetamidopyrazole and of 2‐aminopyrazolo [1,5‐α] pyrimidines
Authors: Fanagdi Mohamed Hilmy , Kandeel Ezzat Mohamed , Zayed Ezzat Mohamed , Kandil Zaghtoul Flshahat 
Published: April 2009

Abstract3,5‐Diaeetamidopyrazole (2) could be prepared via arylazo group decoupling from 3,5‐diamino‐4‐arylazopyrazoles (1a‐c) by the action of acetic acid‐sulfuric acid mixture. Arylazo group removal could also be effected when 2‐amino‐5‐melhyl‐7‐oxo‐6,7‐dihydro‐3‐phenylazopyrazolo‐[1,5‐α]pyrimidine (5) was similarly treated. The 2‐aminopyrazolo[1,5‐α]pyrimridine derivative was obtained in this case. On the other hand, under the same experimental conditions compounds 7a‐c and 8 were recovered almost unaffected. The mechanism of the reaction is discussed.
Diazepines II. A new synthesis of 4h‐pyrrolo[ 1,2‐α] ‐[1,41] benzodiazepine
Authors: Kayama Yasutaka , Hara Takeshi , Itoh Kazuhiko , Sunami Tamiko 
Published: April 2009

AbstractA convenient synthesis of a 4H‐pyrroIo[1,2‐α][1,4 ]benzodiazepine is described. 2,5‐Di‐methoxy‐2‐melhyl‐5‐phthalimidomethyltetrahydrofuran (3) was prepared starting from 2‐methyl‐5‐phthalimidomelhylfuran (1). The condensation of 2‐amino‐5‐chlorobenzophcnone with 3 to give 5‐chloro‐2‐(2‐methyl‐5‐phthalimidomethylpyrro]‐1‐yl)benzophenone (4), the treatment of which with hydrazine hydrate afforded 8‐chloro‐1‐methyl‐4H‐pyrrolo[1,2‐α] [1,4]benzodiazepine (5).
β‐substitution of simple pyrroles in metal‐assisted reactions with kthyl diazoacetate
Authors: Maryanoff Bruce E. 
Published: April 2009

AbstractThe reaction of N‐methylpyrrole with ethyl diazoaeelate, assisted by copper bronze or copper powder, as described previously by a number of researchers, produces not only ethyl N‐melhylpyrrole‐2‐acetate (3), but also heretofore unrecognized ethyl N‐melhylpyrrole‐3‐acetate (4); the ratio of 3/4 was ca. 84/16. Promotion of this reaction with other transition metal catalysts furnished differing proportions of 3 and 4, indicating that the metal is intimately involved in the substitution process. Certain agents, notably cupric fluoborate, cupric trifluoromelhylsullonate, palladous acetate, and (π‐C3H5 PdCI)2, were particularly active in this reaction and gave β‐substi‐lulion to the extent of ca. 35‐45%. Other pyrrole compounds, namely 1,2‐dimethylpyrrole, 1,3‐dimethylpyrrole, 3, and pyrrole, were also found (in preliminary work) to undergo β‐substi‐tution in their reaction with copper carbenoids.
A comparison of two methods for the preparation of 3‐Deazapurine ribonucleosides
Authors: Montgomery John A. , Shortnacy Anita T. , Clayton Sarah D. 
Published: April 2009

AbstractThe reaction of the trimethylsilyl derivative of 4,6‐dichloroimidazo[4,5‐c]pyridine with 2,3,5‐tri‐O‐benzoyl‐D‐ribofuranosyl bromide gave four nucleosides‐the α‐ and β‐anomers of the 1‐isomer and the α‐ and β‐anomers of the 3‐isomer (3.9:2.7:1.5:1). In contrast, the fusion reaction of 4,6‐dichloroimidazo[4,5‐c ]pyridine with 1,2,3,5‐tetra‐O‐acetyl‐β‐D‐ribofuranose gave a high yield of the 1‐β‐isomer, which was converted to the known 3‐deazaadenosine (4‐amino‐l‐β‐D‐ribofuranosylimidazo[4,5‐c]pyridine).
Ion radicals. 40. Formation of 10‐phenylphenothiazine 5‐oxide and Nitro‐10‐phenylphenolhiazirie 5‐oxides by reaction of 10‐phenylphcnolhiazine cation radical perchlorate with nitrite ion
Authors: Bandlish Baldev K. , Kim Kyongtae , Shine Henry J. 
Published: April 2009

AbstractThe reaction of 10‐phenylphenolhiazine cation radical (1) with nitrite ion leads not only to 10‐phenylphenothiazine 5‐oxide (2) but also to 3‐nitro‐10‐phenylphenothiazinc 5,5‐dioxide (4), and two dinitro‐10‐phenylphenolhia/.ine 5‐oxidcs (5 and 6). The products (3‐6) appear to he formed from the nitration of 2 by nitrogen dioxide, the nitrogen dioxide arising from the reaction of nitric oxide (formed along with 2 when 1 reacts with nitrite anion) and oxygen.
N‐trimethylsilylpyrroles as dienes in the synthesis of 1,4‐dihydronaphthalen‐1,4‐imines and isoindoles
Authors: Anderson P. S. , Christy M. E. , Engelhardt E. L. , Lundell G. F. , Ponticello C. S. 
Published: April 2009

AbstractA convenient, general synthetic method for 1,4‐dihydronaphthaIen‐1,4‐imines via the Diels‐Alder addition of benzyne to N‐trimethylsilylpyrrole is described. The N‐trimethylsilyl protecting group protected the product from secondary benzyne reactions and was easily removed. The use of a 1,3‐dipolar reagent to convert 1,4‐dihydronaphthalen‐1,4‐imines to isoindoles via a retro‐Diels‐Alder sequence is illustrated.
Reactions with heterocyclic diazonium salts: New routes for the synthesis of pyrazolo[1,5‐c]‐1,2,4‐triazoles and pyrazolo[1,5‐c]‐as‐triazines
Authors: Elnagdi Mohamed Hilmy , Elmoghayar Mohamed Riffat Hamza , Kandeel Ezzat Mohamed , Ibrahim Mohamed Kamal Ahmed 
Published: April 2009

Abstract3‐Phenylpyrazole‐5‐(liazonium chloride (1) couples with α‐chloro derivatives of acetylacetone, ethyl acetoacetate and aceto‐o‐anisidine to yield the corresponding pyrazole‐5‐yl hydrazonyl chloride derivatives 2a‐c. Compounds 2a,b were cyclised to yield either the pyrazolo[1,5‐c]‐1,2,4‐triazole derivatives 3a,b or the pyrazolo[1,5‐c]‐as‐triazines 4a,b depending on the applied reaction conditions. Compound 2c cyclised only into 3c under different cyclization conditions. The pyrazolo[1,5‐c]‐as‐triazine derivatives 4c‐e could be prepared via condensation of 2a with potassium cyanide. Compound 2d reacted with aromatic thioles and with sodium benzene‐sulphonate to yield the pyrazolo[1,5‐c]‐as‐triazine derivatives 6a‐d. Compound 1 reacted with activated double bond systems to yield pyrazolo[1,5‐c]‐as‐triazines 8a,b and 9.
Mass spectral fragmentation pattern of 2,2′‐bipyridyls. Part VII 2,2′‐dithiodipyridine
Authors: Keats N. G. , Summers L. A. 
Published: April 2009

AbstractThe mass spectral fragmentation of 2,2′ ‐dithiodipyridine involves loss of the elements S, SH and S2 from the molecular ion in addition to rupture of the central bonds. Molecular rearrangements accompany the disintegration.
The reaction of 2‐acetoacetamidopyridines with phosgene. A route to novel 3‐Acetyl‐2‐chloro‐4H‐pyrido[ 1,2‐a] pyrimidin‐4‐ones
Authors: Yale Harry L. , Spitzmiller E. R. 
Published: April 2009

Abstract2‐(Acetoacetamido)pyridine, 1, and its 5‐methyl derivative, 2, with phosgene, gave 3‐acetyl‐2‐chloro‐4H‐pyrido[1,2‐a]pyrimidin‐4‐one, 5, and 3‐acetyl‐2‐chloro‐7‐methyl‐4H‐pyrido[1,2‐a]‐pyrimidin‐4‐one, 6, respectively. The structures of these compounds followed from their elemental analyses, and interpretations of their uv, ir, pmr, and X‐ray spectra. An alternative route to 5 and 6, which sought first to react 1 and 2 with methyl ‐ and benzyl chloroformates, was unsuccessful, and led, instead, to elimination of the acetoacetyl group with concomitant formation of the carbamate derivatives, 10 and 11.
Thermal 1,3‐aroyl migration in 1 (α‐aroyloxyarylideneamino) −1,2,3‐triazoles
Authors: Alexandrou N. E. , Hadjiantoniou C. P. 
Published: April 2009

AbstractKinetic studies on the thermal rearrangement of the 1‐(α‐aroyloxyarylideneamino)‐4,5‐di‐methyl‐1,2,3‐triazoles (II) to the corresponding diaroylimides (III) have shown that the 1,3‐aroyl migration from oxygen to nitrogen proceeds in a concerted way and the isomerization reaction can be described as an [1,3] sigmatropic aroyl shift.
Attack of S‐ vs N‐Nucleophiles on 2‐halomethylquinazoline 3‐Oxides
Authors: Broadbent H. Smith , Anderson Richard C. , Kuchar Marvin C. J. 
Published: April 2009

AbstractA comparison is made of thiols with amines in their mode of reaction with different substituted 2‐halomethylquinazoline 3‐oxides. Whereas the reaction of some amines (particularly small primary ones), as has long been known, leads to ring‐enlarging rearrangement under certain conditions, all thiol nucleophiles we have observed, ranging from small to large, lead without rearrangement to direct benzylic substitution only. Preformed aminomethylquinazoline 3‐oxides are shown not to rearrange to the corresponding 1,4‐benzodiazepine 4‐oxides. The mechanistic implications of these and other observations are discussed. Data on over forty new compounds are presented.
Chemistry of thienopyridines. XXV. Comparative mass spectra of some amino and acylamino derivatives
Authors: Klemm L. H. , Barnish I. T. , Mccoy D. R. 
Published: April 2009

AbstractElectron‐impact mass spectral fragmentation patterns are reported for various aminothieno‐pyridines (TPNH2) and aeylaminothtenopyridines. The molecular ion TPNH2+ shows loss of atomic hydrogen, hydrogen cyanide and both thioformyl radical and cation. TPNH2+ is the most abundant ion in the spectrum of each acylamino compound investigated. A semiquanti‐tative mass spectrum of the amine TPNH2 can be obtained by deletion of selected peaks (for the acetylium and molecular ions) from the observed mass spectrum of the A‐acetyl derivative.
New synthesis of octahydro‐2‐methyl‐2H‐pyrazino[1,2‐a]pyrazine
Authors: Beim Howard J. , Day Allan R. 
Published: April 2009

AbstractA new method has been developed for the synthesis of octahydro‐2‐methyl‐2H‐pyrazino‐[1,2‐a]pyrazine. 2‐Benzylaminoethanol was the starting material.
A general synthesis of 2,5‐diaryl‐4‐chloro (or bromo)oxazoles
Authors: Davis Michael , Lakhan Ram , Ternai Bela 
Published: April 2009

AbstractReaction between acyleyanides (ArCOCN) and aldehydes (ArCHO) in the presence of ether and hydrogen chloride (or hydrogen bromide) gives good yields of 2,5‐diaryl‐4‐chloro (or bromo)oxazoles (2).
Structural reassignment of the dehydration product of 2′‐Hydroxywarfarin
Authors: Porter William H. , Trager William F. 
Published: April 2009

AbstractThe base catalyzed condensation reaction between 4‐hydroxycoumarin and o‐hydroxybenzal‐acetone yields 6‐methyl‐6,12‐methano‐6H,12H,13H‐[1]benzopyran[4,3‐d][1,3]benzodioxocin‐13‐one as the product rather than 6‐oxo‐7‐(2‐oxopropyl)‐6H, 7H‐[1]benzopyrano[4,3‐b][1]‐benzopyran as had been previously postulated.
Reactions of nitrenes with strained olefins. Nitrene additions to the bicyclo[2.2.1]hept‐2‐ene system
Authors: Meyer C. Richard , Rao Nancy A. 
Published: April 2009

AbstractThe synthesis of two examples of the 3‐azatricyclo[3.2.1.02,4] octane ring system is described. The product azabicycles are obtained in low yields and are stable in refluxing chlorobenzene. The lead tetraacetate oxidation of 3‐amino‐2‐methvl‐4‐quinazoIone leads to high yields of the deaminated compound.
Some reactions of 1,3,5‐Triaza‐7‐phosphaadamantane and its 7‐Oxide
Authors: Siele V. I. 
Published: April 2009

AbstractThe synthesis of 1,3,5,7‐triazaphosphocine and 1,3,7‐triaza‐5‐phosphabicyclo[3.3.1]nonane derivatives via nitration, nitrosation and acetylation of 1,3,5‐triaza‐7‐phosphaadamantane and its 7‐oxide is reported. A comparison of the reactions of the triazaphosphaadamantane with the analogous reactions of hexamine is made.
Intramolecular nucleophilic cyclization of a carboxylic acid hydrazide under mild acid conditions
Authors: Martin Gary E. , Munson James W. 
Published: April 2009

AbstractPhthaloyl‐2′‐nitrophenylhydrazide undergoes ring closure involving nucleophilic attack of the hydrazide on the carboxylic acid in dilute aqueous acid solution to form the corresponding N‐substituted phthalimide. Structure of the resulting phthalimide was unequivocally confirmed by 13C‐nmr.
Dye‐sensitized photooxidation of chlorpromazine
Authors: Rosenthal I. , Bercovici T. , Frimer A. 
Published: April 2009

AbstractChlorpromazine efficently quenches singlet oxygen (1O2) with a kq= 3.5 × 107M−1s−1.The major result of the chemical interaction between these two species is the cleavage of theN‐side chain.
Identification of the addition products formed in the chlorination of benzofuran
Authors: Baciocchi Enrico , Clementi Sergio , Sebastiani Giovanni V. 
Published: April 2009

AbstractThe cis and trans isomers of 2,3‐dichloro‐2,3‐dihydrohenzofuran have been prepared and their reactions studied in the presence and in the absence of bases. Some data on the influence of the experimental conditions on the stereochemical course of the reaction are also reported.
Synthesis and tautomeric structure of some 2H‐pyrazolo[3,4‐d]pyridazines
Authors: Shawali Ahmad Sami 
Published: April 2009

AbstractA number of substituted 2H‐pyrazolo[3,4‐d]pyridazines, pyridazin‐7(6H)ones, and ‐pyrid‐azine‐4,7(5H,6H)diones have been prepared from the 3,4‐diacyl‐, 3‐carbethoxy‐4‐acyl‐, 3‐carbethoxy‐4‐cyano‐, and 3,4‐dicarbethoxy‐pyrazole derivatives and hydrazine hydrate. The structures of the compounds prepared were inferred from their elemental analyses and spectral data. On the basis of spectroscopic data it was concluded that pyrazolopyridazinones have the oxo form, whereas the monohydroxymono oxo structure is preferred for pyrazolopyridazine‐diones.
The mass spectrometric fragmentation patterns of some biologically active 1,3,4‐thiadiazoles
Authors: Kirkien‐Rzeszotarski Alicja M. , Rzeszotarski W. J. 
Published: April 2009

AbstractMass spectra of some twelve derivatives of 1,3,4‐thiadiazole are reported. The fragmentation scheme of the 1,3,4‐thiadiazole ring is specific and indicative as to the structure. Derivatives of 5‐phenyl‐1,3,4‐thiadiazoles show rearrangement to isothiocyanates.
Analogs of sparteine. IV. Mass spectral features of a series of N, N′‐disubstituted bispidines
Authors: Ruenitz Peter C. , Smissman Edward E. , Wright Deborah S. 
Published: April 2009

AbstractThe mass spectra of a series of N, N′‐disubstituted bispidinc derivatives have been investigated, and salient features analogous to those seen in the spectra of related azabieyelie compounds observed. The most important feature observed in the spectra is the common base peak (m/e 58), which results from the generation of N, N‐dimethylformimmonium ion 24. The pathway by which this ion originates is discussed.
Oxidation reactions of 3,4,5‐triamino‐1,2,6‐thiadiazine 1,1‐dioxide. Preparation of 3,5‐diamino‐4H‐1,2,6‐thiadiazin‐4‐one 1,1‐dioxide
Authors: Garcia‐Muñoz G. , Ochoa C. , Stud M. 
Published: April 2009

AbstractOxidation reactions of 3,4,5‐triamino‐1,2,6‐thiadiazine 1,1‐dioxidc with hydrogen peroxide and chromium trioxide are reported. 3, 5‐Diamino‐4H‐1,2,G‐thiadiazin‐4‐one 1,1‐dioxide is synthesized by different methods.
Anionotropic shift of the 3‐substituent in the reaction of 2‐methoxy‐2,3‐dihydro‐3‐benzofuranols with boron trifluoride
Authors: Caranti Luisa , Zecchi Gaetano , Pagnoni Ugo M. 
Published: April 2009

AbstractThe reaction of 2,3‐dihydro‐3‐benzofuranols 1a,c,d,f with boron trifluoride in boiling xylene gave 3‐(2H)benzofuranones 2a,c,d,f in 40‐85% yield. This reaction was not observed in the case of 1b,e.
Réactivité de l'hypochlorite de tertiobutyle dans l'oxydation du benzothiophene
Authors: Ceneste P. , Olivé J. L. , Ung S. N. 
Published: April 2009

AbstractDans la réaction avec le benzothiophéne, l'hypochlorite de tertiobulyle se comporte á la fois comme réactif d'oxydation et réaetif de chloration. On obtient un mélange de chloro‐3 benzothiophéne, de trois sulfoxydes isoméres du dichloro‐2,3 dihydro‐2,3 benzothiophéne (trans‐anti; trans‐syn; cis‐anti) et de sulfoxyde du chloro‐2 benzothiophéne. Avec un excés important d'hypochlorite, la réaction conduit au dichloro‐2,3 benzothiophene etaux sulfoxydes du dichloro‐2,3 benzothiophéne, du trichloro‐2,2,3 dihydro‐2,3 benzothiophéne et du dichloro‐2,2 oxo‐3 benzothiophéne. L'oxydation s'arrěte toujours au stade du sulfoxyde.
Synthése par deux voies différentes d'un systéme dihétérocyclique apparenté aux peltogynoides
Authors: Deschamps‐Vallet Colette , Meyer‐Dayan Michéle , Andrieux Jean , Riboulleau Jacques , Bodo Bernard , Molho Darius 
Published: April 2009

AbstractCertaines plantes de la famille des Légumineuses contiennent des composés du type flavonique désignés par le terme “peltogynoides”, tous rattachés au squelette fondamental: [2]benzo‐pyrano[4,3‐b][1]benzopyranne, mais á divers degrés d'oxydation. Ce sont done, mis á part les substituants hydroxyles ou methoxyles des noyaux aromatiques, les dérivés de type 1:magnified image
Condensation du méthane disulfochlorure avec quelques diamines 1,2 et 1, 3 études des hétérocycles obtenus
Authors: Vincent Michel , Remond Georges , Volland Jean‐Paul 
Published: April 2009

AbstractEn milieu dilué, la condensation du méthane disulfochlorure avec quelques orthophenyléne‐diamines conduit aux benzo [e] dithiadiazépines‐1,3,4,7 tétroxyde‐2,2,4,4. Dans les měmes conditions, l'amino‐2 chloro‐5 benzhydrylamine conduit á un hétérocycle homologue. L'un des composés a donné lieu á une fragmentation intéressante par spectrométrie de masse.
Base‐catalyzed hydrolysis of 6‐aminopenicillanic acid. The kinetic and thermodynamic products
Authors: Carroll R. D. , Jung S. , Sklavounos C. G. 
Published: April 2009

AbstractIn the presence of sodium hydroxide or a β‐lactamase, 6‐APA has been shown to hydrolyze rapidly at room temperature to penicic acid 3, the kinetic product of the reaction. In a subsequent equilibration 3 isomerizes at C‐5, by way of intermediate imine 4, affording 5‐epi‐penicic acid 6 as the major hydrolysis product (∼ 95% at equilibrium). The pH and temperature parameters of equilibration are discussed and HPLC, optical rotation, proton nmr and 13C nmr data are presented.
Lithiation of 1‐benzenesulfonylimidazole. Characterization of authentic 2‐lodoimidazole
Authors: Sundberg Richard J. 
Published: April 2009

AbstractLilhiulion of 1‐betizenesulfonylimidazole takes place readily at −20° or 0° in THE. The lithium reagent gives products of addition to typical carhonyl compounds but only in low yield, lodination occurs at the 2‐position, in low yield, and authentic 2‐iodoimidazole is obtained by cleavage ol the henzenesulfonyl group.
Reinvestigation of the synthesis of 5‐arylamino‐2‐picolines
Authors: Peterson Louis H. , Tolman Richard L. 
Published: April 2009

AbstractReaction of 5‐bromo‐ or 3‐bromo‐2‐methylpyridine with o‐nitroaniline gave the corresponding N‐[2‐methyl‐5(or 3)pyridyl]‐o‐nitroanilines. Reduction to the corresponding amino derivatives and ring closure to 1‐[2‐methyl‐5(or 3)pyridyl]benzotriazole allowed the structures to be confirmed and an earlier literature report to be corrected. Displacement of bromide by anthranilic acid from 5‐bromo‐2‐methylpyridine and decarboxylation gave N‐(2‐methyl‐5‐pyridyl)aniline.
Neighboring group participation in cyclodehydration. A regiospecific isoxazole synthesis
Authors: Crawley L. S. , Fanshawe W. J. 
Published: April 2009

AbstractThe regiospecific synthesis of isoxazoles 2, 11, 14, and 15 is explained in terms of neighboring group participation of the ortho nitrogen of the heterocyclic ring in the cyclodehydration step.
1,2,3‐Selenadiazolyl‐1,3,4‐oxadiazole, 1,2,3‐Thiadiazolyl‐1,3,4‐oxadiazole and 5‐(1,2,3‐Thiadiazolyl)‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazoles
Authors: Shafiee A. , Lalezari I. , Mirrashed M. , Nercesian D. 
Published: April 2009

AbstractA series of 5‐substituted‐2‐(4‐alkyl or phenyl‐1,2,3‐thia(or selena)diazol‐5‐yl)‐1,3,4‐oxadiazoles were prepared. 5‐Substituted‐2‐(4‐phenyl‐1,2,3‐selenadiazol‐5‐yl)‐1,3,4‐oxadiazoles upon pyrolysis afforded the corresponding alkynes. Also, a series of 5‐substituted‐4‐amino‐3‐(1,2,3‐thiadiazol‐5‐yl)‐s‐triazoles and 5‐(1,2,3‐thiadiazolyl)‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazoles were prepared.
Synthèse et structure de triazoline‐1,2,4 thiones‐5 possédant en 3 ou 4 un substituant dialkylaminoèthyle
Authors: Hénichart Jean‐Pierre , Houssin Raymond , Lablanche Brigitte 
Published: April 2009

AbstractL'addition d'un hydrazide sur un isothiocyanate conduit à la formation d'un acylthiosemi‐earbazide. Lorsque I'un des composés de départ posséde une chaǐne dialkylaminoéthyle, une hétérocyclisation en triazolinethione s'effectue d'emblée.Une étude physicochimique de quelques‐uns de ces composés de cyclisation est reportée et un mécanisme permettant d'interpréter leur fragmentation en spectrographie de masse est proposé.
6‐ And 7‐Substituted 4H‐Pyrido[1,2‐a] pyrimidin‐4‐ones. Synthesis via the Acid‐catalyzed Isomerization of 2‐(Acetoacetamido)pyridines
Authors: Yale Harry L. , Spitzmiller E. R. 
Published: April 2009

AbstractA novel procedure has been developed for converting a variety of substituted 2‐(aceto‐acetamido)pyridines into substituted 4H‐pyrido[1,2‐a]pyrimidin‐4‐ones. The reaction involves an acid‐catalyzed isomerization of the 2‐(acetoacetamido)pyridine derivatives into the corresponding enamines, under conditions that permit the latter to undergo cyclization to the 4‐one, in situ. The method has been employed to prepare a number of hitherto unknown 2,6‐ and 2,7‐di‐ and 2,7,9‐trisubstituted 4H‐pyrido[1,2‐a]pyrimidin‐4‐ones.
An Investigation on the thermolytic conversions of 5‐Diazouracils into 1,2,3‐Triazoles
Authors: Thurber T. Craig , Townsend Leroy B. 
Published: April 2009

AbstractThe thermolysis of 5‐diazo‐6‐methoxy‐1‐methyl‐1,6‐dihydrouracil (1) has afforded methyl N‐(1‐methyl‐1,2,3‐triazol‐4‐oyl)carbamate (2), bis‐(1‐methyl‐1,2,3‐triazol‐4‐oyl)amine (3) and di‐methylcarbimate (4). The reaction was shown to proceed with the initial formation of 2 followed by a subsequent disproportionation of 2 to give 3 and 4. A similar thermolysis of 5‐diazo‐6‐ethoxy‐1‐methyl‐1,6‐dihydrouracil (9) gave ethyl N‐(1‐methyl‐1,2,3‐triazol‐4‐oyl)car‐bamate (10) as the sole product. Double labeling experiments have indicated that a major pathway for these reactions involves an intermolecular transfer of the C‐6 substituent to the C‐2 position.
N‐substitution in the 2‐amino‐ and 2,7‐diaminophenoxazin‐3‐one ring system. Application to the preparation of actinomycin D analogs
Authors: Chaykovsky Michael , Modest Edward J. , Sengupta Sisir K. 
Published: April 2009

AbstractA method is described for the direct N2‐monoalkylation of the 2‐aminophenoxazin‐3‐one system by treatment with dimethylsulfonium methylide in DMSO‐THF, which acts as a base by abstracting a proton from the 2‐amino function to form a stabilized anion, which is then alkylated by reaction with an alkyl halide. Selective N7‐monoalkylation of the 2,7‐diaminophenoxazin‐3‐one system can be accomplished by reaction with aromatic aldehydes in glacial acetic acid to give Schiff bases, which are then reduced with dimethylamine borane. These reactions have been applied to the preparation of N2‐benzyl‐ and 7‐benzylaminoactinomycin D.
Synthesis of tris and tetraisoxazole compounds
Authors: Auricchio S. , Ricca A. , De Pava O. Vajna 
Published: April 2009

AbstractThe syntheses of new tris (XII) and tetraisoxazole compounds (XIII and XIV) are reported; all synthons have been described. New isoxazole chlorooximes (V and VIII) have been prepared for this purpose and their behavior was examined.
Fused s‐Triazino heterocycles. VI. 1,9,9b‐Triazaphenalenes
Authors: Shaw John T. , Prem Suzanne 
Published: April 2009

AbstractDerivatives of 1,9,b‐triazaphenalene have been prepared by reacting alkyl‐N‐cyanoimidates with 2,6‐bis(cyanomethyl)pyridine.
The reaction of 1,2‐dioxo‐1,2‐dihydropyrrolo‐[3,2,1‐kl] phenothiazine with amines
Authors: Pinto Ângelo C. , Hollins Richard A. 
Published: April 2009

AbstractThe title compound I reacts with aliphatic amines producing ring‐opened keto‐amides of structure VII and with anilines forming imines of structure VIII.
Fused‐s‐triazino heterocycles. VII. 1,3,5,7,9b‐Pentaazaphenalene and 1,3,4,6,8,9b‐hexaazaphenalene
Authors: Shaw John T. , Kyler Keith S. , Anderson Mark D. 
Published: April 2009

AbstractCyclization of 2,6‐diaminopyrazine to two new heterocyclic ring systems, 1,3,5,7,9b‐pentaazaphenalene and 1,3,4,6,8,9b‐hexaazaphenalene is reported.
A simple synthesis of 8‐(trifluoromethyl)‐2,3,5,6,11,12,14,15‐octahydro‐1H,4H,10H, 13H‐diquinolizino[9,9a,1‐bc:9′,9a',1‐hi] xanthylium perchlorate, an efficient dye
Authors: Haley Laser N. F. 
Published: April 2009

AbstractA one‐step procedure is described for the preparation of the title compound I, an efficient laser dye operating in the red region.
2,3‐Fused 1,8‐Naphthyridines
Authors: Thummel Randolph P. , Kohli Dalip K. 
Published: April 2009

AbstractThe Friedlander condensation of 2‐aminonicotinaldehyde with cyclic ketones leads to the preparation of 2,3‐fused 1,8‐naphthyridines. The spectral properties and basicities of these molecules are discussed.