bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reaction of 2,3‐diphenylpyrazine 1‐oxides with acetic anhydride
Authors: Ohta Akihiro , Inoue Masami , Yamada Junichi , Yamada Yasuhiko , Kurihara Teruo , Honda Toshihiro 
Published: April 2009

AbstractSome 2,3‐diphenylpyrazine 1‐oxides were heated with acetic anhydride to give the corresponding 2,3‐di‐acetoxy‐2,3‐dihydro‐5,6‐diphenylpyrazines. By X‐ray diffraction analysis, the configuration of two acetoxyl groups was determined to be trans.
Xanthobilirubic acid and its amides. Synthesis, spectroscopy, and solution structures
Authors: Lightner D. A. , Ma J.‐S. , Adams T. C. , Franklin R. W. , Landen G. L. 
Published: April 2009

AbstractXanthobilirubic acid, 5‐[1,5‐didehydro‐3‐ethyl‐4‐methyl‐5‐oxo‐2H‐pyrrol‐2‐ylidene)methyl]‐2,4‐dimethyl‐1H‐pyrrol‐3‐propanoic acid, its methyl ester, amide, N‐methylamide and dimethylamide, and kryptopyrromethenone have been synthesized and characterized spectroscopically. In d6‐DMSO solution all pyrromethenones were monomeric, with lactam and pyrrole N‐Hs H‐bonded to solvent. In deuteriochloroform, the pyrromethenones preferred a dimeric form, with intramolecular H‐bonding between the lactam C = 0 of one unit and the lactam and pyrrole N‐Hs of the second.
Saturated heterocycles. 57. Synthesis of 4‐substituted‐9,10‐dialkoxy‐1,6,7,11b‐tetrahydro‐2H‐pyrimido[6,1‐a]isoquinolin‐2‐ones
Authors: Kóbor Jenö , Fülöp Ferenc , Sami El‐Gharib M. , Bernáth Gábor 
Published: April 2009

AbstractA large number of 4‐substituted‐9,10‐dialkoxy‐1,6,7,11b‐tetrahydropyrimido[6,1‐a]isoquinolin‐2‐ones were prepared by the reaction of 1‐(ethoxycarbonylmethyl)‐6,7‐dialkoxy‐1,2,3,4‐tetrahydroisoquinolines with iminoethers. Reaction of the corresponding isoquinoline‐1‐acetic acid derivatives with iminoethers led to the formation of N‐acyl‐1,2,3,4‐tetrahydroisoquinolin‐1‐acetamides. In the hydrolysis of the prepared 4‐substituted‐pyrimido[6,1‐a]isoquinolin‐2‐ones, the corresponding N‐acyl‐1,2,3,4‐tetrahydroisoquinolin‐1‐acetamides were obtained. While reduction of the 4‐phenyl derivative resulted in the corresponding 1,3,4,6,7,11b‐hexahydropyrimidinone. The steric structures of the tetrahydro‐ and hexahydropyrimido[6,1‐a]isoquinolines were determined by nmr spectroscopy.
Chemistry of the phenoxathiins and isosterically related heterocycles. XXIX The crystal and molecular structure of 5‐(3′‐hydroxypyridyl‐2′‐thio)‐4‐nitro‐1‐methylimidazole
Authors: Puig‐Torres Salvador , Martin Gary E. , Larson Steven B. , Simonsen Stanley H. 
Published: April 2009

AbstractReaction of the dianion of 3‐hydroxypyridine‐2(1H)‐thione with 5‐chloro‐4‐nitro‐1‐methylimidazole in N,N‐dimethylformamide led to the formation of 5‐(3′‐hydroxypyridyl‐2′‐thio)‐4‐nitro‐1‐methylimidazole, which failed to cyclize to the desired pyrid[1,4]oxathiinoimidazole derivative. In an effort to determine why the intermediate phenolate sulfide had failed to cyclize, the crystal structure of the isolated product was determined. The structure refined to R = 0.036.
The compounds related to 3‐(1‐imidazolyl)‐2‐alken‐1‐ones. Preparation and reactions
Authors: Kashima Choji , Tajima Tadakuni , Omote And Yoshimori 
Published: April 2009

AbstractCompounds related to 3‐(1‐imidazolyl)‐2‐alken‐1‐ones, 3‐(1‐imidazolyl)‐2‐alkenoic acid derivatives and 2‐alken‐1‐ones having heterocycles on the C‐3 carbon were prepared. The reaction of nucleophiles with these compounds was also discussed.
2‐pyridyl‐5‐alkyloxyphenyl‐1,3,4‐thiadiazoles by the action of sulfur on methylpyridines in the presence of alkyloxybenzoylhydrazines
Authors: Mazzone Gioacchino , Puglisi Giovanni , Marchetta Giovanna , Corsaro Antonino 
Published: April 2009

AbstractTitle thiadiazoles were obtained by reaction of sulfur and methylpyridines in the presence of alkyloxybenzoylhydazines. Corresponding oxadiazoles together with symmetrical 2,5‐dialkyloxyphenyl‐1,3,4‐thiadiazoles were also isolated as by‐products. The formation of different reaction products is rationalized.
1,3‐dipolar cycloaddition of methyl 3‐(1‐imidazolyl)acrylate and related compounds
Authors: Kashima Choji , Tsuzuki Atsushi , Tajima Tadakuni 
Published: April 2009

AbstractThe 1,3‐dipolar cycloaddition reaction of 1‐vinylimidazole and β‐(1‐imidazolyl)‐α,β‐unsaturated carboxylic esters with N.α‐diphenylnitrone and acetonitrile oxide was carried out and compared with those of β‐pyrrolidinyl‐ and β‐phenyl‐α,β‐unsaturated carboxylic esters. The imidazolyl moiety bonded to olefinic double bond was suggested to have properties intermediate to pyrrolidinyl and phenyl groups.
Synthesis of 3,5‐disubstituted 1,3,4‐oxadiazole‐2‐thiones as potential fungicidal agents
Authors: Goswami B. N. , Kataky J. C. S. , Baruah J. N. , Nath S. C. 
Published: April 2009

AbstractSixteen new 3‐arylaminomethyl‐5‐(2,4‐dichlorophenyl)‐1,3,4‐oxadiazole‐2‐thione and six 3‐alkyl aryl alkyl‐5‐(2,4‐dichlorophenyl)‐1,3,4‐oxadiazole‐2‐thiones were synthesised and characterised by their sharp melting points, elemental analysis, ir, 1H nmr and mass spectra. These substituted oxadiazolethiones were screened for their fungitoxic properties. Most of the compounds showed toxicity against two test organisms, Curvularia verruciformis and Alternaria tenuis. The degree of inhibition ranged from 38‐‐100% for a few compounds.
Combined application of auto‐correlated (COSY) and homonuclear J‐resolved two‐dimensional NMR spectra for the assignment of congested, non‐first order spectra of polycyclic aromatic systems. Assignment of the 1H‐NMR spectrum of benzo[2,3]phenanthro‐[4,5‐bcd]thiophene and an investigation of long range 1H‐1H spin‐coupling constants
Authors: Musmar M. J. , Gampe Robert T. , Martin Gary E. , Layton W. John , Smith Stanford L. , Thompson Robert D. , Iwao Masatomo , Lee Milton L. , Castle Raymond N. 
Published: April 2009

AbstractTotal assignment of the proton nmr spectrum of benzo[2,3]phenanthro[4,5‐bcd]thiophene at 200 MHz is reported. Preliminary identification of the resonances comprising the individual spin Systems was accomplished by the use of auto‐correlated two‐dimensional proton nmr spectroscopy (COSY). Individual assignments were made on the basis of spin‐coupling information which was obtained from the “titled” two‐dimensional J‐resolved (2DJ) proton nmr spectrum of the title compound. Because of the greater resolving power of the latter experiment relative to conventional proton nmr spectroscopy, a number of long range inter‐ring spincouplings were observed. The observation of these long range couplings was crucial to the final assignment of several of the resonances in the spectrum. Resonances due to strong coupling in the 2DJ spectrum were also shown to be a useful means of correlating strongly coupled spins which provides an alternative to the COSY spectrum for this purpose.
Studies on arylhydrazonoisoxazolinethiones. Behaviour of 4‐arylhydrazono‐3‐phenyl‐2‐isoxazoline‐5‐thiones toward hydrazines, grignard reagents and alkylating agents
Authors: Abd Allah Sanaa O. , Elmoghayar Mohamed R. , Abdou Sadek E. 
Published: April 2009

AbstractThe 4‐arylhydrazono‐3‐phenyl‐2‐isoxazoline‐5‐thiones 2 react with hydrazines to yield the 5‐hydrazones 3 and 5. The reaction of 2 with Grignard reagent resulted in addition of the reagent to the thiocarbonyl group to yield 7. Treatment of 2 with diazomethane effected S‐ and N‐methylation beside 1,2,3‐triazole derivative 11 obtained through isomerisation. The potassium salt of 2 react with alkyl halides to yield the S‐alkyl derivatives 12.
Hydrolysis of ureas. Kinetics and mechanism of the basic hydrolysis of indole‐1‐carboxamides and (5H‐dibenz[b,f]azepine)‐5‐carboxamide
Authors: Linda Paolo , Ebert Cynthia , Lovrecich Mara , Rubessa Fulvio 
Published: April 2009

AbstractThe hydroxide ion catalyzed hydrolysis of indole‐1‐carboxamide and indole‐1‐(N,N‐dimethyl)carboxamide has been studied in water at 60.0° and [OH−] concentration between 0.3‐‐2.4N. The rate constants of formation of the tetrahedral intermediate are strongly increased by N‐substitution with a heteroaromatic ring in comparison with simple amides. Carbamazepine, (5H‐dibenz[b,f]azepine)‐5‐carboxamide, a potent anticonvulsant drug, is particularly stable under these conditions.
Imidazolyl derivatives of the chroman ring. 1
Authors: Cozzi Paolo , Mongelli Nicola , Pillan Antonio 
Published: April 2009

AbstractThe synthesis of 2‐(1H‐imidazol‐1‐yl)‐2,3‐dihydro‐2H‐1‐benzopyran‐4‐ones (I) through 3‐bromo‐2,3‐dihydro‐4H‐1‐benzopyran‐4‐ones or more conveniently through chroman ring closure from 2‐(1H‐imidazol‐1‐yl)‐2′‐hydroxyacetophenones is described. The ring closure also works well for the pyrazolyl derivatives. Compounds I and the corresponding imidazolylchromanols, ‐chromenes, and ‐chromans derived from the former, were pharmacologically investigated.
Reactions with 1,8‐naphthosultam. Synthesis of [1,2]benzisothiazolo[2,3,4‐cde]benzotriazole 4,4‐dioxide. A new ring system
Authors: Hammouda Hamdy A. , El‐Reedy Ahmed M. , Sharaf Mohie A. F. , Abdel‐Fattah A. M. 
Published: April 2009

Abstract1,8‐Naphthosultam (I) coupled with arenediazonium salts to give the 4‐arylazo‐ VII, and the 2,4‐bisarylazo‐1,8‐naphthosultams, VIa‐c. On the other hand, coupling of the 4‐substituted 1,8‐naphthosultams afforded the 2‐phenylazo derivatives, IIa,b. Reduction of IIa,b gave the 2‐amino compounds IVa,b, which reacted with nitrous acid to give the [1,2]benzisothiazolo[2,3,4‐cde]benzotriazoles, Va,b, establishing thus a new ring system. The nitro analogue Vc was also synthesized.
Thiophene analogues of carcinogenic polycyclic hydrocarbons. Elbs pyrolysis of various aroylmethylbenzo[b]thiophenes
Authors: Croisy Alain , Mispelter Joël , Lhoste Jean‐Marc , Zajdela François , Jacquignon Pierre 
Published: April 2009

AbstractThe synthesis of benzonaphthothiophenes 9 and 10 and of benzophenanthrothiophenes 14–17 through Elbs cyclodehydration of ortho‐methylated aroylbenzo[b]thiophenes is described. The occurrence of a rearrangement of the thiophene ring in the course of the cyclization is discussed as well as the influence of the temperature on a concurrent cyclodehydration process. Several of these poly‐condensed thiophenes were found carcinogenic in mice.
A facile synthesis of 8‐(β‐D‐ribofuranosyl)‐4‐thioxo‐3H‐pyrazolo[1,5‐a]‐1,3,5‐triazine and its α‐anomer
Authors: Chu Chung K. 
Published: April 2009

AbstractA versatile intermediate 2 for C‐nucleoside synthesis was treated with thiosemicarbazide to obtain thiosemicarbazone 6, which was then converted to 3‐aminopyrazol‐2N‐thiocarboxamide derivatives 7 and 8 by the reaction of 6 and sodium ethoxide. 4‐Thioxo‐4H‐pyrazolo[1,5‐a]‐1,3,5‐triazine C‐nucleosides 11 and 12 were obtained by the ring closure reaction of 7 and 8 with triethyl orthoformate. Brief treatment of 11 and 12 with 10% methanolic hydrogen chloride afforded C‐nucleosides 4 and 13, respectively, without anomerization. Identification of compounds 4 and 13 was made on the basis of 1H nmr and uv spectra, as well as chemical conversion to known compounds with established configurations. Model compounds were also synthesized in order to confirm the heterocyclic moieties.
Pyridazinderivate. XIX [1,2]. Massenspektrometrische untersuchung halogensubstituierter trans‐styrylpyridazine
Authors: Allmaier Günter , Heinisch Gottfried 
Published: April 2009

AbstractDie EI‐Massenspektren von 18 am Carbocyclus durch Fluor, Chlor bzw. Brom substituierten 3‐ bzw. 4‐Styrylpyridazinen werden diskutiert. Die Abhängigkeit der Fragmentierungsmuster von der Position der Stickstoffatome relativ zur Ethenylenbrücke erlaubt die eindeutige Differenzierung zwischen 3‐ und 4‐Pyridazinylverbindungen. Die Massenspektren von 3‐Styrylpyridazinderivaten mit ortho‐ständigem Halogen unterscheiden sich signifikant von denen der meta‐ und para‐Isomeren hinsichtlich der relativen Peakintensitäten der [M‐1]+‐ bzw. [M‐X]+‐ Ionen.
Ring opening reaction of N‐substituted dihydropyrimidines with metal hydride complexes
Authors: Kashima Choji , Shimizu Masao , Katoh Akira , Omote Yoshimori 
Published: April 2009

AbstractN‐Substituted dihydropyrimidines, 1, 3, and 4, easily afforded N,N′‐disubstituted 2,4‐diaminopentanes 2 in good yield by the ring opening reaction with sodium borohydride. The reaction with lithium aluminum hydride was also examined.
Chemistry of the phenoxathiins and isosterically related heterocycles. XXX. The crystal and molecular structure of 2‐AZA‐phenoxathiin 2‐oxide: Further evidence in support of the relationship between the 13C‐NMR chemical shift of C‐10a resonance and the molecular dihedral angle
Authors: Caldwell S. R. , Turley J. C. , Martin G. E. , Dwiggins C. A. , Hossain M. B. , Mendenhall J. V. , Van Der Helm D. 
Published: April 2009

AbstractThe synthesis of 2‐azaphenoxathiin 2‐oxide (4) and the total assignment of the 13C‐nmr spectrum is described. Facile assignment was obtained from the assigned spectrum of 2‐azaphenoxathiin with additivities obtained from a comparison of 1‐azaphenoxathiin and its N‐oxide. The crystal structure has also been determined from three dimensional X‐ray diffraction data. The compound crystallizes in the monoclinic space group P21/n with a = 17.50(2)Å, b = 7.147(3)Å, c = 16.044(7)Å, β = 110.60(5) and Z = 8. Intensity data were collected at ‐ 135 ± 2°C on an automatic diffractometer using nickel‐filtered CuKα radiation. The structure was solved by direct methods and was refined by least‐squares techniques to give a final R‐value of 0.045 for all 3831 independent reflections.
Electron impact mass spectrometry of some new macrocyclic tetraesters
Authors: Podda Gianni , Maccioni Antonio , Anchisi Carlo , Daolio Sergio , Pelli Beatrice , Traldi Pietro 
Published: April 2009

AbstractThe electron impact mass spectrometric behaviour of a new class of macrocyclic tetraesters is reported and discussed in detail with the aid of linked scans, exact mass measurements and collisionally activated decomposition mass analyzed ion kinetic energy spectra.
Thermolysis and photolysis of some 5‐amino‐4‐methoxycarbonyl‐Δ2‐1,2,3‐triazolines
Authors: Bourgois J. , Mathieu A. , Texier F. 
Published: April 2009

AbstractThermolysis of 5‐amino‐4‐methyl‐4‐methoxycarbonyl‐Δ2‐l,2,3‐triazolines leads to amidines and 1‐methoxycarbonyl diazoethane. If the N1 substituent is a tosyl or benzoyl group, the corresponding triazoline is not isolated, the azide addition to the olefin gives directly the thermolysis products at room temperature. Triazoline photolysis leads to amino aziridines which are azomethine ylids.
Studies on imidazole derivatives and related compounds. 3. Regioselective glycosylation of 4‐carbamoylimidazolium‐5‐olate
Authors: Tarumi Y. , Moriguchi K. , Atsumi T. 
Published: April 2009

AbstractIn the synthesis of glycosyl derivatives of 4‐carbamoylimidazolium‐5‐olate (2) by the silyl‐Hilbert‐Johnson method using trimethylsilyl trifluoromethanesulfonate as catalyst, we obtained N‐3 nucleosides 5 as major products and N‐1,N‐bis‐nucleosides 6 as minor ones. The desired N‐1 nucleosides 4 were isolated in only low yields. However, the yields of 4 were improved by adding ca. One equivalent of stannic chloride to the silylated 4‐carbamoylimidazolium‐5‐olate (3). On the basis of nuclear magnetic resonance (13C and 29Si) and ultraviolet spectroscopic studies, we verify the formation of σ‐complexes between the silylated base 3 and the Lewis acid (stannic chloride or trimethylsilyl trifluoromethanesulfonate), and the propose the structures of these complexes and the reaction mechanism.
Spiro‐ and bicyclic azalactams by hydrolysis of α‐chlorinated bicyclic amidines
Authors: Löfås Stefan , Ahlberg Per 
Published: April 2009

AbstractThe synthetic potential of α‐chlorinated bicyclic amidines to form spiro‐ and bicyclic azalactams on hydrolysis has been investigated. Thus, 2a,b, prepared by chlorination of 1a,b with carbon tetrachloride in DMF, were treated with water via hydrolysis of the amidine function and an intramolecular substitution, 2a, afforded the azaspirolactam 6a, and 2b gave the isomers 6b and 6c in the ratio 22:78, respectively. Similarly, α‐chlorinated DBU 3b gave the bicyclic azalactam 10. A high‐yield preparative method for obtaining the bicyclic amidine 1a was worked out on the basis of Reissert's method from 1893, starting from diethylmalonate and α‐bromopropylphthalimide.
On the acylation of 1,3‐benzoxathiole systems
Authors: Bernard Angela Maria , Cocco Maria Teresa , Congiu Cenzo , Plumitallo Antonio 
Published: April 2009

AbstractThe acylation on 1,3‐benzoxathiole systems, as well as the effect of the stoichiometry of the catalyst on the yields of ketones and of breaking products of the OCS bonds is here described.
The reaction of N‐aminophthalimide with isothiocyanates
Authors: Hearn Michael J. , Lucas Laura E. 
Published: April 2009

AbstractN‐Aminophthalimide (I) reacted in refluxing isopropyl alcohol with a number of isothiocyanates to give the related 1:1 addition products, N‐(3‐substitutedthioureido)phthalimides III. On the other hand, heating I directly with an excess of neat arylisothiocyanates produced the N‐arylphthalimides IV. As shown for IIIa, the 1:1 addition products are conveniently deblocked by the Ing‐Manske procedure to yield the 4‐substituted thiosemicarbazide.
Efficient synthesis of cytotoxic quinones: 2‐Acetyl‐4H,9H‐naphtho[2,3‐b]furan‐4,9‐dione (6) and (±)‐2‐(1‐hydroxyethyl)‐4H,9H‐naphtho[2,3‐b]furan‐4,9‐dione (7)
Authors: Lopes Cláudio C. , Lopes Rosangela S. C. , Pinto Antonio V. , Costa Paulo R. R. 
Published: April 2009

AbstractFrom the ethanol extract of the stem bark of Tabebuia cassinoides (Lam.) DC (Bignoniaceae), Kingston and Rao [1] isolated two new furonaphthoquinones 6 and 7 that showed activity in KB cell culture assay (ED50 1.0 and 2.0 μg/ml, respectively). These values may be significant since lapachol, which has an ED50 value of 4.4 μg/ml in the same assay, showed sufficient in vivo activity to reach clinical trial at the National Cancer Institute of the United States. The syntheses of these compounds (6 and 7) were realized in 36% overall yield starting from furan and phthalic anhydride.
Reaction ofN‐benzyl‐1,1′‐iminobis‐2‐butanols with 70% w/w sulfuric acid
Authors: Hernestam Sven , Stenvall Gillis , Olsson Thomas 
Published: April 2009

AbstractTreatment of (S:R)‐N‐benzyl‐1,1′‐iminobis‐2‐butanol with 70% w/w sulfuric acid givescis‐ andtrans‐N‐benzyl‐2,6‐diethylmorpholines (15 and 74%, respectively) andN‐alkenyl‐4‐ethyl‐1,2,3,4‐tetrahydroisoquinolines (5%). Hydrogenation of the reaction mixture givescis‐ andtrans‐2,6‐diethylmorpholines andN‐butyl‐4‐ethyl‐1,2,3,4‐tetrahydroisoquinoline. NeitherN‐benzyl‐N‐crotyl‐(2‐hydroxy‐1‐butyl)amine (4) norN‐benzyldicrotylamine (5) are intermediates in the reaction. (S:S)‐N‐Benzyl‐1,1′‐iminobis‐2‐butanol gives 95% ofcis‐N‐benzyl‐2,6‐diethylmorpholine and 1% of thetransisomer.
Aminopyrazoles. V. Structure assignment of 1H‐pyrazol‐3‐and 5‐amines by means of the 1H NMR δ(4‐H)‐values of their exo‐N‐toluenesulfonyl derivatives
Authors: Ege Günter , Franz Hermann 
Published: April 2009

AbstractFrom the extent of the low field chemical shift of 4‐H caused by exo‐N‐tosylation of 1‐substituted 1H‐pyrazolamines it is possible to distinguish between the 3‐ and 5‐amino‐isomers. The pyrazole substituent increment system of Tensmeyer and Ainsworth has been extended to 3‐ and 5‐amino, 3‐ and 5‐tosylamino, 1‐benzyl and 1‐tosyl substituents. By comparison of δ(4‐H) values, calculated with the aid of these increments, with measured δ(4‐H) values, a differentiation between 3‐ and 5‐tosylaminopyrazoles but not between 3‐ and 5‐aminopyrazoles can be made.
2‐(3,5‐Diaryl‐Δ4‐1,3,4‐thiadiazolin‐2‐yliden)‐1,3‐dithiole eine neue klasse elektronenreicher olefine
Authors: Krasuski Witold , Regitz Manfred 
Published: April 2009

AbstractDie Dithiolium‐perchlorate 3a und b lassen sich mit Tributylphosphin glatt in die Phosphonium‐perchlorate 4a und b umwandeln. Ihre Deprotonierung mit Butyllithium liefert die Methylenphosphorane 7 (nicht isoliert), aus denen man durch sukzessive Umsetzung mit den Δ4‐1,3,4‐Thiadiazolium‐perchloraten 5d und e und Triethylamin die elektronenreichen Olefine 9a‐d erhält. Die Olefinsynthese läßt sich auch auf umgekehrtem Wege, d.h. durch Reaktion der Phosphoniumsalze 6a‐c mit den Dithioliumsalzen 3a und b bei sonst gleichen Bedingungen ausführen. Auf diesem Wege wurden die elektronenreichen Olefine 9e‐h erhalten.
Polycondensed nitrogen heterocycles. Part 13. Pyrrolo[3,2‐b]indole by intramolecular nucleophilic substitution reaction in the pyrrole series
Authors: Aiello E. , Dattolo G. , Cirrincione G. , Almerico A. M. 
Published: April 2009

AbstractAn intramolecular nucleophilic substitution in the pyrrole series has been generalized. The behaviour of nitro, chlorine, bromine and iodine as leaving groups towards the nucleophilic amino group was observed. An acid catalyzed mechanism has been proposed.
Investigations into the synthesis of 6‐ethyl‐5‐(4‐pyridinyl)‐2,4‐pyrimidinediamine as a potential antimalarial agent
Authors: Hung Jocelyn , Werbel Leslie M. 
Published: April 2009

AbstractThe synthesis of 6‐ethyl‐5‐(4‐pyridinyl)‐2,4‐pyrimidinediamine (2), the pyridine analog of pyrimethamine, is described. Condensation of 4‐pyridineacetonitrile (3) with methyl propionate afforded α‐(1‐oxopropyl)‐4‐pyridineacetonitrile (4). Treatment with triethyl orthopropionate gave primarily the undesiredN‐alkylated material. However reaction of the crude mixture with guanidine afforded2in low yield. This material was devoid of significant antimalarial activity.
(8,9‐Dihydro‐7H‐imidazo[1,2‐c][1,3]diazepin‐5‐yl)‐cyanamide und homologe imidazo‐bizyklen
Authors: Buschauer A. , Schunack W. 
Published: April 2009

AbstractDie Reaktion der 2‐(ω‐Aminoalkyl)‐imidazole 4a‐f mit N‐Cyanodiphenyl‐imidocarbonat (7) führt zu den entsprechend hydrierten Imidazo[1,5‐a]imidazolen, Imidazo[1,2‐c][1,3]diazepinen und Imidazo[1,2‐c][1,3]diazocinen (9a‐f), die im Verhalten gegenüber Nucleophilen und in ihren spektroskopischen Eigenschaften den (7,8‐Dihydro‐imidazo[1,2‐c]pyrimidin‐5‐yl)‐cyanamiden (3) [1] vergleichbar sind.
Studies on imidazole derivatives and related compounds. 4. Synthesis of O‐glycosides of 4‐carbamoylimidazolium‐5‐olate
Authors: Tarumi Y. , Takebayashi Y. , Atsumi T. 
Published: April 2009

AbstractRibosylation of trimethylsilyl derivative of 1‐(4‐nitrobenzyl)‐5‐carbamoylimidazolium‐4‐olate (5) with 1,2,3,5‐tetra‐O‐acetyl‐β‐D‐ribofuranose in the presence of stannic chloride and trimethylsilyl trifluoromethanesulfonate afforded no 5‐O‐glycosides but N‐1 ribosylated compound (6). However, 5‐O‐riboside (7a) and its orthoamide derivative (8) were given by glycosylation of tri‐n‐butylstannyl derivative of 5 with 2,3,5‐tri‐O‐acetyl‐β‐D‐ribofuranosyl chloride in the presence of silver trifluoromethanesulfonate. This procedure was successfully applied to other sugars and 5‐O‐glucuronide (11), a possible metabolite of 1 in vivo, was obtained as one of the 5‐O‐glycoside derivatives.
Pyrazino[2,3‐c][1,2,6]thiadiazine 2,2‐dioxides. Sulfur dioxide analogs of pteridines
Authors: Goya Pilar , Paez Juan Antonio , Pfleiderer Wolfgang 
Published: April 2009

AbstractSeveral pyrazino[2,3‐c][1,2,6]thiadiazine 2,2‐dioxide derivatives have been synthesized for the first time by condensation of suitable 4,5‐diamino‐1,2,6‐thiadiazine 1,1‐dioxides and symmetrical 1,2‐dicarbonyl compounds. Structures of these compounds have been characterized by their elementary analyses, 1H‐nmr and uv spectra as well as their pKa values. The most striking differences between this series and the corresponding pteridines are discussed.