bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chiral 1,4‐benzodiazepines. XII. Conformation in a solution of 7‐chloro‐5‐phenyl‐3(S)methyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepine
Authors: Decorte E. , Toso R. , Fajdiga T. , Comisso G. , Moimas F. , Sega A. , Sunjić V. , Lisini A. 
Published: March 2009

AbstractDeuterium labeled congeners of 7‐chloro‐5‐phenyl‐3(S)‐methyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepine (8), i.e., compounds 9 and 16‐18 were prepared and their lis‐nmr spectra run. For computational studies compounds 9 and 16 were chosen. The results of lis measurements revealed that 16 is present in more than 97% in the boat‐like conformation I (Scheme 3).
Novel synthesis of 5,11‐dihydro‐6H‐pyrido[2,3‐b]‐[1,4]benzodiazepin‐6‐ones and related studies
Authors: Oklobdžija M. , Comisso G. , Decorte E. , Fajdiga T. , Gratton G. , Moimas F. , Toso R. , Šunjić V. 
Published: March 2009

Abstract5,11‐Dihydro‐6H‐pyrido[2,3‐6][1,4]benzodiazepin‐6‐one (1), a basic intermediate in the preparation of 11‐α‐aminoacetyl derivatives with important biological activities, has been obtained by a three‐step synthesis starting from easily available isatoic anhydride and anhydro ornithine. Some model cyclisation reactions leading to 5‐member ring derivatives 10 and 12 instead of 7‐member ring analogues of 1, are reported. Easy transformations of the tetrahydro congener of 1, i.e., compound 4 into 19, which actually represents a tetrahedral intermediate in the transformation of 5 into 4, is noticed. Further rearrangement of 19 into spiro compound 20, and return of the latter into 5 is described.
Attempts at new synthesis of 5,11 ‐Dihydro‐6H‐pyrido[2,3‐b][1,4]benzodiazepin‐6‐one
Authors: Oklobdžija M. , Comisso G. , Decorte E. , Kovač T. , Angeli C. , Moimas F. , Zanon P. , Zonno F. , Toso R. , Šunjić V. 
Published: March 2009

AbstractAttempting some new approaches to 5,11‐dihyro‐6H‐pyrido[2,3‐b][1,4]benzodiazepin‐6‐one (6), compounds 8, 10 and 11 were prepared. Ring enlargement of 4 into 6 failed, as well as condensation of 10 and 11 into ID, which is the potential precursor of pirenzepin (11‐[2′‐(4″‐methylpiperazin‐1″‐yl)]acetyl derivative of 6) via an envisaged intramolecular Diels‐Alder reaction. Model compounds 5 and 13 were prepared and their behaviour in analogous reactions explained the failures of the intended transformations of 4, as well as of condensation of 10 and 11.
Friedländer condensation of 1H‐pyrazolin‐5‐ones with O‐aminobenzaldehydes. Synthesis of 1H‐pyrazolo[3,4‐B]quinolines
Authors: Tomasik Danuta , Tomasik Piotr , Abramovitch Rudolph A. 
Published: March 2009

AbstractAll the possible 1‐ and 3‐monomethyl, monophenyl, dimethyl, diphenyl, and methylphenyl‐1H‐pyrazolin‐5‐ones have been condensed with o‐aminobenzaldehyde. In some cases (but not all) 1‐H‐pyrazolo[3,4‐b]quinolines (10) are formed together with a variety of other products. The balance between formation of hydrazone 11 and the ring‐closed 10 is discussed, as is the formation of other products obtained in these condensations.
Imino‐Bridged heterocycles. V . Synthesis of 6,11‐dimethyl‐1 1H‐benzo[5,6]cyclohepta[1,2‐c]pyridin‐6,11‐imine by a regiospecific amide to olefin cyclization
Authors: Brenner Daniel G. , Halczenko Wasyl , Shepard Kenneth L. 
Published: March 2009

AbstractAttempted utilization of sulfenimines 6a,b to prepare tertiary carbinamines as intermediates to the desired 6,11‐dimethyl‐11H‐benzo[5,6]cyclohepta[1,2‐c]pyridin‐6,11‐imine system (10) instead gave products resulting from nitrogen‐sulfur bond cleavage. The preparation and use of the corresponding sulfonimine 8, however, led to 10 through a regiospecific base‐catalyzed reaction.
Synthesis of heterocyclic compounds from o‐aminobenzenethiol and ammonium thiocarbamate
Authors: D'Amico John J. , Fuhrhop Ralph W. , Bollinger Frederic G. , Dahl William E. 
Published: March 2009

AbstractThe reaction of o‐aminobenzenethiol with carbonyl sulfide in the presence of triethylamine afforded an alternate route for the synthesis of 2‐benzothiazolinone (1) in 97–98% yield. The reaction of ammonium thiocarbamate (2) with 2‐chlorocyclohexanone furnished the novel 4,5,6,7‐tetrahydro‐2‐benzothiazolinone (3). 3‐Ethoxy‐2H‐1,4‐benzothiazin‐2‐one (7) was prepared by the reaction of o‐aminobenzenethiol with diethyl oxalate. Possible pathways and supporting nmr, ir and mass spectra are discussed.
Synthesis of 4‐hydrazino‐5H‐pyrimido[5,4‐b]indole and related compounds
Authors: Monge A. , Palop J. A. , Goñi T. , Martinez‐Crespo F. , Recalde I. , Fernandez‐Alvarez E. 
Published: March 2009

AbstractThis paper describes the synthesis of two 4‐amino‐5H‐pyrimido[5,4‐b]indoles 5, 4‐hydrazino‐5H‐pyrimido[5,4‐b]indole 6, two 1,2,4‐triazolo[4,3‐c]pyrimido[5,4‐b]indoles 8, and tetrazolo[4,5‐c]pyrimido[5,4‐b]indole 10. Starting with ethyl 3‐aminoindole‐2‐carboxylate 1, 5H‐pyrimido[5,4‐b]indol‐4‐one 2 was obtained (80%) by condensing with formamide. Reactions of 2 with phosphorus oxychloride and phosphorus pentasulfide gave respectively, 4‐chloro‐5H‐pyrimido[5,4‐b]indole 3 (70%) and 5H‐pyrimido[5,4‐b]indole‐4‐thione 4 (80%). Compound 3 reacted with amines (morpholine, piperidine) to give the respective 4‐amino‐5H‐pyrimido[5,4‐b]‐indoles 5, and compound 4 reacted with hydrazine to give 4‐hydrazino‐5H‐pyrimido[5,4‐b]indole 6 (80%). Two hydrazones of 6 (benzylidene, isopropylidene) 7 were also prepared (90%). Compound 6 reacted with formic and acetic acids to give (65–75%) the respective 1,2,4‐triazolo[4,3‐c]pyrimido[5,4‐b]indoles 8 and with nitrous acid to give tetrazolo[4,5‐c]pyrimido[5,4‐b]indole 9 (85%). All the new compounds 2 to 9 were characterized by elemental analysis and spectral data (ir, nmr).
Zur protonenkatalysierten elektrophilen substitution von 2,3‐dimethylindol mit arylaldehyden: C6‐regioselektivität am indol‐gerüst
Authors: Schiffl E. , Pindur U. 
Published: March 2009

AbstractThe proton catalyzed reaction of 2,3‐dimethylindole (1) with several arylaldehydes 2 yields the 6,6′bisindolylarylmethanes 5 regioselectively. No mechanistic information about the predominant attack of the aldehydes on the indole nucleus is obtained, because the reaction proceeds too fast to control. The electron‐rich aldehydes, 2,4,6‐trimethoxybenzaldehyde and indole‐3‐carbaldehyde, yield exclusively the 6,6′,6″‐trisin‐dolylmethane 9. The constitutions of all isolated methanes were elucidated by 400 MHz 1H‐nmr spectroscopy.
Optically active synthons containing tetra‐ and dihydropyrimidine rings
Authors: Weis Alexander L. , Frolow Felix , Vishkautsan Rosita 
Published: March 2009

AbstractOptically active condensed derivatives of hydroxytetrahydropyrimidines and dihydropyrimidines were prepared by condensation of (+)pulegone with amidines and guanidine. The structure, the possible mechanism of formation of these compounds, and the existence of amidinic tautomerism are discussed on the basis of the measured spectral data and x‐ray diffraction analysis.
Synthèse d'hétérocycles polycondensés à partir de benzopyranno‐1 as‐triazinones
Authors: Vinot Nicole , Maitte Pierre 
Published: March 2009

AbstractPar des réactions de substitution sur le carbonyle des benzopyranno‐1 as‐triazinones 1 et 2 il est facile de préparer les chloro, hydrazino et aminobenzopyranno‐1 as‐triazines. Ces composés, par condensation avec les acides ou les cétones α‐bromées, ont permis la synthèse de triazolo et imidazolobenzopyranno‐1 as‐triazines 9, 10, 17, 18. Enfin la réaction classique du nitrite de sodium sur les hydrazinotriazines donne les tétrazolotriazines 13, 14.
Mass spectral fragmentation patterns of heterocycles. IX . Investigation of fundamental processes in 5H‐dibenz[b,f]azepines and dihydro‐5H‐dibenz[b,f]azepines
Authors: Al‐Showaier Ibrahim , Hallberg Anders , Schram Karl H. , Martin Arnold R. 
Published: March 2009

AbstractElectron impact induced fragmentation patterns of 5H‐dibenz[b,f]azepine (1a), 10,11‐dihydro‐5H‐dibenz‐[b,f]azepine (2a) and some 5‐substituted derivatives were investigated using metastable ion studies, exact mass measurements and deuterated analogues. Studies employing 4,6‐dideuterio derivatives indicate that the formations of ions of m/e 191, 180, 167, 166 and 152 are associated with a variety of skeletal reorganization processes accompanied by hydrogen (or deuterium) transfers involving peri (4‐ or 6‐) hydrogen (or deuterium) atoms. The methyl radical expelled in the formation of the M‐15 ion in the spectrum of 2a is derived from the benzylic carbon(s). A similar process is, in part, responsible for the expulsion of a methyl radical from the molecular ion of 5‐methyl‐10,1 1‐dihydro‐5H‐dibenz[b,f]azepine (2c) based on the fragmentation of the trideuteriomethyl derivative (2d). Side chain α‐cleavage processes dominate the spectra of (5H‐dibenz[b,f]azepine‐5‐yl)acetaldehyde diethylacetal and its 10,11‐dihydro analogue. Hydrogen atom transfer processes involving benzylic hydrogen atoms occur in the fragmentation of the 10,11‐dihydro‐5H‐dibenz[b,f]azepines 2a, 2c and 2e.
Syntheses and reactions of some 1‐substituted‐7‐alkyl‐2‐thioxopurines: X‐Ray structure of 6‐methylamino‐7‐nonyl‐2‐thioxopurine
Authors: Grözinger Karl G. , Onan Kay D. 
Published: March 2009

AbstractSeveral 1‐substituted‐7‐alkyl‐2‐thioxopurines 8,9,10 were synthesized by the reaction of isothiocyanates with 1‐alkyl‐4‐amino‐5‐cyanoimidazoles 3. Treatment of 3 with methyl isothiocyanate gave the Dimroth rearranged product 6‐methylamino‐7‐alkyl‐2‐thioxopurines 11. The structure of 11 was unambiguously defined by X‐ray crystallography.
Antibakterielle wirkstoffe. IX . Die aminomethinylierung im system des 3‐methyi‐1‐(4‐nitrophenyl)‐2‐pyrazolin‐5‐ons
Authors: Kreutzberger Alfred , Kolter Karl 
Published: March 2009

AbstractDie mit Hilfe von s‐Triazin (1) durchgeführte Aminomethinylierung von 3‐Methyl‐1‐(4‐nitrophenyl)‐2‐pyrazolin‐5‐on (2) führt zu dem Aminomethinylierungsprodukt 4 und dem C‐Rubazonsäuretypus 5. In den zur Untermauerung der erhaltenen Strukturen aufgenommenen Massenspektren treten als charakteristische Fragmente von 4 das Pyrazolo[4,3‐d]isoxazolyliumion 6 (m/e 245), p‐Benzochinonmonoiminylkation (m/e 106) und Mthylenaminophenylkation (m/e 104) auf.
Interaction of 2,4,6‐heptanetrione with 1,5‐diamino‐3‐azapentane and similar polyamines. The crystal and molecular structure of a new heterocyclic compound
Authors: Fregona D. , Sitran S. , Vigato P. A. , Casellato U. , Graziani R. 
Published: March 2009

AbstractThe pathway of the reaction between 2,4,6‐heptanetrione and 1,5‐diamine‐3‐aza‐pentane was studied and some products identified by ir, uv, mass spectra and x‐ray diffractometry. This reaction is not a simple condensation with the formation of a Schiff base but a more complicated process. The structure of the final compound was determined by x‐ray crystallography and refined to R = 0.047. Crystals are triclinic, space group Pl, with a = 11.795(5), b = 9.779(5), c = 7.801(5) Å, α = 101.74(3), β = 90.93(3), γ = 110.65(3), Dx = 1.27 g. cm−3 for Z = 2. The structure is essentially formed by three heterorings two of which have a common edge. Only the 4‐pyridone ring is planar.As expected 1,5‐diamino‐3‐thiapentane reacts with the same triketone, in 1:1 or 1:2 molar ratios, to give the acyclic or macrocyclic Schiff bases.
Synthesis of the angular furanoxanthone, deoxydehydropsorospermin methyl ether (5,10‐dimethoxy‐2‐isopropenyl‐6H‐furo[2,3‐c]xanthen‐6‐one)
Authors: Scannell Ralph T. , Stevenson Robert 
Published: March 2009

AbstractThe angular isopropenylfuranoxanthone heterocyclic system, on which the anti‐leukemic natural product psorospermin is based, is synthesized by the reaction of cuprous isopropenylacetylide with 4‐bromo‐1,5‐dimethoxy‐3‐hydroxyxanthone.
Selenium heterocycles. XXXVII . Synthesis of 4‐(thiazol‐4‐yl)‐1,2,3‐selenadiazoles and 4‐(selenazol‐4‐yl)‐1,2,3‐selenadiazoles
Authors: Shafiee A. , Anaraki M. , Bazzaz A. 
Published: March 2009

AbstractStarting from readily available 2‐substituted‐4‐formylthiazoles and selenazoles, a series of 4‐(2‐aryl‐4‐selenazolyl)‐1,2,3‐selenadiazoles I and 4‐(2‐substituted‐4‐thiazolyl)‐1,2,3‐selenadiazoles II were prepared. Pyrolysis of compound II afforded (2‐substituted‐4‐thiazolyl) acetylenes VII. Addition of potassium hydroxide pellets to an alcoholic solution of II gave 2‐substituted‐1,4‐diselenafulvenes VIII. Decomposition of compound II with base followed by the addition of carbon disulfide gave 5‐substituted 2‐thioxo‐1,3‐thiaselenoles XI.
Reactions of sulfur monochloride with some aromatic aldehyde semicarbazones and thiosemicarbazones: New syntheses of substituted 2,4‐dihydro‐1,2,4‐triazol‐3‐ones, 2,4‐dihydro‐1,2,4‐triazole‐3‐thiones and 2‐amino‐1,3,4‐oxadiazoles
Authors: Milcent René , Nguyen Thu‐Huong 
Published: March 2009

AbstractTreatment of various substituted semicarbazones of aromatic aldehydes with sulfur monochloride yields the corresponding substituted 2,4‐dihydro‐1,2,4‐triazol‐3‐ones. With thiosemicarbazones, the products are derivatives either of the 2‐amino‐1,3,4 thiadiazole or of the 2,4‐dihydro‐1,2,4‐triazole‐3‐thione depending on the experimental conditions.
Azolopyrimidines and pyrimidoquinazolines from 4‐chloropyrimidines
Authors: El‐Reedy A. M. , Ayyad A. O. , Ali A. S. 
Published: March 2009

Abstract5‐Cyano‐3,4‐dihydro‐6‐phenyl‐2‐substitutedpyrimidin‐4‐ones 1a‐c reacted with phosphorus oxychloride to give the corresponding 4‐chloropyrimidine derivatives IIa‐c. Compounds IIa‐c reacted with aniline and hydrazine to yield the 4‐anilino, IIIa,e, and 4‐hydrazino, IIIb‐d derivatives. The 4‐hydrazino analogues IIIb,c could be converted into the triazolo[4,3‐c] and tetrazolo[4,5‐c]pyrimidines IV and V by the action of carbon disulphide and nitrous acid, respectively. The reaction of IIb,c with phenylhydrazine afforded directly the 5‐amino‐4,6‐diphenyl‐6H‐2‐substitutedpyrazolo[3,4‐d]pyrimidines VIa,b. The 4‐chloro derivative IIa reacted with antrhanilic acid to form the 5‐cyano‐2,4‐diphenyl‐6‐(o‐carboxyphenylamino)pyrimidine VIII, which could be cyclised into the 4‐cyano‐1,3‐diphenyl‐10H‐pyrimido[6,1‐b]quinazolin‐10‐one IX by heating with acetic anhydride.
The synthesis of 5‐azaindoles by substitution‐rearrangement of 7‐azaindoles upon treatment with certain primary amines
Authors: Girgis Nabih S. , Larson Steven B. , Robins Roland K. , Cottam Howard B. 
Published: March 2009

AbstractCertain 4‐substituted 1H‐pyrrolo[2,3‐b]pyridines (7‐azaindoles) undergo a nucleophilic substitution‐rearrangement upon treatment with various primary amines at elevated temperatures to yield N‐1‐substituted 4‐amino‐1H‐pyrrolo[3,2‐c]pyridines (5‐azaindoles). Treatment of the same 7‐azaindoles with secondary amines under the same reaction conditions led to simple nucleophilic substitution products.
Novel tricyclic heterocycles (benzopyrrocolines) arising via carbanion attack on a nitrile function
Authors: Gibson Harry W. 
Published: March 2009

AbstractA new reaction of 2‐n‐alkanoyl‐1,2‐dihydroisoquinaldonitriles 1 (isoquinoline Reissert compounds) has been discovered. As previously reported reaction of the conjugate bases of Reissert compounds with alkyl halides yields the corresponding 1‐alkyl derivatives 2. However, compounds 2, R = n‐alkyl, with only a catalytic amount of bases form the enolate ion, which attacks the neighboring nitrile functionality to produce directly in the same reaction vessel excellent yields of benzopyrrocoline derivatives 5‐10. The nmr spectrum reveals a solvent dependent tautomeric equilibrium between ketoeneamine (a) and ketoimine (b) forms. Unlike compounds 2 the double bonds of the pyridine ring of compounds 7 and 8 were readily reduced with hydrogen. Thus, n‐alkanoyl Reissert compounds afford a convenient route to the corresponding benzopyrroco‐lines.
Synthesis of 3‐carboethoxy‐4,11‐dihydro‐11‐alkyl/phenyl‐4‐oxopyrimido[1,2‐b][1,2,4]benzothiadiazine 6,6‐dioxides. A novel heterocyclic ring system
Authors: Murthy M. S. R. , Nageswar Y. V. D. , Reddy A. V. Narender , Ramalingam T. , Sattur P. B. 
Published: March 2009

AbstractThe synthesis of some novel 3‐carboethoxy‐4,11‐dihydro‐11‐alkyl/phenyl‐4‐oxopyrimido[1,2‐b][1,2,4]benzo‐thiadiazine 6,6‐dioxides (IVa‐c) from 3‐amino‐4‐alkyl/phenyl‐4H‐1,2,4‐benzothiadiazine 1,1‐dioxides (1a‐c) and diethyl ethoxymethylenemalonate (II) is described. The compounds have been screened for their antibacterial activity.
Synthesis and in solution behaviour of new 2‐substituted‐4‐thiazolidinecarboxylic acid derivatives
Authors: Chiarino D. , Ferrario F. , Pellacini F. , Sala A. 
Published: March 2009

AbstractA number of 2‐substituted‐4‐thiazolidinecarboxylic acid derivatives were synthesized by cyclocondensation of L‐cysteine or its esters with various aldehydes, resulting from acids provided with antiinflammatory properties. In the cyclocondensation a new chiral center at C‐2 position of thiazolidine ring is formed giving rise to a mixture of diastereoisomers which can be partially separated. These diastereoisomers show in solution a fast epimerisation at the same chiral center as evidenced by 1H‐nmr studies.
Reactions of 2‐aminothiobenzamide with isocyanates: A new synthesis of 2, 3‐dihydroimidazo[1, 2‐c]quinazolin‐5(6H)‐one and 3, 4‐Dihydro‐2H‐pyrimido[1, 2‐c]quinazolin‐6(7H)‐one
Authors: Shiau Chia‐Yang , Chern Ji‐Wang , Tien Jung‐Hsiung , Liu Kang‐Chien 
Published: March 2009

Abstract2‐(2‐Chloroethylureido)‐ and 2‐(3‐chloropropylureido)thiobenzamides 5a, b were prepared in good yields by treating 2‐aminothiobenzamide with 2‐chloroethyl and 3‐chloropropyl isocyanates respectively. Subsequent treatment of compound 5a and 5b either with alkali or mineral acid led to the formation of 2, 3‐dihydro‐imidazo[1, 2‐c]quinazolin‐5(6H)‐one 7a and 3, 4‐Dihydro‐2H‐pyrimido[1, 2‐c]quinazolin‐6(7H)‐one 7b.
Thermally induced fragmentation and cyclisation of C‐azidohydrazones
Authors: Bruché Luca , Garanti Luisa , Zecchi Gaetano 
Published: March 2009

AbstractC‐Azidohydrazones 2 were synthesized from the corresponding C‐chlorohydrazones 1 and submitted to thermal decomposition in boiling benzene. Various kinds of products were obtained due to competitive modes of evolution of first‐formed nitrenes 13, namely hydrogen abstraction to form aminohydrazones 3 and benzotriazepine 8, and radical fragmentation to give ultimatively diaryls 4 and arylglyoxylate arylhydrazones 5. Ring‐closed products, namely 1, 2, 4‐triazoles 6 and imidazolones 7 were also formed.
Carbon‐13 nuclear magnetic resonance spectra of fentanyl analogs
Authors: Brine G. A. , Boldt K. G. , Huang P.‐T. , Sawyer D. K. , Carroll F. I. 
Published: March 2009

AbstractNatural abundance carbon‐13 chemical shifts are reported for the hydrochloride salts of fentanyl (1a) and fifteen analogs. The signals are assigned on the basis of chemical shift theory, SFORD multiplicities, signal intensities, comparisons with model compounds, and thiophene carbon‐proton coupling constants. In addition to its forensic value, the data suggest that the solution conformations of the analogs are similar to that of fentanyl hydrochloride.
Synthesis of new tricyclic ring systems containing the pyrimido[5, 4‐b][1, 4]oxazine skeleton
Authors: Mátyus Péter , Szalay Luca , Kasztreiner Endre , Jerkovich Gyula , Rabloczky György 
Published: March 2009

AbstractSynthesis of derivatives 4 and 6 of two novel tricyclic ring systems, 1, 2, 4‐triazolo[3, 4‐c]pyrimido[5, 4‐b]‐[1, 4]oxazine and imidazo[1, 2‐c]pyrimido[5, 4‐b][1, 4]oxazine, respectively is described. Although the parent pyrimido[5, 4‐b]oxazines possess positive inotropic activity, the tricyclic compounds are practically inactive.
Alkaline hydrolysis of 3‐methyl‐2H‐1, 3‐benzothiazinium iodides
Authors: Szabó János , Bernáth Gábor , Sohár Pál 
Published: March 2009

AbstractAlkaline hydrolysis of the 3‐methyl‐2H‐1, 3‐benzothiazinium iodide 5a and of its 4‐aryl derivatives 5b, c in the presence of hexacyanoferrate(III)ion resulted in the formation of 2, 2′‐diaryloxodiphenyl disulfides 6a‐c. In contrast, the 4‐benzyl derivative 5d underwent hydrogen iodide elimination to give the enamine 7. Mechanisms are proposed for the reactions.
Behaviour of aminoacids and aliphatic aldehydes in dipolar aprotic solvents: Formation of oxazolidinones—behaviour of aminoacids and aliphatic aldehydes in dipolar aprotic solvents
Authors: Orsini F. , Pelizzoni F. , Forte M. , Sisti M. , Bombieri G. , Benetollo F. 
Published: March 2009

AbstractReactions of aliphatic branched aldehydes with proline in dimethyl sulfoxide or acetonitrile solution afford oxazolidin‐5‐ones with high diastereoselection. Linear aldehydes afford aldolic/crotonic condensation products; with short reaction times, the presence of Oxazolidinones can be detected in the pmr spectra. Acyclic aminoacids and branched aldehydes yield a reaction mixture the pmr and ir spectra of which give evidence for iminic‐oxazolidinone equilibria. The structure of (2R,5S)‐2‐trichloromethyl‐1‐aza‐3‐oxabiciclo‐[3.3.0]octan‐4‐one has been confirmed by X‐ray diffraction analysis.
S,S'‐ and S,N‐disubstituted derivatives of 1,3,4‐thiadiazoledithiones
Authors: Katritzky Alan R. , Wang Zouquan , Offerman Rick J. 
Published: March 2009

AbstractFacile synthesis of 2‐n‐dodecylthio‐4‐phenylthiomethyl‐1,3,4‐thiadiazole‐5‐thione 6, starting from 2,5‐dimercapthothiadiazole via 2‐n‐dodecylthio‐1,3,4‐thiadiazole‐5‐thione 2, 2‐n‐dodecylthio‐4‐hydroxymethyl‐1,3,4‐thiadiazole‐5‐thione 4 and 2‐n‐dodecylthio‐4‐chloromethyl‐1,3,4‐thiadiazole‐5‐thione 5 is described.
The stereochemical investigation of 3‐Aryl‐4‐methyl‐1,2,3‐oxathiazolidine 2‐oxides using NMR
Authors: Nishiyama Tomihiro , Takahama Yasumitsu , Yamada Fukiko 
Published: March 2009

AbstractThe title compounds were prepared by the reaction of the corresponding N‐2‐hydroxyisopropylanilines with thionyl chloride in the presence of triethylamine, and their pmr and cmr spectra were examined. On the basis of the chemical shifts due to the γ‐ and δ‐effects, the stereochemical structures are discussed.
Mechanism of the cycloaddition‐elimination reactions of 4‐methyl‐5‐phenylimino‐δ2‐1,2,3,4‐thiatriazoline with alkyl and aryl isothiocyanates
Authors: L'Abbé Gerrit , Buelens Karin 
Published: March 2009

AbstractThe formation of thiadiazolidines 3a‐c and dithiazolidines 4a‐c and 5a‐b from the title reactions has been studied in detail under a variety of conditions. On the basis of kinetic measurements, isomerization studies and cross experiments a mechanism is proposed involving path (b) (Scheme 1) as the first step, followed by a series of isomerizations as shown in Scheme 3.
A facile synthesis of 3‐aryl‐4‐pyrazoleacetic acids and of their 4,5‐dihydro derivatives
Authors: Curzu Maria M. , Pinna Gérard A. , Barlocco Daniela , Cignarella Giorgio 
Published: March 2009

AbstractN‐1‐Unsubstituted‐3‐aryl‐4‐pyrazoleacetic acids and their 4,5‐dihydro derivatives can conveniently be prepared by cyclization of 3‐benzoyl‐3‐butenoic acids with hydrazine hydrate in acetic acid and subsequent treatment with bromine in acetic acid or, respectively, with diluted mineral acids.
Mass spectra of 3(2H)‐cinnolinone and 2‐substituted derivatives
Authors: Zey Robert L. , Gross Michael L. , Groenewold Gary S. 
Published: March 2009

AbstractThe mass spectrum of 3(2H)‐cinnolinone indicates that it undergoes fragmentation in a fashion similar to other heterocyclic systems containing two vicinal nitrogens. The initial fragmentation, loss of CO, gives a 1H‐indazole radical cation, as was shown by deuterium labelling and metastable ion spectra. Four 2‐substituted‐3(2H)‐cinnolinones were also studied and it was found that their fragmentation patterns are highly influenced by the substituent groups.
5‐Oxo‐1,4‐dihydroindenopyridines: Calcium modulators with partial calcium agonistic activity
Authors: Rose Ulrich 
Published: March 2009

AbstractThe title compounds 4a‐g were prepared by Knoevenagel reactions of 1,3‐indandione (1) with the aromatic aldehydes 2a‐g followed by cyclizing Michael addition of the products thus obtained with methyl β‐aminocrotonate (3). The structures of products 4 were characterized by spectal data. Positive inotropic activities were observed on electrically stimulated, left atria of giunea pigs and these effects could be attributed to calcium agonism. On the other hand, barium chloride‐induced contractions of guinea pig ileum were inhibited in a dose‐dependent manner.