bluuebunny/crossref_metadata_2025_split huggingface dataset:
An anomalous reaction of 10‐chloro‐5H‐benzoxazolo[3,2‐a]quinolin‐5‐one with sodium diethyl malonate to form 9‐chloro‐8‐ethoxy‐12‐hydroxy‐5H‐dibenz[c,f]quinolizin‐5‐one
Authors: Kim Dong Han 
Published: March 2009

AbstractTreatment of 10‐chloro‐5H‐benzoxazole[3,2‐a]quinolin‐5‐one (I) with an excess of sodium diethyl malonate at 190° for 3 hours in hexamethylphosphoramide gave, in 38% yield, 9‐chloro‐8‐ethoxy‐12‐hydroxy‐5H‐dibenz[c,f]quinolizin‐5‐one (IV) which, on heating with acetic anhydride, afforded monoacetylated product, V. A possible reaction mechanism for the novel ring expansion reaction is suggested.
Studies on v‐triazoles. Part III. On the nitration of 9‐oxo‐1H,9H‐benzopyrano[2,3‐d]‐v‐triazole
Authors: Buckle Derek R. 
Published: March 2009

AbstractThe nitration of 9‐oxo‐1H,9H‐benzopyrano[2,3‐d]‐v‐triazole (1) leads not to the expected benzenoid substitution product 2 but to initial attack on the triazole moiety resulting in fission to 3‐diazo‐2‐nitrimino‐2H‐[1]benzopyran‐4‐yl oxide (3). Mild hydrolysis of 3 results in cleavage of the nitrimine to give 3‐diazo‐2‐oxo‐2H‐[1]benzopyran‐4‐yl oxide (4). Further nitration of 3 under more forcing conditions leads to the 6‐nitro derivative of 3 which also undergoes facile hydrolysis to a diazocoumarin.
Mass spectra of synthetic mitosenes
Authors: Hodges John , Schram Karl H. , Baker Peter F. , Remers William A. 
Published: March 2009

AbstractThe mass spectral fragmentation of a series of 10 mitosene analogs is described. Major pathways arise through decomposition of the substituents in the 1 and 10 positions and are unaffected by the substituent in the 7 position. The base peak in the spectrum, in most cases, is represented by the basic mitosene ring. The patterns are general for this series of compounds and may have application in elucidating the structure of the DNA alkylation sites involved in reactions with mitosenes or natural mitomycins.
N‐ethoxycarbonylamidines as starting materials and intermediates in the synthesis of heterocyclic compounds
Authors: Dean W. D. , Papadopoulos E. P. 
Published: March 2009

AbstractTreatment of N‐ethoxycarbonylthioamides (1) with primary aromatic amines yields N‐aryl‐N′‐ethoxy‐carbonylamidines (2), which thermally cyclize to 2‐aryl‐4(3H)‐quinazolinones (6). Analogous reactions of 1 with ethyl 3‐aminocrotonate and with 2‐amino‐2‐thiazoline lead respectively to ethyl 2‐aryl‐3,4‐dihydro‐6‐methyl‐4‐oxo‐5‐pyrimidinecarboxylates (10) and to 2‐aryl‐6,7‐dihydro‐4H‐thiazolo[3,2‐a]‐1,3,5‐triazin‐4‐ones (14), presumably through the corresponding N‐ethoxycarbonylamidines.
Synthesis of 2‐alkoxy‐6‐aryl‐5‐cyano‐4(3H)‐pyrimidinones
Authors: Pérez Miguel A. , Soto José L. 
Published: March 2009

AbstractThe reaction of methyl 3‐aryl‐2‐cyano‐3‐methoxypropenoates 1 with cyanamide and sodium methoxide in methanol afforded after acid hydrolysis the methyl 3‐[(aminocarbonyl)amino]‐3‐aryl‐2‐cyanopropenoates 4. By performing the reaction in higher boiling alcohols the 2‐alkoxy‐6‐aryl‐5‐cyano‐4(3H)‐pyrimidinones 2 were obtained in good yields.
Synthése de nouvelles amidines bicycliques. 1. Dérivés de l'imidazole, du triazole‐1,3,4 et du tétrazole
Authors: Langlois Michel , Guillonneau Claude , Vovan Tri , Meingan Jean‐Pierre , Maillard Jacques 
Published: March 2009

AbstractLes auteurs décrivent la synthèse de pyrrolo[1,2‐a]imidazoles, pyrrolo[1,2‐c]triazoles et pyrrolo[1,2‐a]tétrazole et quelques homologues contenant un cycle pyridine ou azépine à la place du pyrrole. Ces composés sont obtenus à partir d'amidines cycliques, au moyen de réactions décrites pour d'autres hétérocycles.
Reaction of tetramethyl‐1,2‐dioxetane with triphenylphosphine: Activation parameters for the formation of 2,2‐dihydro‐4,4,5,5‐tetramethyl‐2,2,2‐triphenyl‐1,3,2‐dioxaphospholane
Authors: Baumstark Alfons L. , Barrett Morgan , Kral Kathleen M. 
Published: March 2009

AbstractThe reaction of tetramethyl‐1,2‐dioxetane (1) and triphenylphosphine (2) in benzene‐d6 produced 2,2‐dihydro‐4,4,5,5‐tetramethyl‐2,2,2‐triphenyl‐1,3,2‐dioxaphospholane (3) in ˜90% yield over the temperature range of 6–60°. Pinacolone and triphenylphosphine oxide (4) were the major side products [additionally acetone (from thermolysis of 1) and tetramethyloxirane (5) were noted at the higher temperatures]. Thermal decomposition of 3 produced only 4 and 5. Kinetic studies were carried out by the chemiluminescence method. The rate of phosphorane was found to be first order with respect to each reagent. The activation parameters for the reaction of 1 and 2 were: Ea ≅ 9.8 ± 0.6 kcal/mole; ΔS≠ = −28 eu; k30° = 1.8 m−1sec−1 (range = 10–60°). Preliminary results for the reaction of 1 and tris (p‐chlorophenyl)phosphine were: Ea ˜ 11 kcal/mole, ΔS≠ = −24 eu, k30° = 1.3 M−1sec−1 while those for the reaction of 1 and tris(p‐anisyl)phosphine were: Ea ˜ 8.6 kcal/mole, ΔS≠ = −29 eu, k30° = 4.9 M−1 sec−1.
Radical anions from N,N′‐dimethylisoindigo and its methoxyderivatives
Authors: Bruni P. , Cardellini L. , Cardillo B. , Tosi G. 
Published: March 2009

AbstractN,N′‐Dimethylisoindigo and four methoxy derivatives have been synthesized and reduced to the corresponding radical anions by t‐BuOK‐DMSO. The epr spectra are reported and discussed.
The preparation of 5‐phenacylisoxazoles and 5‐hydroxyphenyl‐isoxazoles and ‐pyrazoles by the condensation of C(a)‐dianions with ethyl benzoylacetate and methyl salicylate
Authors: Livingston Melanie J. , Chick Marlisa F. , Shealy Ernest O. , Beam Charles F. 
Published: March 2009

AbstractC(α), O‐Dilithiooximes and C(α), N‐Dilithiophenylhydrazones were prepared in an excess of lithium diisopropylamide (LDA). The former was condensed with ethyl benzoylacetate and methyl salicylate, and the latter condensed with methyl salicylate. The resulting precyclization intermediates were then treated with aqueous acid, which was followed by cyclodehydration to give phenacylisoxazoles and hydroxyphenyl‐isoxazoles and ‐pyrazoles.
Synthesis of benzo[b]phenanthro[d]thiophenes
Authors: Pratap Ram , Lee Milton L. , Castle Raymond N. 
Published: March 2009

AbstractThe synthesis of benzo[b]phenanthro[1,2‐d]thiphene (1), benzo[b]phenanthro[4,3‐d]thiophene (2), benzo‐[b]phenanthro[2,1‐d]thiophene (3) and benzo[b]phenanthro[3,4‐d]thiophene (4) from appropriately substituted olefines by photochemical cyclodehydrogenation is described. The photolysis of olefin 9 gave a mixture of 4 and anthra[1,2‐b]benzo[d]thiophene (5).
Studies on new routes for the synthesis of 4‐ and 5‐aminoimidazole nucleoside derivatives
Authors: García‐Lopez M. Teresa , Herranz Rosario 
Published: March 2009

AbstractThe synthesis of urethane protected 4‐ and 5‐aminoimidazole nucleoside derivatives 4 and 9 by two different routes is described. These routes are transformation of the carboxylate substituted imidazole nucleoside 1 via a Curtius rearrangement to give 4 and direct ribosylation of the imidazole base 6 to give a mixture of positional isomers 7 and 8, which by deacetylation afford 4 and 9, respectively. The convenience of each route depended on the positional isomer to be synthesized.
Chemistry of the phenoxathiins and isosterically related heterocycles. XX. Assignment of the 13C‐NMR spectra of phenarsazine‐10‐chloride and several substituted analogs. The effect of substitution on the anisotropic reorientation of the phenarsazine system
Authors: Jay Michael , Martin Gary E. 
Published: March 2009

AbstractThe total assignment of the 13C‐nmr spectra of phenarsazine‐10‐chloride and several substituted analogs is reported. Spin‐lattice (T1) relaxation measurements have shown these systems to reorient anisotropically. In the case of the parent system and the 3‐chloro substituted system, the axis of anisotropic reorientation has been shown to pass approximately through the center of the molecule. In the case of benzo[c]phenarsazine‐7‐chloride, the axis of anisotropic reorientation, which has been accurately defined, is shifted 23° from that in the previous cases, the shift occurring in the direction of the benzo‐moiety.
Les systèmes biphasiques. 3. Alkylation des purines en catalyse par transfert de phase
Authors: Hedayatullah Mir 
Published: March 2009

AbstractLa méthylation de l'adénine en catalyse par transfert de phase fournit sélectivement la méthyl‐9 adénine (98%), tandis que sa benzylation conduit à la benzyl‐9 adénine comme produit majoritaire à cǒté de très faibles quantités de benzyl‐3 adénine. L'alkylation de la xanthine, de la théobromine et de la théophylline par la měme technique donne naissance aussi aux dérives N‐alkylés correspondants avec de hauts rendements à l'exclusion de tout autre régioisomere O‐alkylé. Cette technique d'alkylation constitue, tant par sa simplicité que par sa sélectivityé, une amélioration considerable des méthodes conventionnelles.
Synthèse de triazolo‐1,2,3 nucléosides par cycloaddition entre azotures de glycosyle et acétyléniques ativés
Authors: Chrétien Francoise , Gross Bernard 
Published: March 2009

AbstractCette note traite d'une nouvelle méthode de préparation d'azotures de glycosyle sur lesquels la cycloaddition de composés acétyléniques activés pour donner des triazolo‐1,2,3 nucléosides a été améliorée. Ceci a été réalisé en séries allo‐, ribo‐ et arabinofurannoses et mannopyrannose avec le propiolate de méthyle et l'acetylene dicarboxylate d'éthyle.
Sur l'orientation et les anomalies de l'acetylation des Bz‐méthoxy nitro‐2 benzofurannes
Authors: Clavel Jean‐Marc , Guillaumel Jean , Demerseman Pierre , Royer Rene 
Published: March 2009

AbstractAlors que le nitro‐2 benzofuranne lui‐měme n'a pu ětre acétylé selon Friedel et Crafts, ses derives meth‐oxyles en 4, en 5 ou en 7 sont susceptibles de l'ětre, dans des conditions expérimentals adaptees a chaque cas. Ils donnent ainsi, respectivement, les acétyl‐7 méthoxy‐4 nitro‐2 benzofuranne acetyl‐4 méthoxy‐5 nitro‐2 benzofuranne et acétyl‐4 méthoxy‐7 nitro‐2 benzofuranne.Il se forme en měme temps de la dihydro‐2,3 méthoxy‐4 (méthoxy‐4′ nitro‐2′ benzofuryl‐7′)‐3 benzofurannone‐2 a partir du méthoxy‐4 nitro‐2 benzofuranne et de la chloro‐3 dihydro‐2,3 méthoxy‐5 benzofurannone‐2 à partir du méthoxy‐5 nitro‐2 benzofuranne. Celui‐ci subit en outre une chloration tout à fait singuliére en position 4.Quant au méthoxy‐6 nitro‐2 benzofuranne, il ne peut ětre acétyle sans decomposition dans les měmes con‐ditions que ses isoméres méthoxylés en 4, en 5 ou en 7.
Preparation of some 4H‐1,3,2‐benzothioxaborine and 1H,4H‐1,3,2‐benzazoxaborine
Authors: Bernard Angela Maria , Cocco Maria Teresa , Plumitallo Antonio , Secci Mario 
Published: March 2009

AbstractThe preparation of some 2‐substituted‐4H‐1,3,2‐benzothioxaborine and 2‐substituted‐1H,4H‐1,3,2‐benzazoxaborine is described.
Synthesis of 2‐S‐dioxo isosteres of purine and pyrimidine nucleosides. II
Authors: Fernández‐Resa Piedad , Stud Manfred 
Published: March 2009

AbstractThe preparation of glucosyl and ribosyl derivatives of 3,4,5‐triamino‐2H‐1,2,6‐thiadiazine 1,1‐dioxide (2), 7‐amino‐4H‐furazano[3,4‐c]‐ and 7‐amino‐1H, 4H‐imidazo[2,3‐c][1,2,6]thiadiazine 5,5‐dioxide (3 and 4 respectively) is described. Different synthetic approaches have been used.
Synthesis of 6‐(2‐nitrobenzyl)‐3,5‐dioxo‐2,3,4,5‐tetrahydro‐as‐triazine and some derivatives
Authors: Hajpál István , Berenyi Edit 
Published: March 2009

Abstract6‐(2‐Nitrobenzyl)‐3,5‐dioxo‐2,3,4,5‐tetrahydro‐as‐triazines were prepared as intermediates for investigations aimed at the synthesis of as‐triazino[5,6‐b]quinolines. The substances were obtained by new methods based on the elucidation of stereochemical conditions.
A carbon 13‐NMR assignment study of a series of oxetanes derived from carbonyl compounds and furan and thiophene derivatives
Authors: Bolívar R. A. , Doppert K. , Rivas C. 
Published: March 2009

AbstractThe assignment of the carbon‐13 nmr resonances of a series of oxetanes derived from the photoaddition of benzophenone and 2‐naphthaldehyde to furan and some of its methyl derivatives and of benzophenone to 2,5‐dimethylthiophene has been made. The assignments were made by chemical shift arguments, by the use of C‐13 labelling when required and different decoupling techniques. This information may be useful in the identification of new compounds with analogous carbon skeleton.
Action de réactifs nucléophiles sur les phényl‐5 thiéno[3,2‐b]pyrannone‐7 et phényl‐2 benzo[b]thiéno[3,2‐b]pyrannone‐4
Authors: Netchitaílo Pierre , Decroix Bernard , Morel Jean 
Published: March 2009

AbstractNous étudions la réactivité de la phényl‐5 thiéno[3,2‐b]pyrannone‐7 et de la phényl‐2 benzo[b]thiéno‐[3,2‐b]pyrannone‐4 vis à vis de reactifs nucleophiles et la comparons à celle des benzopyrannones.
Reactions between 4‐hydroxy‐6‐methyl‐2‐pyrone and aldehydes both in the absence and the presence of added thiols
Authors: de March P. , Moreno‐Mañas M. , Pi R. , Trius A. 
Published: March 2009

AbstractAldehydes react with 4‐hydroxy‐6‐methyl‐2‐pyrone, 2, under Knoevenagel conditions to afford very elec‐trophilic intermediates, which can be trapped by more 2 or thiols to give dilactones 3 or monolactones 4.
Synthése de la benzopyranno[1][2,3‐b]quinoxalinone‐12
Authors: Vinot Nicole , Maitte Pierre 
Published: March 2009

AbstractLes benzyl‐3 quinoxalinones‐2 sont obtenues par condensation de l'o‐phénylénediamine avec les acides phénylpyruviques. Ces quinoxalinones subissent facilement des substitutions en ‐2, qui permettent de préparer un certain nombre de dérives, mais les essais de cyclisation de ces composes en 12H‐benzopyranno‐[1][2,3‐b]quinoxaline ont échoue. Une suite de reactions classiques effectuees a partir du phenoxy‐2 quin‐oxaline carboxylate‐3 d'éthyle permet cependant d'atteindre cet héterocycle nouveau.
Fused‐s‐triazino heterocycles IX. 1,3,4,6,9b‐pentaazaphenalenes and 1,3,6,9b‐tetraazaphenalenes: Amino and alkoxy derivatives
Authors: Shaw John T. , Coffindaffer Timothy W. , Stimmel Julie B. , Lindley Patricia M. 
Published: March 2009

AbstractThe trichloromethyl group served as a useful leaving group in nucleophilic displacement reactions by a variety of substituted amines and alcohols (the latter under base catalysis) on 2‐trichloromethyl‐5‐methyl‐1,3,4,6,9b‐pentaazaphenalene (1a) and 2‐trichloromethyl‐4‐cyano‐1,3,6,9b‐tetraazaphenalene (2a). The reaction conditions were mild and the yields of the corresponding 2‐substituted amino and alkoxy derivatives were generally good.
Studies on quinones. VIII. The application of michael adducts from 2‐hydroxy‐1,4‐naphthoquinones for the preparation of dihydronaphthopyrandiones
Authors: Cassis R. , Tapia R. , Valderrama J. 
Published: March 2009

AbstractDihydronaphthopyran‐5,10‐diones 7,13, 16 and their corresponding dihydronaphthopyran‐5,6‐diones 8, 14,17 have been obtained starting from Michael adducts of 2‐hydroxy‐ and 2‐hydroxy‐7‐methoxy‐1,4‐naph‐thoquinone (1, 9). An efficient synthesis of hydroxyhydrolapachol (4) employing 2‐hydroxy‐3‐(3‐oxobutyl)‐1,4‐naphthoquinone (5) is described.
Acylations of 1,10‐dilithiophenothiazine. A new synthesis of 1‐formylphenothiazine
Authors: Hallberg Anders , Martin Arnold 
Published: March 2009

AbstractThe synthesis of 1‐formyl‐, 1‐benzyyl‐, 1‐anisoyl‐, and 1‐nicotinyl‐phenothiazines (1–4) resulting from the reaction of the corresponding amids with 1,10‐dilithiophenothiazine (5) is reported. The site of attachment on 1,10‐dilithiophenothiazine, based on the nature of some different acylating reagents, is also discussed.
Synthèse d'amino‐3 thiophènes a partir d'aryl‐et d'hétaryl‐acétonitrile
Authors: Kirsch G. , Cagniant Mme D. , Cagniant P. 
Published: March 2009

AbstractPar application de la synthèse de Fiesselmann, les auteurs décrivent la préparation d'amino‐3 thiophènes substitués par des groupements aryles ou hétaryles.
The stereochemistry of organosulfur compounds. XIX. The crystal and molecular structure of 10‐(1,3‐dithiolan‐2‐ylidene)‐10H‐indeno[1,2‐f]‐1,2,3,4,5‐pentathiepin
Authors: Korp James D. , Bernal Ivan , Watkins Steven F. , Fronczek F. R. 
Published: March 2009

AbstractThe molecular structure of 10‐(1,3‐Dithiolan‐2‐ylidene)‐10H‐indeno[1,2‐f] ‐1,2,3,4,5‐pentathiepin S7C12H89 has been determined by single crystal X‐ray diffraction. The crystals are triclinic, space group PI, with two molecules in a unit cell of dimensions α = 8.931(2), b = 9.387(2), c = 10.175(2) Å, α = 75.73(2), β = 73.35(1), γ = 64.37(2)°. The structure was solved by direct methods, and refined to a final R value of 3.3% for 1925 independent reflections. The molecule consists of an indene core with a nearly co‐planar dithiolane and a fused pentasulfide chain. The S5C2 ring is in the chair configuration, with an average SS distance of 2.052 Å. There is no variation of bond lengths as is frequently seen in multi‐sulfur chains. The indenone ring shows no evidence of any delocalization, while the dithiolane ring is disordered at the two methylene positions. No attempt was made to resolve the disorder, since it is frequently seen and has been thoroughly investigated previously.
Studies on uracil derivatives and analogs. Syntheses of 5‐(βt‐trimethylsilyl)ethynyluracil and 5‐ethynyluracil
Authors: Kundu Nitya G. , Schmitz Scott A. 
Published: March 2009

Abstract5‐(α‐Chlorovinyl)‐2,4‐dichloropyrimidine (I) on treatment with sodium methoxide in methanol was converted to 2,4‐dimethoxy‐5‐ethynylpyrimidine (II) which was silylated by t‐butyl lithium and chlorotrimethylsilane to 2,4‐dimethoxy‐5‐β‐trimethylsilyl)ethynylpyrimidine (IV). Compound IV on deblocking with trimethylsilyl iodide yielded 5‐(β‐trimethylsilyl)ethynyluracil (V), which on treatment with sodium hydroxide in methanol was converted to 5‐ethynyluracil (VI).
Syntheses and reactions of some 2,3‐disubstituted pyrazine monoxides
Authors: Ohta Akihiro , Masano Sawako , Iwakura Sachiko , Tamura Akiko , Watahiki Hiroko , Tsutsui Mayumi , Akita Yasuo , Watanabe Tokuhiro , Kurihara Teruo 
Published: March 2009

AbstractThe reactions of 2,3‐dimethyl‐ (4), 2,3‐diphenyl‐ (6), and 2‐methyl‐3‐phenyl‐pyrazine monoxides (8 and 9) with phosphoryl chloride and acetic anhydride resulted in giving monochloro‐ and monacetoxy‐pyrazines in almost all cases. However, the reaction of 6 with acetic anhydride afforded exceptionally a diacetoxydihydro‐pyrazine. These products were converted further to hydroxy or dichloro derivatives.
Structures de deux β‐énaminoesters cycliques: l'α‐(tétrahydropyrrolidinylidéne‐2) acétate d'éthyle et l'α‐(hexahydroazepinylidéne‐2) acétate d'éthyle
Authors: Philoche‐Levisalles Michèle , Bois Claudette , Célérier Jean‐Pierre , Lhommet Gérard 
Published: March 2009

AbstractLa détermination des structures des α‐(tétrahydropyrrolidinylidène‐2) et α‐(hexahydroazepinylidéne‐2) acétates d'éthyle a été effectuée par diffraction des RX sur monocristaux. II est ainsi montré qu'á l'etat solide ces composés sont sous forme β‐énaminoesters de configuration Z et qu'il existe des liaisons intra et intermoleculaires.
Isomeric tropane analogues of histamine H2‐receptor antagonists
Authors: Bagley Jerome R. , Riley Thomas N. 
Published: March 2009

AbstractIn an attempt to investigate stereochemical requirements of antagonists of the histamine H2‐receptor, tropane analogues of cimetidine and metiamide have been synthesized possessing axial and equatorial N‐methylthiourea and N‐methyl‐N‐cyanoguanidine moieties at the 3‐position of the tropane system. The tropane analogues of this study have been fully characterized with regard to configuration at C‐3 and to conformation of the piperidine ring of the tropane nucleus.
Hydroxide‐catalyzed synthesis of heterocyclic aromatic amine derivatives from nitriles
Authors: Smyrl Norman R. , Smithwick Robert W. 
Published: March 2009

AbstractA generalized method for synthesizing a wide variety of heterocyclic aromatic amine derivatives from nitriles by use of hydroxide catalysts is presented. Nitrile dimers (3‐aminocrotononitrile and dicyandiamide) and a dimer analog (anthranilonitrile) react with monomeric nitriles in the presence of hydroxide to form respectively, aminopyrimidines, diaminotriazines and aminoquinazolines.
Studies on the chemical synthesis of potential antimetabolites. 30. Regioselective introduction of a chlorine atom into the imidazo[4,5‐b]pyridine nucleus
Authors: Itoh Tokuo , Ono Kazuo , Sugawara Tomokazu , Mizuno Yoshihisa 
Published: March 2009

AbstractReactions of some imidazo[4,5‐b]pyridine 4‐oxides with phosphoryl chloride are described. Treatment of N‐1‐substituted imidazo[4,5‐b]pyridine 4‐oxides with phosphoryl chloride led to the predominant formation of 7‐chloro derivatives. This feature was successfully applied to the preparation of a chloroimidazo[4,5‐b]pyridine nucleoside, which served as an important precursor of 1‐deazaadenosine.
Synthesis of 1,4‐benzodiazepino[4,5‐d][1,4]benzoxazepines
Authors: Effland Richard C. , Helsley Grover C. , Tegeler John J. 
Published: March 2009

AbstractThe novel 1,4‐benzodiazepino[4,5‐d][1,4]benzoxazepine ring system has been constructed via preformed benzoxazepine intermediates. Several derivatives have been prepared as potential anxiolytic agents.
Synthesis of substituted N‐(2,4‐dioxo‐1,2,3,4‐tetrahydroquinazolinyl)benzamides and N‐(2‐thiono‐4‐oxo‐1,2,3,4‐tetrahydroquinazolinyl)benzamides
Authors: Chau Nguyen , Saegusa Yasuo , Iwakura Yoshio 
Published: March 2009

AbstractSubstituted N‐(2,4‐Dioxo‐1,2,3,4‐tetrahydroquinazolinyl)benzamides (3a‐g) and substituted N‐(2‐Thiono‐4‐oxo‐1,2,3,4‐tetrahydroquinazolinyl)benzamides (4a‐g) were synthesized in one step from the reaction of methyl anthranilate with 2‐aryl‐1,3,4‐oxadiazolin‐5‐ones (1a‐g) and 2‐aryl‐1,3,4‐oxadiazoline‐5‐thiones (2a‐g), respectively, in m‐cresol at 150–160°. Alternative routes leading to the formation of 3a and 4a are also reported.
Mesoionic purinone analogs. VIII. Synthesis and properties of mesoionic 5‐substituted‐6‐methylimidazo[1,2‐c]pyrimidine‐2,7‐diones
Authors: Coburn Robert A. , Taylor Michael D. 
Published: March 2009

AbstractMesoionic imidazo[1,2‐c]‐pyrimidine‐2,7‐diones 1a‐c, analogs of purine‐2,8‐dione, were prepared from 4‐amino‐l‐methylpyrimidin‐6‐ones 6a‐c. These mesoionic purinone analogs were found to exist predominantly in the C3‐H tautomeric form 1 and to undergo hydrolytic ring‐opening reactions to produce 2‐(4‐imidazol‐idon‐2‐ylidenyl)acetamides. Reaction of 1c with dimethyl acetylene dicarboxylate produced triazacyclopent‐[cd]indene 25 via 1,3‐dipolar cycloaddition.
Cycloaddition reactions of N‐p‐toluenesulfonylimino derivatives of quinoline and isoquinoline. A route to pyrazolo[1,5‐a]quinolines and pyrazolo[5,1‐a]isoquinolines
Authors: Sundberg Richard J. , Ellis James E. 
Published: March 2009

AbstractN‐p‐Toluenesulfonylimino ylides of quinoline and isoquinoline give cycloadducts with electrophilic acetylenes at 105°. The adducts are spontaneously aromatized under the conditions of their formation by elimination of p‐toluenesulfmic acid to give pyrazolo[1,5‐a]quinolines and pyrazolo[5,1‐a]isoquinolines, respectively. The orientation of cycloaddition is the same as for N‐amino ylides for acetylenic esters. The ad‐ducts from p‐nitrophenylacetylene are formed by addition of the imino nitrogen to the unsubstituted acetylenic carbon. The orientation and unreactivity of phenylacetylene indicate that the cycloaddition is controlled by dipole HOMO‐dipolarophile LUMO interactions.
Reactions of N‐heteroarylformamide oximes and N‐heteroarylacetamide oximes with N,N‐dimethylformamide dimethyl acetal. Synthesis of 2‐methyl‐s‐triazolo[1,5‐x]azines and N‐methylcyanoaminoazines
Authors: Stanovnik Branko , Štimac Anton , Tišler Miha , Verček Bojan 
Published: March 2009

AbstractN‐Heteroarylformamide oximes 3 (R  H) were converted with N,N‐dimethylformamide dimethyl acetal (DMFDMA) into N‐heteroaryl‐N‐methylcyanoamino compounds 5, as the main products. In some instances N‐heteroarylcyanoamino compounds 4, cyanoimino compounds 7, and some other products, such as 9 and 10 were also formed. On the other hand, N‐heteroarylacetamide oximes 3 (R  CH3) were cyclized under the same reaction conditions into 2‐methyl‐s‐triazolo[1,5‐x]azines (6). N‐Heteroarylacetamide O‐methyl oximes 11 and 12 were prepared from the corresponding acetamidines 2 (R  CH3) and O‐methylhydroxylamine.