bluuebunny/crossref_metadata_2025_split huggingface dataset:
1,2‐ and 1,4‐Diacetoxylation of 1,3‐butadiene via 2,5‐dihydrothiophene 1,1‐dioxide as a probable intermediate
Authors: Tempesti E. , Giuffrè L. 
Published: April 2009

AbstractSulphur dioxide has been found to promote a novel liquid‐phase oxidation of 1,3‐butadiene in acetic anhydride with oxygen gas and catalytic amounts of concentrated protic acids (e.g. hydrobromic acid). 1,2‐Diacetoxy‐3‐butene and 1,4‐diacetoxy‐2‐butene together with small amounts of 1‐hydroxy‐2‐acetoxy‐3‐butene and 1‐hydroxy‐4‐acetoxy‐2‐butene are formed in the reaction.
Derivatives of 2,4‐diamino‐6‐methylpteridine
Authors: Montgomery John A. , Piper James R. , Elliott Robert D. , Roberts Eugene C. , Temple Carroll , Shealy Y. Fulmer 
Published: April 2009

AbstractEighteen derivatives of 2,4‐diamino‐6‐methylpteridine related to methotrexate and aminopterin have been prepared from 6‐(bromomethyl)‐2,4‐pteridinediamine by nucleophilic displacement reactions. None of these compounds showed any antileukemic acitivity.
1,2,4‐Triazines. Synthesis of selected members of the s‐triazolo[3,4‐f]‐ [1,2,4] triazine and tetrazolo[1,5‐f] [1,2,4] triazine ring systems
Authors: Lovelette Charles A. 
Published: April 2009

AbstractA convenient synthesis of 3‐amino‐6‐hydrazino‐5(2H)[1,2,4]triazinone 4 has been developed and a study of the reactions of 4 with aliphatic acids, orthoesters and miscellaneous active carbonyl reagents has been undertaken. When 4 was refluxed in either neat acid or orthoester in dimethylformamide, a facile ring closure reaction with the N‐1 nitrogen of the 1,2,4‐triazine ring occurs affording a novel series of 3‐aIkyl(aryl)‐8(5H)‐s‐triazolo[3,4‐f] [1,2,4]triazinones (6–11). Ring closure with carbon disulfide and cyanogen bromide is also reported affording 6‐amino‐3(2H)thio‐8(5H)‐s‐triazolo[3,4‐f] [1,2,4]triazinone 12 and 3,6‐diamino‐8(5H)‐s‐triazolo‐[3,4‐f] [1,2,4]triazinone 14, respectively. In addition 4 has been converted into 3‐amino‐6‐azido‐5(2H)‐1,2,4‐triazinone 15 which was employed in a study of azide‐tetrazole equilibrium affording 6‐amino‐8(5H)tetrazolo[1,5‐f][1,2,4]triazinone 16. Rates for interconversion at various temperatures were measured and an activation energy for the process determined.
Synthesis of 5‐(3,4,5‐trimethoxyphenyl)‐4‐substituted aryl‐3‐hydrazino‐carbonylmethylthio‐4H‐1,2,4‐triazoles as possible antiinflammatory agents
Authors: Jaiswal Rama K. , Parmar Surendra S. , Singh Shiva P. , Barthwal Jayanti P. 
Published: April 2009

AbstractA series of 5‐(3,4,5‐trimethoxyphenyl)‐4‐substituted aryl‐3‐hydrazinocarbonylmethylthio‐4H‐1,2,4‐triazoles were synthesized and evaluated for their antiprotolytic and antiinflammatory activities.
Dipole moments. Structure and conformation of asymmetrically 4,5‐substituted 1‐(α‐aroyloxyarylideneamino)‐1,2,3‐triazoles
Authors: Rodios N. A. , Alexandrou N. E. 
Published: April 2009

AbstractThe dipole moments of several asymmetrically 4,5‐substituted 1‐(α‐aroyloxyarilideneamino)‐1,2,3‐triazoles, produced by oxidation of bis‐aroylhydrazones of α‐dicarbonyl compounds, were measured in benzene solution. The structure and the probable conformation of each of these compounds was determined by comparing their experimental and theoretical dipole moments. It has been found that when one of the substituents R1 or R2 is an aryl group, it is located at the 4‐position of the triazole ring. Considering the conformation of the ester‐imino function, it has been found to be the same as that of symmetrically substituted derivatives.
A new route for the preparation of pyrazolo[3,4‐c] pyridines
Authors: Migliara Onofrio , Petruso Salvatore , Sprio Vincenzo 
Published: April 2009

AbstractCatalytic reduction of the oximes of 4‐phenacyl‐3(5)R‐pyrazole‐4‐carboxylic acid esters (4a,b) followed by cyclisalion constitutes a new appraoch to substituted pyrazolo[3,4‐c]pyridines. The starting materials 4a,b were prepared by reaction of ω‐bromoacetophenone oxime and sodium salts of oxalyl derivatives 2a,b and successive action of hydrazine on the obtained products 3a,b. Structural assignments rested upon correct elemental analysis and spectroscopic evidences.
Studies on the synthesis of analgesics. Part 51. Synthesis of 4‐(1‐oxo‐2‐isoindolinyl)phenyl derivatives. [Studies on the syntheses of heterocyclic compounds. Part 779]
Authors: Kametani Tetsuji , Kigasawa Kazuo , Hiiragi Mineharu , Ishimaru Haruhide , Nakamura Toshihisa , Shirayama Keiko 
Published: April 2009

AbstractIn order to examine their effect on carrageenin‐induced edema in rats, 4‐(1‐oxo‐2‐isoindolinyl)‐phenyl derivatives were synthesized. 2‐Hydroxy‐3‐[4‐(1‐oxo‐2‐isoindolinyl)phenyl]butyramide was found to be more effective than phenylbutazone.
Chiroptical properties of cyclic amines
Authors: Bettoni Giancarlo , Morlacchi Flaviano , Perrone Roberto , Tortorella Vicenzo , Vetuschi Claudio 
Published: April 2009

AbstractChiroptical properties of several 2 or 3 monosubstituted azetidines, pyrrolidines and piperidines as free bases and N‐[2‐pyridyl N‐oxide] derivatives has been examined. The absolute configuration can be unambiguously established, independently on the nature of the substituent and the size of the ring, only for 2‐substituted N‐[2‐pyridyl N‐oxide]amine derivatives. This behaviour is explained in terms of limited rotational freedom in these compounds.
2,3,5,6‐Tetramethylmorpholine. III. Synthesis of the enantiomeric pair of the β1‐isomer
Authors: Tarn Sven Hemes 
Published: April 2009

AbstractThe cyclodehydration of optically active N‐benzyl‐3,3′‐iminobis‐2‐butanols with sulfuric acid is described. Morpholines with high optical purity are obtained.
Access to 14C‐Ring labelled phenothiazines. Synthesis of 2‐chlorophenolhiazine‐5a,9‐14C
Authors: Muccino Richard R. , Cupano Joseph , Liebman Arnold A. 
Published: April 2009

AbstractThrough the use of a recently reported ring expansion reaction, a new route to phenolhiazines has been developed suitable for the preparation of ring labelled derivatives. As an example, the preparation of 2‐chloropheno thiazine‐5a,9‐14C (1) is reported. Condensation of cyclohexanone‐2‐14C with 2‐amino‐4‐chlorothiophenol gave the spiro‐2,3‐dihydro‐l, 3‐benzothiazole 4 which was protected by acetylation (5). Treatment of 5 with sulfuryl chloride gave the tetrahydro‐phenothiazine olefin mixture 6 and 7 which was directly converted to labelled 1 via treatment with DDQ in refluxing benzene followed by hydrolysis of the acetyl group.
Phenylation of the 5,11‐diazaditwistane nucleus
Authors: Kozlowski Matthew A. , Broeke Jan Ten , Grabowski Eklward J. J. 
Published: April 2009

AbstractA simple phenylation of the 5,11‐diazatetracyclo[6.2.2.02,7 04,9]dodecane system (5,11‐diazaditwistane) is described. Phenylative decarboxylation of 5,11‐biscarbethoxy‐5,11‐diazatetracyclo[6.2.2.02,7 .04,9]dodecane‐2,9‐dicarboxylic acid (3) with lead tetraacetate in benzene affords the 2,9‐diphenyl analogue (4). Hydrolysis yields 2,9‐diphenyl‐5,11‐diazatetracyclo‐[6.2.2.02,7.04,9]dodecane (5), whereas lithium aluminum hydride affords the 5,11‐dimethyl analogue (6).
A convenient and rapid synthesis of potassium penicilliantes using EEDQ
Authors: Voldeng A. Nelson , Fifer Janet T. , Brown D. Ray 
Published: April 2009

AbstractN‐ethoxycarbonyl‐2‐ethoxy‐1,2‐dihydroquinoline (EEDQ, 1) has been utilized as a coupling reagent to attach sterically unhindered acids to the potassium salt of 6‐aminopenicillanic acid (4) at room temperature.The excellent yields and rapidity of the reaction illustrate the convenience of utilizing 1 as the coupling reagent to directly prepare the potassium salt of certain penicillins.
The reaction of epibromohydrin with hydroxyquinazolin‐2‐(1H)one derivatives. Novel oxazine formation
Authors: Cotter Mary Lou , Bandurco Victor , Wong Elizabeth , Hajos Zoltan G. 
Published: April 2009

AbstractEpibromohydrin was found to react with 7‐hydroxy‐2‐methylpyrrolo[1,2‐c]quinazolin‐5(6H)‐one (4) in the presence of sodium hydroxide to form the novel oxazine 5. The structure of compound 5 was proven by cmr and pmr analysis.
7,8‐Dihydro‐5(6H)quinolones. Potential intermediates for the synthesis of pumiliotoxic C
Authors: Bennett Gregory B. , Minor Harold 
Published: April 2009

AbstractAn approach to Pumiliotoxin C(1) based on stereoselective hydrogenation of the regioselective condensation products of primary and tertiary vinylogous amides, 7,8‐dihydro‐5(6H)quinolones, is described. The 2‐substituted quinolones fail to undergo complete saturation to the corresponding decahydroquinolines, stopping instead at the hexahydroquinoline oxidation state.
Acylation of heteroaromatic amines. II dibenzoylation of aminopyridines
Authors: Suzuki Toshinobu , Kenbou Naoya , Mitsuhashi Keiryo 
Published: April 2009

AbstractThree isomeric aminopyridines were reacted with an excess of benzoyl chloride in the presence of an excess of triethylamine, giving the corresponding dibenzoylaminopyridines in high yields. As an application of the dibenzoylation, the aminopyridines were also reacted with phthaloyl dichloride, resulting in appreciable yields of the respective N‐pyridylphthalimides. The rate of the conversion under various conditions was studied with high pressure liquid chromatography in order to investigate the difference in reactivity among the three isomers.
2‐Indolyl ketone synthesis
Authors: Unangst Paul C. , Brown Richard E. , Fabian Arthur , Fontseré Frank 
Published: April 2009

AbstractThe preparation of 2‐indolyl alkyl ketones by reductive cleavage of a β‐keto sulfone or by the reaction of 1‐chloro‐2‐propanone (chloroacetone) with a 2‐aminobenzoic acid derivative is described. The β‐keto sulfone intermediates are prepared by condensation of the carbanion of dimethyl sulfone and indole‐2‐carboxylic acid esters. Lack of reactivity of several 2‐aminobenzoic acids in the 1‐chloro‐2‐propanone process is related to the presence of electron‐withdrawing substituents in the aromatic ring.
Optically active heteroaromatic compounds IX. Preparation, absolute configuration and optical purity of some chiral 3‐alkylindoles
Authors: Menicagli Rita , Malanga Corrado , Lardicci Luciano 
Published: April 2009

AbstractThe Fischer and Brunner reactions as well as the Grignard alkylation of isatin have been used to prepare (S)‐3‐sec‐butyl‐ and (S)‐3‐(2‐methylbutyl)indoles, respectively, starting from (S)‐1‐chloro‐2‐methylbutane. The stereospecificity of the synthetic sequences followed has been investigated and the stereochemical relationships of the title compounds have been established.
Synthesis and crystal structure of a covalently hydrated 8‐thia‐1,4‐diazacycl[3.3.2]azine
Authors: Campaigne E. , Huffman J. C. , Selby T. P. 
Published: April 2009

AbstractCondensation of ethyl 4‐chloroacetoacetate with 4‐amino‐6‐hydroxy‐2‐pyrimidinethiol produced ethyl 3‐hydroxy‐5‐amino‐7‐oxothiazolino[3,2‐a]pyrimidin‐3‐acetate (7a) on crystallization. Subsequent ring closure of 7a produced the tricyclic 6a‐hydroxy‐5,6,6a,7‐tetrahydro‐8‐thia‐1,4‐diazacycl[3.3.2]azin‐2,5‐dione (8). The structure of 8 was confirmed by crystal x‐ray diffraction analysis.
Studies on the chemistry of pharmacologically active heterocycles. Part I. Acid hydrolysis of hydrazino‐1,2,4‐triazine derivatives
Authors: Daneshtalab M. , Khalaj A. , Lalezari I. 
Published: April 2009

AbstractThe acid hydrolysis of 3‐hydrazino‐5,6‐disubstituted‐1,2,4‐triazine, 3,5‐dihydrazino‐6‐substituted‐1,2,4‐triazine, and 2‐hydrazinopyrimidine derivatives was studied. It was found that the reaction proceeded through the formation of 3‐keto and 3,5‐diketo derivatives of the related 2,3‐dihydro, 2,3,4,5‐tetrahydro‐1,2,4‐triazines, and 2‐keto derivatives of 1,2‐dihydropyrimidines. It was concluded from these reactions that in 1,2,4‐triazine derivatives the C‐5 carbon is more reactive than the C‐3 carbon toward nucleophiles. The reaction mechanism is discussed.
Uber die reaktionen der 1,4,7‐triketone mit hydrazin
Authors: Stetter Hermann , Landscheidt Alfons 
Published: April 2009

AbstractAus 1,4,7‐Triketonen und Hydrazin entstehen je nach den Reaktionsbedingungen Dihydro‐pyridazinhydrazone 1–8 oder Dihydropyrrolo [1,2‐b]pyridazine 9–19. Letztere werden durch Chloranil zu den Pyrrolo[1,2‐b] pyridazinen 20–23 dehydriert.
The reaction of cationic dyes with disodium cromoglycate
Authors: Spilzer J. C. , Wolff D. A. 
Published: April 2009

AbstractThe reaction of disodium cromoglycale with five cationic dyes: crystal violet, Janus green, methylene blue, methyl green, and safranine, was investigated. Spectroscopic shifts indicated that at low concentration (0.01 mM) all these dyes were able to form complexes (ion paris) with the cromoglycale anion. In addition, the complexes formed by crystal violet and Janus green were extractable into chloroform.
Novel heterocycles. 3. Synthesis of fused 1,3,2‐benzodiazaphosphorin ring systems
Authors: Coppola Gary M. 
Published: April 2009

AbstractNovel fused tricyclic phosphorus heterocycles 9 and 11 and the tetracycle 15 were synthesized by cyclization of 1‐haloalkyl (or 3‐haloalkyl)‐2,3‐dihydro‐1,3,2‐benzodiazaphosphorin‐4(1H)one 2‐oxides with sodium hydride. Some spectral data of the products are also discussed.
Alkylation studies on 6‐ethyl‐2,3‐dihydrothiazolo‐[3,2‐A] pyrimidine‐5,7‐diones
Authors: Glennon Richard A. , Bass R. G. , Schubert E. 
Published: April 2009

AbstractThe title compound 7b undergoes alkylation with ethyl iodide or ethyl sulfate at the 7‐position yielding the O‐ethylated product 10 rather than 6,6‐diethyl product 8 as reported previously. Reaction of 7b with mesyl chloride gives 13b which on reaction with potassium carbonate in absolute ethanol also gives 10. Treatment of 7b with phosphorus oxychloride gives 11b which on reaction with potassium carbonate or sodium ethoxide in ethanol produced a mixture from which no 10 was isolated. Authentic 8 was prepared by the reaction of 2‐amino‐thiazoline with ethyl diethylmalonyl chloride (20) in THF containing triethylamine or by the reaction of 5,5‐diethyl‐2‐thiouracil (18) with excess 1,2‐dibromoethane.
Synthesis of 2‐(o‐chloropheny)‐ and 2‐(2′,6′‐dichlorophenyl)‐4‐formyl‐1,2,3‐triazoles
Authors: Swartz David L. , El Khadem Hassan S. 
Published: April 2009

AbstractMesoaldehyde 1,3‐dioxime was treated with either o‐chlorophenyl‐ or 2,6 dichloro‐phenylhydrazine to give the corresponding 2‐chlorophenylhydrazone. Hydrazones 1a and 1b were treated with acetic anhydride and cyclized to triazoles (3a and 6a) with cesium carbonate. These were then hydrolized to the previously unknown chlorophenyltriazole aldehydes (4a and 4b). They were also converted to a number of acid derivatives, alcohols, and amines.
The thermal rearrangement of thiabenzenes to their isomeric thiopyrans
Authors: Pirelahi Hooshang , Haghgooii Housane 
Published: April 2009

AbstractThe rates of rearrangement in 1‐phenyl‐2,4,6‐tris(p‐methoxyphenyl)thiabenzene (4) and 1‐(p‐tri‐fluoromethylphenyl)‐2,4,6‐triphenylthiabenzene (5) were determined and a crossover experiment was carried out with a mixture of these thiabenzenes. The possibility of 2,4‐migrations in the thiopyran system under the reaction conditions was also studied by examining two samples of thiopyrans. The results indicate an intramolecular rearrangement which involves a 1,2‐ and 1,4‐migration of 5‐aryl groups in thiabenzenes.
Studies on the synthesis of heterocyclic compounds. III. Preparation of some pyrazolo[3,4‐C] [1,5]benzodiazocin‐10(11H)one derivatives
Authors: Plescia Salvatore , Daidone Guiseppe , Sprio Vincenzo 
Published: April 2009

AbstractStarting from the readly available N‐melhyl‐N‐(1‐phenyl‐3‐R‐pyrazol‐5‐yl)‐2‐nitrobenzamides (1a,b), the pyrazoles, 4‐aeetyl substituted 2a,b, were prepared in high yield. Reduction of 2a gave the amino derivative 4a, which was eyclized to the desired pyrazolo[3,4‐c][1,5]benzodiazo‐cin‐10(11H)one (5a). Compound 2b afforded 5b directly. Compound 5b was also prepared by the action of phosphorus oxychloride on N‐methyl‐N‐(1,3‐diphenylpyrazol‐5‐yl)‐2‐acetamido‐benzamide (6b).
Recherches dans la serie des hydroindolizines fonctionnelles
Authors: Céaléarier Jean‐Pierre , Eskéanazi Christian , Lhornmet Gerard , Maitte Pierre 
Published: April 2009

AbstractDans eet article sont décrites des voies d'accès commodes et généralisables de dérivés de l'indulizine possédant deux fonctions réactives sur les carbones 7 et 8 ou 5 et 8.
Action des réartif's électrophiles sur les hydroxy‐3 thiadiazoles‐1,2,4
Authors: Taliani Laurent , Pcrronnet Jacques 
Published: April 2009

AbstractLes réaetifs électrophiles peuvent se fixer sur l'atome d'oxvgène de l'hydroxyle en 3 on sur I'atome d'azote 2 des hydroxy‐3 thiadiazoles‐1,2,4 (1). Les réactifs qu'on peut considérer comme “durs” (chlorures d'acides) conduisent en prépondérance an premier type de dérivés, 2. Les isocyanates et anhydrides d'acides qui fournissent exclusivement des dérivés du second type, 3, se comportent comme des réaetifs “mous”.
Stereoselective synthesis of substituted piperazines
Authors: Barluenga J. , Nájera C. , Yus M. 
Published: April 2009

AbstractThe treatment of allylarylamines with mercury(II) acetate in tetrahydrofuran followed by a double decomposition reaction with potassium bromide leads to trans‐2,5‐bis(bromomercuriomethyl)‐1,4‐diarylpiperazines (2). The stereochemistry of the reaction products has been elucidated by an 1H‐nmr spectroscopic study of the trans‐2,5‐dimethyl‐1,4‐diarylpiperazines (3) obtained by sodium borohydride reduction of 2 in alkaline media. The course of the reaction strongly depends on the steric demand of the groups attached to either the allylic group or the ortho‐position in the aromatic ring of the starting amine (1).
13C nmr assignments of selected octahydroindolizines
Authors: Sonnet Philip E. , Netzel Daniel A. , Mendoza Robert 
Published: April 2009

AbstractSeveral octahydroindolizines including the four geometrical isomers of 3‐butyl‐5‐methyloctahydroindolizine, which is an attractant of Pharaoh's and [Monomorium pharaonis(L.)], have been examined by 1H and 13C nmr spectroscopy. The conformations of these compounds are discussed.
Synthesis of 5‐methylmercaptopyrimidine nucleosides
Authors: Ryu E. K. , Bardos T. J. 
Published: April 2009

AbstractThe synthesis of a series of new nucleosides, including ribo‐, 2′‐deoxyribo‐ and arabinofuranosides of 5‐(S‐methyl)mercapto‐substituted uracil, 4‐thiouracil, and cytosine is described. The synthetic methods employed include condensation reactions of the silylated pyrimidine with blocked sugar halides, as well as transformations of both the base and sugar moieties. The separated α and β anomers were identified by nmr spectra as well as by unambiguous synthetic routes or interconversions.
Meso‐ionic compounds. XI, photochromic 4‐halogeno‐3‐(3‐pyridyl)sydnones
Authors: Greco Claude V. , Mehta Jitendra R. 
Published: April 2009

AbstractHalogenation of 3‐(3‐pyridyl)sydnone with N‐halosuccinimides in chloroform afforded the 4‐halogeno‐3‐(3‐pyridyl)sydnones where X = CI, Br, I. The 4‐chloro‐ and 4‐bromopyridylsydnones were photochromic. 3‐(3‐Pyridyl)sydnone was obtained in both high yield and purity by dehydration of N‐nitroso‐N‐(3‐pyridyl)glycine with trifluoroacetic anhydride.
Synthesis and thermochemical behaviour of 1H‐1,2‐benzodiazepine‐3‐carboxylic acids
Authors: Garanti Luisa , Zecchi Gaetano 
Published: April 2009

AbstractThe title earboxylic acids, prepared by alkaline hydrolysis of their ethyl esters, thermally decomposed to give ortho‐aminocinnamonitriles and, in few cases, 3‐unsubstituted 1H‐1,2‐benzodiazepines.
3H‐2,1,3‐benzolhiadiazine 2,2‐dioxide. A novel heterocyclic system
Authors: Pews R. G. 
Published: April 2009

AbstractA new heterocyclic system, 3H‐2,1,3‐benzothiadiazine 2,2‐dioxide has been prepared via oxidation of the 3,4‐dihydro‐1H‐2,1, 3‐benzothiadiazine 2,2‐dioxides.
An improved synthesis of 2,4,8,10‐tetroxaspiro[5.5]undeeane (pentaerythritol diformal)
Authors: Poshkus Algirdas C. 
Published: April 2009

AbstractPentaerythritol diformal is prepared almost quantitatively in less than ten minutes by heating up to about 120° a neat mixture of pentaerythritol with a slight excess of paraformaldehyde containing catalytic amounts of a mineral acid.
Heterocycles. 7. A facile synthesis of 6,7‐dihydroxs‐1,4‐dithiepins
Authors: Weintraub Philip M. 
Published: April 2009

AbstractRing expansion by dehydration of 1,3‐dithian‐2‐ylmethanols gives 6,7‐dihydro‐5H‐1,4‐dithiepins.
The synthesis of 5‐azaindole derivatives via mesoionic oxazolium 5‐oxides
Authors: Hershenson Fred M. 
Published: April 2009

AbstractA synthesis of 5‐azaindole derivatives is described. This synthetic approach involves the preparation of an appropriately substituted pyrrole derivative by a 1,3‐dipolar cycloaddition reaction of dimethyl acetylenedicarboxylate with a mesoionic oxazolium 5‐oxide. The pyrrole intermediate contains a protected β‐aminoethyl substituent, and subsequent removal of the phthalimido protecting group results in cyclization to yield the corresponding 5‐azaindole. This approach has been used for both acyclic and cyclic amino acid precursors of the 1,3‐dipole which is ultimately used in the sequence.
Studies on heterocyclic primary amines, I. reaction of 2‐amino‐5‐aryl‐1,3,4‐oxadiazoles with phosphorus pentachloride
Authors: El‐Deek M. , El‐Badry K. , Abdel‐Wahhab S. M. 
Published: April 2009

AbstractStable N‐(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)phosphorimidic trichlorides (II) are obtained by refluxing 2‐amino‐5‐aryl‐1,3,4‐oxadiazoles (I) with one equivalent of phosphorus pentachloride in dry benzene. The reactions of the phosphorimidic trichlorides were also studied.
Folate antagonists. 14. Synthesis of pyrazino[2,3‐f]quinazoline‐8,10‐diamines and related heterocycles as potential antimalarial agents (1,2)
Authors: Johnson Judith , Elslager Edward F. , Werbel Leslie M. 
Published: April 2009

AbstractAmination of 5‐chloro‐6‐nitro‐2,4‐quinazolinediamine (2) afforded 6‐nitro‐2,4,5‐quinazolinetriamine (3) which was hydrogenated catalytically to produce 2,4,5,6‐quinazolinetetraamine (5). Condensation of 5 with the requisite diketones afforded 8,9,10,11‐tetrahydropyrimido[5,4‐a]‐phenazine‐1,3‐diamine (6), several pyrazino[2,3‐f]quinazoline‐8,10‐diamines (7–10,13) as well as two pyrimido[4,5‐f]phenazinediamines (11,12). Amination of 2 in the presence of formamide at 120° led to the formation of 9‐nitro‐1H‐pyrimido[4,5,6‐de]quinazolin‐5‐amine (4). None of these compounds showed suppressive activity when tested parenterally against lethal Plasmodium berghei infections in mice. When tested against various bacteria in vitro, 7 and 10 exhibited activity against Streptococcus faecalis at a concentration below 2.5 μg./ml.
Synthesis of a bridgehead nitrogen system. Imidazo[1,5‐b]pyridazine derivatives
Authors: Migliara Onofrio , Petruso Salvatore , Sprio Vincenzo 
Published: April 2009

Abstract3,4‐Dibenzoyl‐2‐oxobutyrate 4‐semicarbazone (6a), ethyl 2,4‐dioxo‐3‐phenacylvalerate 3‐semicarbazone (6b) and diethyl phenacyloxalectate 3‐semicarbazone (6c) via acid catalysed intramolecular cyclization afforded 2‐phenyl‐4‐R‐3H‐imidazo[1,5‐d]pyridazine‐5,7‐(6H)diones (8d,e,f). Elemental analyses and spectroscopic data (ir, nmr, ms) were in good agreement with the assigned structures.
Pyrimidine derivatives and related compounds. A novel synthesis of pyrimidines, pyrazolo[4,3‐d]pyrimidines and isoxazolo[4,3‐d] pyrimidine
Authors: Elnagdi Mohamed Hilmy , Fahmy Shereif Mahmoud , Hafez Ebtisam Abdel Aziz , Elmoghayar Mohamed Riffaat Hamza , Amer Samir Abdel Rahman 
Published: April 2009

AbstractBenzoylacetonitrile (II) reacted with trichloroacetonitrile (III) to yield the β‐amino‐β‐trichloromethylacrylonitrile IV. Compound IV reacted with hydrazine hydrate to yield 5‐amino‐4‐cyano‐3‐phenylpyrazole (V) and with 2‐aminopyridine to yield the aminopyridine derivative VIII (cf., Chart I). Compound IV reacted with III to yield 2,4‐bis(trichloromethyl)‐5‐cyano‐6‐phenylpyrimidine (I) which could be converted into a variety of pyrazolo[4,3‐d]pyrimidine derivatives by treatment with hydrazine hydrate under a variety of different experimental conditions (cf., Chart II).