bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mass spectra of azabicyclospirohydantoins
Authors: Trigo G. G. , Ballesteros P. , Espada M. , Santos E. , Gálvez E. , Avendaño C. , Martínez M. 
Published: March 2009

AbstractThe mass spectra of some N‐substituted nortropane and granataninespirohydantoins are compared with those of N‐substituted 3‐azabicyclo[3.2.1]octane‐8‐spiro‐, 3‐azabicyclo[3.3.1]nonane‐9‐spiro‐, 8‐azabicyclo‐[4.3.1]decane‐10‐spiro‐ and 3,7‐diazabicyclo[3.3.1]nonane‐9‐spiro‐5′‐hydantoins. Mass spectra data of monothio‐ and dithio‐tropanespirohydantoins are also included. Mass fragmentation and structure relationships of these molecules have been established.
Nucleosides. 117. Synthesis of 4‐oxo‐8‐(β‐D‐ribofuranosyl)‐3H‐pyrazolo[1,5‐a]‐1,3,5‐triazine (OPTR) via 3‐amino‐2N‐carbamoyl‐4‐(β‐D‐ribofuranosyl)pyrazole (ACPR) derivatives
Authors: Chu C. K. , Watanabe K. A. , Fox J. J. 
Published: March 2009

AbstractReaction of 2‐formyl‐2‐(2,3‐O‐isopropylidene‐5‐O‐trityl‐D‐ribofuranosyl)acetonitrile (VII) with semicarbazide hydrochloride followed by sodium ethoxide treatment afforded an α,β‐mixture of 3‐amino‐2N‐carbamoyl‐4‐(2,3‐O‐isopropylidene‐5‐O‐trityl‐D‐ribofuranosyl)pyrazole (IX). Conversion of IX to 4‐oxo‐8‐(2,3‐O‐isopropylidene‐5‐O‐trityl‐D‐ribofuranosyl)‐3H‐pyrazolo[1,5‐a]‐1,3,5‐triazine (XIII) was achieved by treatment of IX with ethylorthoformate. The β‐isomer IXb gave only the β‐isomer XIIIb, and the α‐isomer IXa was converted exclusively into the α‐isomer XIIIa. Upon deprotection with 3% n‐butanolic hydrogen chloride, both IXa and IXb gave the same mixture of the α‐ and β‐isomers of 3‐amino‐2N‐carbamoyl‐4‐(D‐ribosyl)pyrazole, which were separated by chromatography.The syntheses of the hitherto unknown compounds, 3‐amino‐2N‐carbamoylpyrazole (IVa) and its 4‐methyl analog (IVb) are also reported. Experimental details of the synthesis of 3‐amino‐4‐(2,3‐O‐isopropylidene‐5‐O‐trityl‐β‐D‐ribofuranosyl)pyrazole (XIIb), an important intermediate for “purine‐like” C‐nucleosides, are also described.
The mechanism of the bischler‐napieralski reaction
Authors: Nagubandi Sreeramulu , Fodor G. 
Published: March 2009

AbstractThe Bischler‐Napieralski dihydroisoquinoline synthesis was proven to occur via imidoyl chlorides and the corresponding nitrilium salt. The two‐step process required much milder conditions (20°–50°) compared to drastic classical conditions of refluxing at 100°–200°. The Bischler‐Napieralski reaction is shown to share a common intermediate with two other well‐known reactions: the von Braun and the Ritter reactions.
Methylation of 2‐acylamido‐1,3,4‐thiadiazoles. An infrared, proton and carbon Nmr study
Authors: Leppard D. , Sauter H. 
Published: March 2009

AbstractThe site of methylation in 2‐acylamido‐1,3,4‐thiadiazoles can be determined by ir and Carbon‐13 nmr spectroscopy.
Stable nitroxide radicals. Reaction between 2‐cyano‐ and 4‐cyanobenzoquinoline N‐oxides and the grignard reagent
Authors: Colonna Martino , Greci Lucedio , Poloni Marino 
Published: March 2009

Abstract2,2‐Diphenylbenzoquinolinenitroxide radicals were obtained starting from 2‐phenyl‐, 2‐cyano, 4‐cyano‐benzoquinoline N‐oxides, or from unsubstituted benzoquinoline N‐oxides with phenylmagnesium bromide. The elimination of bromomagnesium hydride from the 2‐unsubstituted benzoquinoline N‐oxides and cyanomagnesium bromide from the 2‐ or 4‐cyanobenzoquinoline N‐oxides is discussed.
Quino[1,2‐c]quinazolines. I. Synthesis of quino[1,2‐c]quinazolinium derivatives and the related indazolo[2,3‐a]quinoline derivatives as analogs of the antitumor benzo[c]phenanthridine alkaloids
Authors: Phillips Steven D. , Castle Raymond N. 
Published: March 2009

Abstract9,10‐Dimethoxy‐1,2,3,4,12,13‐hexahydro‐1‐oxoquino[1,2‐c]quinazolinium perchlorate, 1,2,3,4,13,24‐hexahydro‐1‐oxo[1,3]dioxolo[4,5‐g]quino[1,2‐c]quinazolinium perchlorate, 6‐methyl‐2,3,9,10‐tetramethoxyquino‐[1,2‐c]quinazolinium perchlorate and 2,3‐dimethoxy‐13‐methyl[1,3]dioxolo[4′,5′:6,7]quino[1,2‐c]quinazolinium perchlorate were synthesized as analogs of the potent antitumor benzo[c]phenanthridine alkaloids nitidine and fagaronine. The related 2,3,8,9‐tetramethoxyindazolo[2,3‐a]quinoline and 2,3‐dimethoxy[1,3]dioxolo‐[4,5‐g]indazolo[2,3‐a]quinoline were also synthesized. Further, the novel formation of 6,7‐dimethoxy‐2‐(2‐ethylamino‐4,5‐dimethoxyphenyl)quinoline via reductive alkylation with Raney nickel in refluxing ethanol is also reported.
Entzündungshemmende wirkstoffe. VIII 5‐ und 6‐chlorierte 1‐aroylbenzotriazole
Authors: Kreutzberger Alfred , Stratmann JÖRg 
Published: March 2009

AbstractDie Umsetzung von 5‐Chlorbenzotriazol (1) mit den entsprechenden Carbonsäurechloriden (2) führt einerseits zu den (3,5‐Dinitrobenzoyl)‐ (3a), (4‐Fluorbenzoyl)‐ (3b) und (4‐Chlorbenzoyl)‐Derivaten (3c) des 5‐Chlorbenzotriazols, andererseits zu den (4‐Nitrobenzoyl)‐ (4a), (3,4,5‐Trimethoxybenzoyl)‐ (4b), (4‐Methoxybenzoyl)‐ (4c), Crotonyl‐ (4d), Cinnamoyl‐ (4e) und Pentafluorbenzoyl‐Derivaten (4f) des 6‐Chlorbenzotriazols. Insbesondere vermag 4e einen auffallenden entzündungshemmenden Effekt auszulösen.
Reactions of α,β‐unsaturated ketones with cyanoacetamide
Authors: Al‐Hajjar Farouk H. , Jarrar Adil A. 
Published: March 2009

Abstract3‐Aryl‐1‐phenyl‐2‐propen‐1‐ones Ia‐f and aroylphenylacetylenes Va‐d reacted under reflux for 3 hours with cyanoacetamide in the presence of sodium ethoxide to give the corresponding 4‐aryl‐3‐cyano‐6‐phenyl‐2‐(1H)pyridones VI. However, when ketones Ia‐e were refluxed with cyanoacetamide for one hour in the presence of sodium ethoxide or piperidine, they gave the corresponding 4‐aryl‐3‐cyano‐3,4‐dihydro‐6‐phenyl‐2‐(1H)pyridones IIIa‐e, which upon heating with selenium gave the corresponding 2‐pyridones VI. The structures of the products are based on chemical and spectroscopic evidence.
Sur la synthèse de chloro‐3 indolinones a partir de β‐nitrostyrènes diversement substitués
Authors: Guillaumel Jean , Demerseman Pierre , Clavel Jean‐Marc , Royer René 
Published: March 2009

AbstractLes dérivés méthylés, chlorés ou fluorés en ortho, en méta ou en para et le dérivé nitre en méta de la chaǐne latérule du β‐nitrostyrène donnent des chloro‐3 indolinones‐2 substituées en positions correspondantes sur l'homocycle, lorsqu'on les traite par le chlorure d'acétyle, en présence de chlorure ferrique, dans le chlorure de méthylène, è 0°. Les chlorures d'aluminium et de titane ne sont pas capables d'assurer une telle hétérocyclisation et ils fournissent seulement, dans les měmes conditions, un acide N‐acétyl chloro‐2 phényl‐2 acétohydroxamique et/ou un chlorure d'acide N‐acétoxy chloro‐2 phényl‐2 acétohydroximique.
Structure de la cis‐dihydroxy‐4,5 diphényl‐3,4 méthyl‐5 isoxazoline‐2
Authors: Philoche‐Levisalles Michèle , Bellec Christian 
Published: March 2009

AbstractLa détermination de la structure de la cis dihydroxy‐4,5 diphényl‐3,4 méthyl‐5 isoxazoline‐2 a été effectuée par diffraction des R X sur monocristaux. Elle a mis en évidence la non‐planéité du cycle isoxazolinique et l'existence de liaisons hydrogène intra et intermoléculaires.
v‐triazolines. Part XVI. Synthesis of benzothiepino[4,5‐d]‐v‐triazole derivatives
Authors: Rossi Luisa Maria , Trimarco Pasqualina 
Published: March 2009

AbstractThe cycloaddition reaction of some arylazides to enamines 4a‐f afforded v‐triazolines 5a‐i; by subsequent acid‐catalyzed hydrolysis v‐triazoles 6a‐c were obtained. The reversibility of the cycloaddition was demonstrated on the basis of spectroscopic or chemical evidences.
The biological activity and crystal structure of 2‐allylamino‐4,5‐dihydro‐7,8‐dimethoxynaphtho[1,2‐d]thiazole
Authors: Rahman A. , Van Der Helm Dick , Herd Melvin D. , Hashem M. M. , Berlin K. Darrell 
Published: March 2009

AbstractScreening data for the carcinostatic activity of 2‐allylamino‐4,5‐dihydro‐7,8‐dimethoxynaphtho[1,2‐d]‐thiazole is reported. Significant T/C values (survival ratio) were found when the title compound was used to treat colon 38 tumors in the testing program of the National Cancer Institute. A single crystal X‐ray diffraction analysis was made of the compound and revealed an essentially planar arrangement of the aromatic and heterocyclic rings. The compound crystallizes in the space group P21/c with cell dimensions a = 7.9177(27) Ǎ, b = 14.999(10) Ǎ, c = 13.237(4) Ǎ, β = 107.56(2)°, Z = 4 at ‐135 ± 2°C. The intensity data were collected at low temperature using CuKα radiation. The structure was determined by direct methods and refined to an R‐factor of 0.036 for the 2606 observed data. The internuclear distances were calculated between the two oxygen atoms and N(1) for comparison with such “triangulation” data of other systems with known inhibitory characteristics of cell growth.
Synthesis of quinoxaline derivatives through condensation of 1,2‐diaminobenzenes with β‐keto sulfoxides
Authors: Kano Shinzo , Shibuya Shiroshi , Yuasa Yoko 
Published: March 2009

AbstractThe reaction of o‐phenylenediamine with α‐methylsulfinylcyclohexanone and α‐methylsulfinylcyclopentanone in the presence of acetic acid afforded 1,2,3,4‐tetrahydrophenazine and 2,3‐dihydro‐1H‐cyclopenta[b]‐quinoxaline, respectively. 3,4‐Diaminotoluene and 3,4‐diaminochlorobenzene were reacted with α‐methyl‐sulfinylacetophenone to give a mixture of the corresponding 6‐ and 7‐substituted 2‐phenylquinoxaline. Condensation of 3,4‐diaminomethoxybenzene with α‐methylsulfinylacetophenone gave 7‐methoxy‐2‐phenylacetophenone, whereas, the same reaction between 3,4‐diaminonitrobenzene and α‐methylsulfinylacetophenone yielded 6‐nitro‐2‐phenylquinoxaline.
Reversible cyclization of N‐(3‐hydroxy‐1‐alkenyl)pyridinium salts to pyridooxazines
Authors: Carotti A. , Casini G. , Ferappi M. , Cingolani G. M. 
Published: March 2009

AbstractPartially hydrogenated pyrido[2,1‐b][1,3]oxazine, cyclopenta[d]pyrido[2,1‐b][1,3]oxazine and pyrido[1,2‐a]‐[3,1]benzoxazine ring systems were easily formed in the reaction of 3‐hydroxy‐2‐(2‐hydroxy‐1,3‐dioxo‐2‐indanyl)‐2‐alken‐1‐one derivatives with tosyl chloride and pyridine bases. A facile interconversion between pyridooxazines and the corresponding pyridinium salts was also realized.
A synthesis of some novel 4,5‐dihydroazepines by the reaction of oxazolium 5‐oxides with 1,2‐dicyanocyclobutene
Authors: Turchi Ignatius J. , Maryanoff Cynthia A. , Mastrocola Antonietta R. 
Published: March 2009

AbstractHeating primary or secondary α‐amino acids in acetic anhydride in the presence of 1,2‐dicyanocyclobutene leads to 4,5‐dihydroazepines via the intermediacy of mesoionic oxazolium 5‐oxides.
Reactions of ethyl cinnamates with arylacetamides
Authors: Shandala Mowafak Y. , Al‐Khashab Abdul‐Ilah Y. , Afzal M. , Ahmad Shakir S. 
Published: March 2009

AbstractReactions of ethyl cinnamates with arylacetamides gave the corresponding 2,6‐diketo‐3,4‐diarylpiperidine (1a‐o) in addition to the corresponding cinnamides (2a‐o) and arylacetates (3a‐o). The latter two are formed from the intermediates of the Claisen condensation of the reactants. On the other hand and contrary to the above results, condensation of p‐methoxycinnamate with arylacetamides gave only p‐methoxycinnamide in quantitative yields with the corresponding arylacetates.
Derivatives of perhydrofuro[2,3‐c]pyridin‐2‐one
Authors: Borne Ronald F. , Aboul‐Enein Hassan Y. 
Published: March 2009

AbstractSynthetic approaches to the preparation of perhydrofuro[2,3‐c]pyridin‐2‐one derivatives as analogs of pilocarpine are reported. Derivatives of the desired ring system were obtained from iodolactonization of the appropriate tetrahydropyridyl esters.
Spectroscopic evidence for the intermediacy of a 6‐R‐2,4‐diazabicyclo‐[3.1.0]hex‐2‐(3)ene in the photoisomerization of 4‐R‐1,4‐(3,4)‐dihydropyrimidines
Authors: Van Der Stoel R. E. , Van Der Plas H. C. , Geurtsen G. 
Published: March 2009

Abstract1H‐ and 13C‐nmr spectroscopy is presented showing that photolysis of 4‐(p‐trifluoromethylphenyl)‐1,4‐(3,4)‐dihydropyrimidine yields 6‐(p‐trifluoromethylphenyl)‐2,4‐diazabicyclo[3.1.0]hex‐2‐(3)ene.
Alkaline hydrolysis of 3‐methyl‐4‐nitro‐5‐styrylisoxazole with Na18OH
Authors: Sarti‐Fantoni P. , Donati D. , De Sio F. , Moneti G. 
Published: March 2009

AbstractThe use of enriched Na18OH in the hydrolysis of 3‐methyl‐4‐nitro‐5‐styrylisoxazole leads to oxygen‐labelled cinnamic acids. Isoxazole ring opening and cleavage of title compound has been investigated.
Peptide sequencing with the 2‐pyridinecarboxaldehyde schiff base peptide degradation
Authors: Day R. A. , Jayasimhulu K. , Evans J. V. , Bhat G. , Lin L. C. , Wieser M. J. 
Published: March 2009

AbstractDedicated to Professor John C. Sheehan on the occasion of his sixty‐fifth birthday.Peptides treated with 2‐pyridinecarboxaldehyde are converted to Schiff bases, pyridoimidazoles, α‐ketoacyl amino acids and peptide amides, and diketopiperazines. Nitrogen abstraction and condensation with 2‐pyridinecarboxaldehyde gives heterocyclic products. The products are separable by gas chromatography and when analyzed by mass spectrometry afford information for sequence assignment. Thus, a nonvolatile peptide can be converted to a mixture of products in one step that by mass spectrometric analysis affords the sequence. Peptides of up to eight and nine amino acids have been analyzed using this degradation as the basis of a one‐step procedure.
Synthesis of 2‐amino‐3‐benzoylphenylacetic acid
Authors: Lo Young S. , Walsh David A. , Welstead William J. , Mays Richard P. , Rose Edward K. , Causey David H. , Duncan Robert L. 
Published: March 2009

Abstract2‐Amino‐3‐benzoylphenylacetic acid, sodium salt was prepared from indoline through a process applicable to large scale production.
Recherche en série du triazole‐1,2,4. II‐Réactivité des amino‐4 aryl‐3 triazol‐1,2,4 ones‐5
Authors: Milcent René , Redeuilh Catherine 
Published: March 2009

AbstractLa Nl‐alkylation, les acylations sélectives, les réactions de condensation et diverses oxydations de l'amino‐4 phényl‐3 triazol‐1,2,4 one‐5 sont présentées. Elles permettent la synthése de nombreux composés nouveaux parmi lesquels les diaryl‐2,4 oxa‐1 tetraaza‐3,3a,5,6 pentalénes.
Natural benzofurans. Synthesis of medicagol methoxybenzofuran
Authors: Scannell Ralph T. , Stevenson Robert 
Published: March 2009

AbstractA general route to 2‐arylbenzofurans, consisting of reaction of an o‐halogenophenol ester with a cuprous arylacetylide, was employed to synthesize medicagol methoxybenzofuran. 2,4‐Diraethoxyacetophenone was converted to 2,4‐dimethoxyphenylacetylene in three steps and reaction of the cuprous salt with 2‐iodo‐4,5‐methylenedioxyphenyl acetate gave the desired 2‐(2′,4′‐dimethoxyphenyl)‐5,6‐methylenedioxybenzofuran.
Rearrangement of 4‐aryl‐1,2,4‐triazine into the 4‐amino derivatives
Authors: Ibrahim Yehia A. , Eid M. M. , Abdel‐Hady S. A. L. 
Published: March 2009

AbstractThe action of hydrazine on 3‐methylmercapto‐5‐oxo‐4‐aryl‐4,5‐dihydro‐1,2,4‐triazines led to a novel rearrangement and gave 3‐arylamino‐4‐amino‐5‐oxo‐4,5‐dihydro‐1,2,4‐triazines. The mechanism of this rearrangement was discussed.
The synthetic utility of heteroaromatic azido compounds. Part VII. Preparation of some 2‐ and 4‐substituted thieno[3,2‐d]pyrimidines
Authors: Westerlund Christer 
Published: March 2009

AbstractSynthetically useful scission reactions of some 1H‐1,2,3‐triazolo[1,5‐a]thieno[3,2‐d]pyrimidines have been studied. The net result of these reactions is an elimination of nitrogen, and a 1,1‐addition of the cleaving agent, forming 2‐substituted thieno[3,2‐d]pyrimidines. The mechanism of the scission is discussed, and a concomitant nucleophilic attack and expulsion of nitrogen is proposed. An unusual reaction between the unsubstituted triazole‐fused parent compound (1) and bromine in alkaline medium is also reported.
Photoaddition of ketones to imidazoles, thiazoles, isothiazoles and isoxazoles. Synthesis of their oxetanes
Authors: Nakano Tatsuhiko , Rodríguez Wilma , De Roche Severina Z. , Larrauri José M. , Rivas Carlos , Pérez Carmen 
Published: March 2009

AbstractImidazole itself did not undergo photoaddition reactions with ketones. However, irradiation of 1‐acetyl and 1‐benzoylimidazole, and 1,1‐carbonyldiimidazole with benzophenone yielded oxetanes. On irradiation with carbonyl compounds, 1,2‐dimethylimidazole and 1‐benzylimidazole did not give oxetanes but a hydroxyaryl or hydroxyalkyl derivative. Thiazole itself did not yield any photoaddition product, but 2,4‐dimethylthiazole afforded oxetanes on irradiation with benzophenone and with 3‐benzoylpyridine. Irradiation of 2,4‐dimethylthiazole with acetophenone led to the formation of a dimeric material. On irradiation with benzophenone, 4‐methylisothiazole did not yield an oxetane but rather a hydroxyphenyl derivative. 3,5‐Dimethylisoxazole on irradiation with benzophenone and with 3‐benzoylpyridine gave oxetanes. Irradiation of 4,5‐dimethylisoxazole yielded similarly an oxetane with benzophenone
A novel tetracyclic ring system. 10H‐tetrazolo[5′,1′:3,4][1,2,4]triazino[5,6‐b]indole
Authors: Joshi Krishna C. , Chand Pooran 
Published: March 2009

AbstractThe reaction of 3‐hydrazino‐1,2,4‐triazino[5,6‐b]indole with nitrous acid affords a novel tetracyclic ring system: 10H‐tetrazolo[5′,1′:3,4][1,2,4]triazino[5,6‐b]indole. The mode of cyclization has been discussed.
Cyclic peptides from penicillium islandicum. A review and a reevaluation of the structure of islanditoxin
Authors: Ghosh Anil C. , Ramgopal Malathi 
Published: March 2009

AbstractDedicated to Professor John C. Sheehan on the occasion of his sixty‐fifth birthday.The structures of cyclochlorotine and islanditoxin, cyclic peptides from Penicillium islandicum are reviewed. The peptide A isolated in these laboratories has been identified by gc/ms studies as cyclochlorotine. It is suggested that the structure of islanditoxin [cyclo‐(L‐dichloroprolyl‐D‐β‐amino‐β‐phenylpropionyl‐L‐α‐amino‐n‐butyryl‐L‐seryl‐L‐serine)] 1 should now be revised to that of cyclochlorotine, [cyclo‐(L‐dichloroprolyl‐D‐β‐amino‐n‐butyryl‐L‐seryl‐L‐β‐amino‐β‐phenyl‐propionyl‐L‐serine)] 2.
Chiral environments for asymmetric hydrogenation of model didehydro‐amino acid residues
Authors: Davies John S. , Eaton Mark C. , Ibrahim M. Nazar 
Published: March 2009

AbstractDedicated to Professor John C. Sheehan on the occasion of his sixty‐fifth birthdayNmr and glc analysis of diastereoisomeric mixtures of dipeptides has been used to study the asymmetric hydrogenation of model benzoyldidehydro‐ and trifluoroacetyldidehydro‐dipeptide methyl esters. Chiral enhancement of one isomeric form appears to be independent of the N‐terminal acyl group, but is significantly influenced by the choice of amino‐acid in the C‐terminal position. C‐Terminal aromatic amino‐acids and their derivatives give the best chiral enhancement during hydrogenation of a neighbouring dehydroamino‐acid residue.
Synthesis of some N‐heteroaromatic analogues of cannabinoids
Authors: Chiodini Laura , Di Ciommo Mauro , Merlini Lucio 
Published: March 2009

AbstractThe synthesis of some [1]benzopyrano[3,4‐b]pyrazine, ‐[3,4‐d]imidazole, ‐[4,3‐c]imidazole, ‐[4,3‐c]pyrazole and ‐[3,4‐d]isoxazole analogues of cannabinoids is reported.
Synthesis of 2‐S‐dioxo isosteres of purine and pyrimidine nucleosides. I. Alkyl and glycosyl derivatives of 3,5‐diamino‐4H‐1,2,6‐thiadiazine 1,1‐dioxide
Authors: Resa P. Fernández , Stud M. 
Published: March 2009

AbstractPreparation of alkyl and glycosyl derivatives of 3,5‐diamino‐4H‐1,2,6‐thiadiazine 1,1‐dioxide (1) is described. Reaction of 1 with dimethyl sulfate gave the 4‐methyl and 2,4‐dimethyl derivatives. With benzyl chloride and allyl bromide C‐4 substituted compounds were obtained. Reaction of the disilyl derivative of 1 with either 2,3,4,6‐tetra‐O‐acetyl‐α‐D‐glucopyranosyl bromide or 1,2,3,4,6‐penta‐O‐acetyl‐β‐D‐glucopyranose in the presence of Friedel‐Crafts catalysts afforded the α and β anomers of the N‐2 nucleoside and the β‐O‐glucoside. When the reaction was performed with 1‐O‐acetyl‐2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranose, a β‐C‐glycoside and the α and β anomers of the N‐2 nucleoside were obtained. The structure of the corresponding nucleosides were elucidated by 1H nmr and uv by comparing the latter with those of the alkyl derivatives.
Synthesis of 2,4‐substituted 6,7‐phenanthreno‐and 6,7‐acenaphthenopteridines
Authors: Ram Vishnu J. , Pandey Hrishi Kesh , Vlietinck Arnold J. 
Published: March 2009

AbstractA series of 6,7‐phenanthreno‐ and 6,7‐acenaphthenopteridines bearing different substituents at positions 2 and 4 are prepared. The structures of the compounds are confirmed by spectroscopic studies and elemental analyses.
Synthesis and reactions of 2‐chloro‐3,4‐dihydrothienopyrimidines and ‐quinazolines
Authors: Yamaguchi Hitoshi , Ishikawa Fumiyoshi 
Published: March 2009

AbstractReaction of 2,4‐dichlorothienopyrimidines and ‐quinazolines 1 with sodium borohydride gave the corresponding 2‐chloro‐3,4‐dihydro derivatives 2. Some nucleophilic substitutions of 2b afforded 2‐substituted derivatives 3b‐7b and reaction of 2g,h with ethyl bromoacetate yielded selectively the corresponding 3‐substituted compounds 8g,h which were derived to imidazo[2,1‐b]quinazolin‐2‐ones 9g,h.
Mass spectra of substituted Δ2‐1,2,4‐oxadiazolines. II
Authors: De Albuquerque Julianna F. C. , Srivastava R. M. 
Published: March 2009

Abstract5,5‐Pentamethylene‐3‐(phenyl or para‐substituted‐phenyl)‐Δ2‐1,2,4‐oxadiazolines, 1a‐e, were examined by electron‐impact mass spectrometry. Defocussed metastable ion detections confirmed the formation of certain daughter fragments from the mother ions. The exact mass measurements helped to make the correct assignment of various species. We conclude that it is the spiro arrangement which caused such a dramatic change in the decomposition pattern. Several new fragmentation pathways have been found in the present studies. Out of five oxadiazolines prepared for the present work, three (1b,d,e) are new.
Reaction of some coumarin and 4,6‐diaryl‐2H‐pyran derivatives with secondary amines
Authors: El‐Kholy Ibrahim El‐Sayed , Mishrikey Morcos Michael , Feid‐Allah Hassan Mostafa 
Published: March 2009

AbstractThe reaction of piperidine, morpholine, piperazine or dimethylamine with several coumarins, 3‐bromocoumarin, 4,6‐diaryl‐2H‐pyran‐2‐ones and 3‐bromo‐4,6‐diaryl‐2H‐thiopyran‐2‐ones gave o‐hydroxycinnamic acid amides, benzofurans, open‐chain δ‐oxoamides and thiophene derivatives, respectively.
Reaction of ethyl 3‐ethoxymethylene‐2,4‐dioxovalerate and ethyl ethoxymethyleneoxaloacetate with 3‐aminopyrazole analogs. Synthesis and chemistry of 3,6,7‐trisubstituted pyrazolo[1,5‐a]pyrimidine derivatives
Authors: Kurihara Takushi , Nasu Keiko , Ishimori Fumiko , Tani Tsutomu 
Published: March 2009

AbstractThe chemical reactivity of a series of 3‐substituted‐6‐acetyl‐7‐carbethoxypyrazolo[l,5‐a]pyrimidines (6a,b,c) and 3‐substituted‐6,7‐dicarbethoxypyrazolo[1,5‐a]pyrimidines (7a,b,c), prepared by the condensations of the 3‐aminopyrazole analogs (3a,b,c) with ethyl 3‐ethoxymethylene‐2,4‐dioxovalerate (1) or ethyl 3‐ethoxymethyleneoxaloacetate (2), was investigated. Catalytic hydrogenation of 6 or 7 afforded 4,7‐dihydro derivatives (8 or 9). Treatment of 6a,b with acetic acid and water underwent ring transformation into 6H‐pyrazolo[1,5‐a][1,3]diazepin‐6‐ones (17a,b). By treatment with phenylhydrazine compounds of type 6 underwent cyclization to yield 2H‐dipyrazolo[1,5‐a:4′,3′‐e]pyrimidines (18a,b,c). Compounds 6 or 7 were treated with an excess of diazomethane at room temperature to give 5‐methyl‐6H‐cyclopropa[5a,6a]pyrazolo‐[1,5‐a]pyrimidines (24 and 25) in excellent yields. However, when this reaction was carried out under ice cooling, only compounds of type 23 were isolated. Reaction of 6a with ethyl diazoacetate is also described.