bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of thiazoles from the reaction of phenyliodonium ylids of cyclic β‐dicarbonyl compounds with thioureas
Authors: Kamproudi Heleni , Spyroudis Spyros , Tarantili Petroula 
Published: March 2009

AbstractPhenyliodonium ylids of cyclic β‐dicarbonyl compounds react with substituted thioureas to form the corresponding thiouronium ylids. The latter, when they have one free amino group, are converted upon heating to fused thiazoles. The reaction can be considered as a modification of the Hantzsch synthesis.
Phenyliodonium derivatives from 4‐aminocoumarin and their reactivity
Authors: Papoutsis Ioannis , Spyroudis Spyros , Varvoglis Anastasios 
Published: March 2009

AbstractThe reaction of 4‐aminocoumarin with [hydroxy(tosyloxy)iodo]benzene affords 4‐amino‐3‐phenyliodoniocoumarin tosylate which upon basification is converted to the corresponding stable iodine‐nitrogen 1,4‐dipole. The reactivity of the latter is briefly discussed.
Radical mediated synthesis of 6‐arylphenanthridines via benzotriazole ring‐opening
Authors: Katritzky Alan R. , Yang Baozhen 
Published: March 2009

AbstractLithiation of diarylbenzotriazol‐1‐ylmethanes followed by addition of copper(I) iodide gave 6‐arylphenanthridine derivatives in moderate yields. When the two aryl groups were the same or contained very different electron densities, only one product was obtained. However, when the two aryl groups exhibited electron densities of similar magnitude, two isomers were afforded. According to the substituent effect, we believe that the reactions proceed via radical intermediates formed by copper(I) iodide.
Synthesis and reactions of 3‐aroyl derivatives of 4‐hydroxy‐2‐quinolones and 4‐hydroxycoumarin
Authors: Kappe Thomas , Schnell Barbara 
Published: March 2009

Abstract3‐Aroyl‐4‐hydroxy‐2‐quinolones 4 and 11 can be synthesized starting with 1 or 9 via Fries rearrangement of the corresponding esters 3 and 10, catalyzed by potassium cyanide and 18‐crown‐6. A one pot procedure is presented in which the esters do not need to be isolated. Reduction of the aryl ketones 4 and 11 with zinc dust leads to the benzyl derivatives 5 and 12. Reaction of the aryl ketones 4 and 11 with hydroxylamine and subsequent heating of the crude product leads via thermal Beckmann rearrangement and dehydration to oxazoloquinolones 7 and 14. 2‐Aroyloxypyrido[1,2‐a]pyrimidin‐4‐ones 17 and 20 could not be converted to the corresponding ketones by Fries rearrangement.
Diels‐alder adducts of a spirocyclopentenotriazoloazodienophile. Assignment of their 1H and 13C NMR spectra
Authors: Alexandrou N. E. , Mertzanos G. E. , Stephanidou‐Stephanatou J. , Tsoleridis C. A. 
Published: March 2009

Abstract1‐Phenyl‐cyclopenteno[1,2‐d]‐1,2,3‐rriazolo‐5‐spiro‐4′‐[perhydropyrazolino‐3′,5′‐dione] (5) afforded in situ, by oxidation with lead tetraacetate, the corresponding cyclopentenotriazolo‐spiropyrazolodione 6, which was trapped with dienes giving the hetero‐Diels‐Alder adducts 10–12 in good yields. The Diels‐Alder reactions were examined on the basis of AM1 MO calculations. Total assignment of the 1H‐ and 13C‐nmr chemical shifts as well as the relative configuration of these adducts was accomplished with the help of 2D (1H‐1H COSY, 1H‐1H NOESY, 1H‐13C XHCORR, 1H‐13C COLOC) and NOE difference spectroscopy. The structures of compounds 11a and 11b were also examined by molecular modeling.
Azido/tetrazole equilibrium in the thiazoloacridinone series
Authors: Hanoun Jean‐Pierre , Faure Robert , Galy Jean‐Pierre , Elguero José 
Published: March 2009

AbstractCompounds 2‐azido‐6H‐thiazolo[5,4‐a]acridin‐11‐one 3 and 2‐azido‐6‐butylthiazolo[5,4‐a]acridin‐11‐one 4 have been prepared for the first time. The azido/tetrazole equilibria of the most soluble compound 4 has been studied in six solvents. The resulting tautomeric equilibrium constants have been compared with those of 2‐azido‐4,5‐dimethylthiazole 1 and 2‐azidobenzothiazole 2. The rather insoluble NH derivative 3 when dissolved in DMSO contains 66% of tetrazole 3b while the corresponding anion (obtained by adding sodium hydride) is all in the tetrazole 13b form.
Synthesis of new imidazo[4,5‐d][1,3]diazepine derivatives from 5‐amino‐4‐(cyanoformimidoyl)imidazoles
Authors: Dias Alice M. , Fernanda M. , Proença J. R. P. , Booth Brian L. 
Published: March 2009

AbstractN1‐[(Z)‐2‐Amino‐1,2‐dicyanovinyl]formamidines 1a‐d react readily with tosyl isocyanate to form novel 8‐amino‐3‐substituted‐5‐oxo‐7‐tosylaminoimidazo[4,5‐d][1,3]diazepines 6a‐d rather than the 6‐cyano‐2‐oxopurine derivatives 5a‐d expected. Compound 5a has been synthesized from 1a by reaction with ethyl chloroformate and base‐catalyzed cyclization of the resultant 5‐ethoxycarbonylamino‐4‐(cyanoformimidoyl)imidazole. Treatment of the 5‐amino‐4‐cyanoimidazoles 7a and b with tosyl isocyanate under similar conditions gives the 4‐cyano‐5‐(3′‐tosylureido)imidazoles 8a and b, which on treatment with ethanolic ammonia cyclizes to the corresponding isoguanines 10a and b.
Synthesis of C‐nor‐heterocyclic steroid analogues
Authors: Esses‐Reiter Klára , Reiter József 
Published: March 2009

Abstract2‐Substituted‐amino‐10H‐thiazolo[5,4‐b]benz[e]indene derivatives 5 representing a novel ring system were synthesized. Their acylation led to exo‐acylated derivatives 9 that could be converted to the corresponding glycine analogues 12.
Synthesis and 13C, 15N NMR study of a new functionalized pyrido[2,3‐b]indole derivative
Authors: Buisson J.‐P. , Bisagni E. , Monneret C. , Demerseman P. , Leon C. , Platzer N. 
Published: March 2009

AbstractNew functionalized α‐carbolinones especially the 4‐hydroxy‐3‐nitro‐1H,9H‐pyrido[2,3‐b]indol‐2‐one were synthesized in a good yield, three‐step reaction. A complete 13C, 15N nmr study of this carbolinone and precursors is presented.
Alkylation and arylation at the C‐3′ side chain position of cephalosporins via a pummerer intermediate
Authors: Gourdoupis Christos G. , Stamos Ioannis K. 
Published: March 2009

AbstractThe Pummerer intermediate generated from a 3‐exomethylene‐1‐oxocephem with trifluoroacetic anhydride was trapped intermolecularly in the presence of a Lewis acid by some aromatic or olefinic nucleophiles.
Mechanistic studies in the reaction of 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione with 2,5‐dimethyl‐2,4‐hexadiene
Authors: Vassilikogiannakis Georgios , Stratakis Manolis , Karabatsos Gerasimos J. , Orfanopoulos Michael 
Published: March 2009

AbstractSecondary isotope effect measurements of methanol adducts from the reaction of 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione with 2,5‐dimethyl‐2,4‐hexadiene, support the formation of an aziridinium imide intermediate rather than an open dipolar intermediate in the rate determining step.
A trilactone related to anemonin
Authors: Stamos Ioannis K. , Cassady John M. 
Published: March 2009

AbstractTreatment of Anemonin sequentially with two equivalents of the anion 2 and iodine gave the monoalkylated monoiodinated iodolactone t‐butyl ester 3. Ester cleavage in anhydrous acedic media followed by treatment with sodium hydrogen carbonate transformed 3 to trilactone 4.
NMR analysis of restricted internal rotation in 2‐substituted‐2,3‐dihydro‐3‐o‐tolyl(chlorophenyl)‐4(1H)‐quinazolinones
Authors: Noto Renato , Gruttadauria Michelangelo , Meo Paolo Lo , Pace Andrea 
Published: March 2009

AbstractSteric interactions between aryl and heterocyclic moieties in 2‐substituted‐2,3‐dihydro‐3‐o‐tolyl(chlorophenyl)‐4(1H)‐quinazolinones 1a‐j produce sufficient restriction to rotation about the aryl CN bond that the presence of torsional isomers may be detected at room temperature. Diastereomeric population and free energy of activation for rotation have been calculated by 1H nmr spectra. Probably due to a preferred axial position of R2 substituent no dramatic variation both in A/B ratio and in ΔG≠ value has been observed for 1a‐f. The comparison between 1a and 1j ΔG≠ values allows to formulate a hypothesis on the structure of the transition state.
Synthesis and stereochemical studies of 6‐substituted 1H,3H,6H,7aH‐3,3‐dimethylimidazo‐[1,5‐c]thiazol‐5‐one‐7‐thiones
Authors: Györgydeák Z. , Kövér K. E. , Miskolczi I. , Zékány A. , Rantal F. , Luger R , Strumpel M. Katona 
Published: March 2009

AbstractThe reaction of (4S)‐5,5‐dimethyl‐4‐thiazolidine‐carboxylic acid 1 with alkyl and aryl isothiocyanates 2 gave bicyclic thiohydantoins 3. The (2R,4S)‐ and (2S,4S)‐mixtures of 2‐substituted 5,5‐dimethyl‐4‐thiazolidine‐carboxylic acids 4 and 8 containing two centers of chirality in the analogous reaction afforded thiohydantoins 7 and 10, respectively, with (1R)‐configuration. In some cases we managed to isolate the thioureido acid intermediates 6 and 9 or their triethylamine salts which afforded the corresponding bicycles 7 and 10 under thermal cyclization or acidification. The stereochemistry has been elucidated by high resolution ram studies, optical rotation measurements and X‐ray crystallography.
Synthesis and spectral properties of substituted [1,2,4]oxadiazolo[4,5‐a] [1,5] benzodiazepines
Authors: Cortés Eduardo CortÉS , Ambrosio Ana MarÍA Mendoza 
Published: March 2009

AbstractThe preparation of twelve novel substituted [1,2,4]oxadiazolo[4,5‐a][1,5]benzodiazepines which have potentially useful pharmacological properties; by 1.3‐dipolar cycloaddition of benzonitrile oxides, generated in situ from benzohydroxamoyl chloride and triethylamine, to 1,5‐benzodiazepine derivatives, is described. The structure of all products was corroborated by ir, 1H‐nmr, 13C‐nmr and ms.
Studies on pyrrolidinones. On the carbamoylation of some pyroglutamic derivatives
Authors: Cauliez Pascal , Fasseur Dominique , Couturier Daniel , Rigo BenoǏT , Kolocouris Antonios 
Published: March 2009

AbstractThe carbamoylation of some lactams derivatived from pyroglutamic acid as been studied; better yields were obtained starting from the unsubstitued lactam (toluene, 80°) rather than starting with the N‐silyllactam (room temperature), although these latter reaction conditions could be interesting for heat sensitive compounds. Methyl and phenyl isothiocyanate react only with the sodium salt of methyl pyroglutamate, giving 1,5‐diaddition products.
Reactivity of α‐acylated β‐enamino ketones and esters: Synthesis of pyrazoles
Authors: Missio Lauri J. , Braibante Hugo S. , Braibante Mara E. F. 
Published: March 2009

AbstractThe reactivity of the enamino compounds 4‐amino‐3‐phenylamino(thio)carbonyl‐3‐penten‐2‐one 1 and 2 and ethyl 3‐amino‐2‐phenylamino(thio)carbonyl‐2‐butyrate 7 and 8 was studied using the reaction with hydrazine hydrate and hydrazine hydrochloride to evaluate the 1,3 electrophilic center of the compounds by the formation of the pyrazole rings. The pyrazoles 3, 4, 5, 9, 11 and 13 were obtained depending on the reaction conditions employed.
The synthesis of 3‐bromo‐2,4,5‐trifluorobenzoic acid and its conversion to 8‐bromoquinolonecarboxylic acids
Authors: Renau Thomas E. , Sanchez Joseph R. , Domagala John M. 
Published: March 2009

AbstractA series of 8‐bromo‐4‐oxo‐3‐quinolinecarboxylic acids was prepared via the borate ester, 8. The key intermediate in the synthesis of the final products 10a‐10d was 3‐bromo‐2,4,5‐trifluorobenzoic acid (3), conveniently prepared in two steps from the known oxazoline, 1. The preparation of 10a‐10d is a significant improvement of the literature procedure currently available for the synthesis of these compounds.
Synthesis of heterocyclic bioregulators and semiochemicals
Authors: Mori Kenji 
Published: March 2009

AbstractChemistry and biology of oxygen heterocycles as insect pheromones are reviewed referring to exo‐brevicomin, disparlure, japonilure and olean. Synthesis of koninginin A, a microbial metabolite, is discussed. Two azetidine alkaloids, penaresidin A and penazetidine A, were synthesized.
Azadiene diels‐alder reactions: Scope and applications. Total synthesis of natural and Ent‐fredericamycin A
Authors: Boger Dale L. 
Published: March 2009

AbstractA review of our studies of the inverse electron demand Diels‐Alder reactions of heteroaromatic and acyclic azadienes is presented and the application of a N‐sulfonyl‐1‐aza‐1,3‐butadiene [4+2] cycloaddition reaction in the total synthesis of natural and ent‐fredericamycin A is described in detail.
Rearrangement reactions of aziridinylbenzaldoximes
Authors: Johnson James E. , Nwoko Delphine , Hotema Martha , Sanchez Natalia , Alderman Reidun , Lynch Vincent 
Published: March 2009

AbstractReactions of 2,2‐dimethylaziridine with benzohydroximoyl chlorides [ArC(Cl)NOH] give aziridinylbenzaldoximes 1. It has been found that the aziridine ring in these compounds undergoes ring opening in hydrogen chloride‐dioxane solution to give (Z)‐N‐hydroxy‐N′‐(2‐chloro‐2‐methylpropyl)benzenecarboximidamides [ArC(NHCH2CR1R2Cl)NOH, 4]. Treatment of 1 with hydrochloric acid followed by neutralization with aqueous sodium hydroxide gave 6,6‐dimethyl‐3‐aryl‐1,2,4‐oxadiazines 2. Reaction of 4 with sodium hydride in dioxane gave 5‐isopropyl‐3‐aryl‐4,5‐dihydro‐1,2,4‐oxadiazoles 5. Reaction of the 4,5‐dihydro‐1,2,4‐oxadiazoles 5 with N‐chlorosuccinimide gave the heteroaromatic 1,2,4‐oxadiazoles 6. It is suggested that reactions of 4 with sodium hydride in dioxane solution involve the conjugate base of 4 which undergoes a 1,2‐hydride shift that is concerted with loss of chloride ion. In aqueous sodium hydroxide solution it is suggested that the conjugate base of 4 undergoes ionization of the chlorine atom followed by nucleophilic attack by the oximate anion.
Preparation and characterization of tetraaza[14]annulene and its nickel(ii) and copper(II) complexes with crown ether functionalities
Authors: Sakata Kazunori , Shimoda Manabu , Hashimoto Mamoru 
Published: March 2009

AbstractThree new organic hosts are described that contain a tetraaza[14]annulene core to which two crown ether voids are attached. These hosts include a free base tetraaza[14]annulene and/or its complexes with benzo‐15‐crown‐5 rings. The crown tetraaza[14]annulene is synthesized from tetraaza[14]annulene and 4′‐chloroformylbenzo‐15‐crown‐5. Its nickel(II) and copper(II) complexes are prepared in a similar manner as above. In solution the compounds do not tend to form aggregates. However, aggregation is affected by the presence of alkali‐metal salts, which coordinate to the crowns. Li+ and Na+ cations with diameters that match the diameters of the crown ether rings form 1:2 host‐guest complexes. Complexes with 2:2 host‐guest stoichiometry are formed when the diameters of K+ and Cs+ cations exceed that of the crown ether rings. Nevertheless, it is weak for the present macrocycle and its complexes to be inclined to form dimers owing to the steric hindrance of the substituent groups and owing to restraining the rotation of the carbonyl bond connecting the crown ether group.
Synthesis of 2‐aryl‐4‐hydroxy‐5‐thio substituted 1,3‐thiazin‐6‐ones via sulfenylation of 2‐aryl‐4‐hydroxy‐[1,3]thiazin‐6‐ones with sulfenyl chlorides
Authors: Prasad J. V. N. Vara 
Published: March 2009

AbstractA series of 2‐aryl‐4‐hydroxy‐5‐thio substituted 1,3‐thiazin‐6‐ones were synthesized for human immunodeficiency virus‐1 protease inhibition. These compounds were synthesized by the treatment of 4‐hydroxy‐5‐thio substituted‐1,3‐thiazin‐6‐ones with the corresponding sulfenyl chlorides. The products were obtained in good isolated yields, inspite of the presence of bulkyl substitutents at the ortho position of phenyl sulfenyl chloride portion.
Synthesis of novel 5‐hydroxy‐3‐alkoxy‐ and 5‐hydroxy‐3‐alkylthioindole‐2‐carboxamides
Authors: Unangst Paul C. , Connor David T. , Miller Steven R. 
Published: March 2009

AbstractThe preparation of several novel 5‐hydroxyindole‐2‐carboxamides is described. A 5‐benzyloxyindole ester was elaborated to the 3‐bromo, 3‐hydroxy, and 3‐alkoxy ester intermediates followed by conversion to the amide and debenzylation. A related 5‐acetyloxy indole ester was converted to 3‐sulfinyl and 3‐alkylthio intermediates before simultaneous amidation and removal of the 5‐hydroxy protecting group.
4‐Cyano‐2‐oxo‐1,2,4‐oxadiazolo[2,3‐a]quinoxaline 5‐N‐oxides. New synthetic method and reaction with alcohols. Potential cytotoxic activity
Authors: Martínez Crespo F. J. , Palop J. A. , Sainz Y. , Narro S. , Senador V. , González M. , De Ceráin A. López , Monge A. , Hamilton E. , Barker A. J. 
Published: March 2009

AbstractSeveral quinoxaline 1,4‐di‐N‐oxides have been shown to be efficient and selective cytotoxins for hypoxic cells. We present now a series of 4‐cyano‐2‐oxo‐1,2,4‐oxadiazolo[2,3‐a]quinoxaline 5‐N‐oxides 2a‐2k. They were prepared starting from 3‐amino‐2‐quinoxalinecarbonitrile 1,4‐di‐N‐oxides 1a‐1k and 2‐chloroethyl isocyanate in dry dioxane at 100–110°. A reaction mechanism is proposed. The treatment of 1a with phenyl isocyanate afforded 2a. Reaction of 2c with silica gel yielded 1c. Compounds 2a‐2g were heated in the presence of ethanol and 2‐propanol giving the corresponding carbamates 3a‐3g and 4a‐4g. Compound 2d was already obtained by heating a mixture of 1d and ethyl chloroformiate. Compound 2b was prepared when the carbamate 3b was heated at 150°. Quinoxalines were tested as cytotoxic agents both in oxic and hypoxic cells. The most interesting compounds were 3g and 4g.
Further studies on heterocyclic arene imines. Preparation of 1a,9b‐dihydroazirino[f][1,7]phenanthroline, 3b,4a‐dihydroazirino‐[2,3]phenaleno[1,9‐g,h]quinoline and 1a,13b‐dihydrodibenzo[1,2:6,7]phenazino[1,2‐b]azirine
Authors: Bazanov‐Katz Nina , Zangi Ronen , Blum Jochanan 
Published: March 2009

AbstractThe syntheses of the K‐imine derivatives of 1,7‐phenanthroline, phenaleno[1,9‐g,h]quinoline, and dibenzo[a,h]phenazine are described. The parent heterocyclic compounds 4, 9 and 14 were oxidized to the corresponding K‐oxides, 5, 10 and 15, which in turn were reacted with sodium azide in aqueous acetone. The resulting trans‐azido alcohols were then cyclized with tributylphosphine to the title compounds 6, 11 and 16.
Pyirolothieno[1,4]diazepines. Part IV. First synthesis of pyrrolo‐[1,2‐a]thieno[2,3‐f][1,4]diazepine Derivatives
Authors: Boulouard Michel , Dallemagne Patrick , Alsaïdi Abdellah , Rault Sylvain 
Published: March 2009

AbstractTreatment of 3‐(2‐formyl‐1H‐pyrrol‐1‐yl)‐2‐thiophenecarboxamide by various nucleophiles like methyl ketones, amines, alcohols, thiols or acetates led to new 5,6‐dihydro‐4H‐pyrrolo[1,2‐a]thieno‐[2,3‐f][1,4]diazepines.
Iminium carbonic acid derivative salts. X. Synthesis of N,S‐containing heterobicycles from N‐protected 2‐methylthio‐1,3‐thiazinium and 2‐methylthiothiazolium salts. Part 2. Reaction of N‐protected 2‐methylthio‐1,3‐thiazinium and 2‐methylthiothiazolium salts with vinylogous CH‐acidic compounds
Authors: Hanefeld Wolfgang , Naeeni Mahmoud , Schlitzer Martin 
Published: March 2009

AbstractN‐Boc‐protected 2‐methylthio‐1,3‐thiazinium 3 and 2‐methylthiothiazolium salts 4,7 obtained from the corresponding 1,3‐thiazine‐2‐thiones and thiazolidine‐2‐thiones by the action of methyl iodide or trimethyloxonium tetrafluoroborate were reacted with vinylogous CH‐acidic compounds forming ketene N,S‐acetals 5,6,8,9. The protection group was removed with trifluoroacetic acid whereupon the desired cyclisation to pyrido[2,1‐b]‐1,3‐thiazines 10 and thiazolo[3,2‐b]pyridines 11,12 took place.
Photocyclization reactions. Part 5. Synthesis of dihydrobenzofuranols using photocyclization of 2‐alkoxybenzophenones and ethyl 2‐benzoylphenoxyacetates
Authors: Sharshira Essam Mohamed , Shimada Satoru , Okamura Mutsuo , Hasegawa Eietsu , Horaguchi Takaaki 
Published: March 2009

AbstractPhotocyclization reactions were carried out on 2‐alkoxybenzophenones 1a‐h and ethyl 2‐benzoylphenoxyacetates 2a‐e in acetonitrile. Irradiation of 1a‐h gave dihydrobenzofuranols 4a‐h in 68–84% yields. Similarly, irradiation of 2a‐e afforded dihydrobenzofuranols 8a‐e in 72–75% yields. Ethyl acrylates 9b‐c were also produced in 6–8% yields from photoreactions of 2b‐c. Substituent effects on cyclization of 1,5‐biradical intermediates and reaction pathways are discussed. Benzophenones are useful compounds to prepare dihydrobenzofuranols by photocyclization.
Synthesis of 10‐amino‐1,2,3,4‐tetrahydrobenzo[b][1,6]‐naphthyridines and related derivatives
Authors: Gatta Franco , Giudice Maria Rosaria Del , Mustazza Carlo 
Published: March 2009

AbstractThis paper describes the synthesis of some 10‐amino‐1,2,3,4‐tetrahydrobenzo[b][1,6]naphthyridines and of the new 13‐amino‐6,6a,7,8,9,10‐hexahydro‐12H‐benzo[b]pyrido[1,2‐g][1,6]naphthyridines starting from isatins and 4‐piperidones or quinolizidin‐2‐one.
Aroylation of 5‐amino‐2H‐1,2,4‐thiadiazolin‐3‐one
Authors: Cho Nam Sook , Ra Chan Soo , Ra Do Young , Song Jin Soo , Kang Sung Kwon 
Published: March 2009

Abstract2‐Aroyl‐5‐aroylamino‐1,2,4‐thiadiazolin‐3‐ones 2 have been synthesized through aroylation of 5‐amino‐2H‐1,2,4‐thiadiazolin‐3‐one (1) as an analog of cytosine. The aroylation was carried out with a substituted aroyl chloride in pyridine at 56–58°. It has been established that the intermediates of the reactions are 2‐aroyl‐5‐amino‐1,2,4‐thiadiazolin‐3‐ones 3 on the basis of the spectral data, additional experimental information and ab initio molecular orbital calculations.
Proton, carbon‐13 and fluorine‐19 NMR studies of 9,10,11,12‐tetra‐fluoro‐5,6‐dihydrobenzo[b]naphth[2,1‐f]oxepin: ‘Through‐space’ carbon‐fluorine coupling was revealed
Authors: Jones Claude R. , Parlow John J. , Schnur Dora M. 
Published: March 2009

AbstractThe 1H, 13C and 19F nmr spectra of 9,10,11,12‐tetrafluoro‐5,6‐dihydrobenzo[b]naphth[2,1‐f]oxepin (1) were totally assigned using a combination of two‐dimensional nmr techniques. Unequivocal interpretation of the spectral data allowed the complete assignments of the resonances. In addition, the spectra of compound 1 revealed an unusual through‐space carbon‐fluorine coupling which was further supported by NOE and modeling experiments.
Synthesis of 9‐[(2‐hydroxy‐1‐phosphonylethoxy)ethyl]guanine, 1‐[(2‐hydroxy‐1‐phosphonylethoxy)ethyl]cytosine and 9‐[(2‐hydroxy‐1‐phosphonylethoxy)ethyl] adenine
Authors: Kim Dae‐Kee , Gam Jongsik , Kim Key H. 
Published: March 2009

AbstractThe acyclic nucleoside phosphonate analogues, 9‐[(2‐hydroxy‐1‐phosphonylethoxy)ethyl]guanine 6, 1‐[(2‐hydroxy‐1‐phosphonylethoxy)ethyl]cytosine 7 and 9‐[(2‐hydroxy‐1‐phosphonylethoxy)ethyl]adenine 8, have been prepared by the coupling of a tosylate of the phosphonate side chain 12 with a purine or pyrimidine base followed by deprotection of the blocking groups.
Synthesis of thiazole‐containing polyethers
Authors: Kwon Il‐Chun , Koh Young Kook , Choi Jun‐Hyeak , Kim Hong‐Seok 
Published: March 2009

AbstractThiazole‐containing polyether podands were prepared from the reactions of hydroxymethylthiazole derivatives with di‐p‐tosylates of corresponding tri, terra, pentaethylene glycols in the presence of potassium hydride.
Characterization and differentiation of heterocyclic isomers. Part 3. Study of high internal energy ions produced by electron ionization mass spectrometry on 3‐methyl‐1,2‐ and 2‐methyl‐1,3‐thiazolopyridines
Authors: Giorgi Gianluca , Salvini Laura , Ponticelli Fabio , Tedeschi Piero 
Published: March 2009

AbstractThe eight members of two classes of heterocyclic isomers, namely 3‐methyl‐1,2‐, 1a‐d and 2‐methyl‐1,3‐thiazolopyridines 2a‐d have been characterized by mass spectrometry under electron ionization. High internal energy ions formed in the source have been studied by low and high resolution mass spectrometry.The data show remarkable differences among the various components of each class depending on the position of the nitrogen in the pyridine ring. Furthermore, by comparing the mass spectra of members of series 1 with those of their corresponding isomers belonging to series 2, it is still possible to obtain evidence for different behaviors in the fragmentation pathways. It seems to exclude the occurrence of inter‐conversion phenomena from one isomer into another, as well as conversion to a common intermediate before fragmentation. This also suggests that each member of series 1 and 2 retains its own structure after electron ionization.The data obtained on a double focusing instrument equipped with electrostatic and magnetic analyzers have been compared with those obtained on a mass spectrometer with an ion trap as the analyzer.