bluuebunny/crossref_metadata_2025_split huggingface dataset:
Total assignment of the 1H and 13C NMR spectra of benzo[f][1]benzothieno[2,3‐c]quinoline by inverse‐detected two‐dimensional NMR techniques
Authors: Shockcor John P. , Crouch Ronald C. , Martin Gary E. , Cherif Abdallah , Luo Jiann‐Kuan , Castle Raymond N. 
Published: March 2009

AbstractThe proton and carbon nmr spectra of benzo[f][1]benzothieno[2,3‐c]quinoline have been totally assigned using a combination of 2D nmr methods including concerted use of HMQC (heteronuclear multiple quantum correlation) and HMBC (heteronuclear multiple bond correlation) experiments.
An unusual reaction at C‐3 of 4‐methoxy‐6‐methyl‐2‐pyrone
Authors: Moreno‐Mañas M. , Pleixats R. 
Published: March 2009

AbstractTriacetic acid lactone methyl ether, 4, can be lithiated at C‐3 under kinetically controlled conditions. Further reaction with (E)‐2‐methyl‐3‐(4‐nitrophenyl)propenal results in an unusual condensation at C‐3.
Synthesis and NMR study of 9′‐substituted spiroindolinonaphthoxazine derivatives
Authors: Kakishita Tomonari , Matsumoto Kiyoichi , Kiyotsukuri Tsuyoshi , Matsumura Kenji , Hosoda Masahiro 
Published: March 2009

AbstractA photochromic spiroindolinonaphthoxazine derivative, 1,3,3‐trimethyl‐9′‐hydroxy‐spiro[indoline‐2,3′(3H)‐ naphtho[2,1‐b][1,4]oxazine] 3 was synthesized by condensation of 1,2,3,3‐tetramethylindolenium iodide 1 and l‐nitroso‐2,7‐dihydroxynaphthalene 2. Further, two new derivatives, 5 and 7, were prepared in good yields by the reactions of 3 with the hexafluoropropene trimer 4 and 4‐[perfluoro(2‐isopropyl‐1,3‐dimethyl‐1‐butenyl)‐oxybenzoyl chloride 6, respectively. Their unique structural features and property are discussed based on 1H‐, 13C‐ and 19F nmr spectral data.
C‐2 Arylamino substituted purineara‐carbocyclic nucleosides as potential anti‐cytomegalovirus agents
Authors: Koga Masakazu , Schneller Stewart W. 
Published: March 2009

AbstractThere are reports in the literature that placement of an arylamino side chain at the C‐2 position of purine nucleosides produces compounds capable of inhibiting DNA polymerase. To evaluate the potential of this class of compounds as antiviral agents that act by inhibiting viral DNA polymerase,ara‐carbocyclic purine nucleosides possessing a 4‐(l‐butyl)phenylamino and a 3,5‐dichlorophenylamino substituent at C‐2 were chosen as the prototype structures and have been prepared from 2,4,6‐trichloropyrimidine in 6 steps. For the antiviral analysis, human cytomegalovirus served as the principal virus since it expresses a virally specific DNA polymerase. None of the compounds showed activity towards this virus, but they were found to display some toxicity towards one or more cell lines.
Synthesis of fluoro and trifluoromethyl derivatives of 2‐phenylquinolin‐4‐ol
Authors: Janda Lubomir , Nguyen Johnny , Patterson Steven E. , Strekowski Lucjan 
Published: March 2009

AbstractA tert‐butoxide base‐mediated cyclization of fluoro‐ and trifluoromethyl‐substituted Schiff bases 12‐19 produces 4‐tert‐butoxyquinolines 23‐30 which are hydrolyzed to quinolin‐4‐ols 31‐38.
Synthesis of trans‐thienyl‐3‐ethoxycarbonyl‐2,3‐dihydro[1,5]benzothiazepin‐4(5H)‐ones
Authors: Letois Bertrand , Lancelot Jean Charles , Saturnino Carmela , Robba Max , De Caprariis Paolo 
Published: March 2009

AbstractA series of trans‐thienyl‐3‐ethoxycarbonyl‐2,3‐dihydro[1,5]benzothiazepin‐4(5H)‐ones 6‐8 was synthesized from thienylmethylidenemalonates 3a‐3c and 2‐aminobenzenethiol 3d in the presence of triethylamine hydrochloride at 160°. The [1,5]benzothiazepines 6‐8 were alkylated using 2‐dimethylaminochloroethane, 3‐dimethylaminochloropropane and 3‐(N‐piperidino)chloropropane in order to obtain the corresponding 5‐aminoalkylbenzothiazepinones 9‐14.
Pyrimidine derivatives. IX. Synthesis of bromosubstituted 5‐nitro‐2,4(1H,3H)‐pyrimidinedione derivatives
Authors: Kinoshita Toshio , Watanabe Yukihiro , Nakao Setsuko , Furukawa Sunao 
Published: March 2009

AbstractThe following 5‐nitro‐2,4(1H,3H)‐pyrimidinediones possessing bromo substituted side chains at the 1‐ and 6‐positions were prepared by bromination of 3,6‐dimethyl‐1‐(ω‐hydroxyalkyl)‐5‐nitro‐2,4(1H,3H)‐pyrimidinediones 4a and 4b and its nitrates 2a and 2b. The three of mono‐bromo derivatives are: 1‐(ω‐acetoxyalkyl and ω‐hydroxyalkyl)‐6‐bromomethyl‐3‐methyl. 6a, 6b, 7a and 7b and 1‐(ω‐bromoalkyl)‐3,6‐dimethyl‐2,4(1H,3H)‐ pyrimidinediones 8a and 8b. The one type dibromo derivatives are: 1‐(ω‐bromoalkyl)‐6‐bromomethyl‐3‐methyl‐2,4(1H,3H)‐pyrimidinediones 5a and 5b.
A new diene, 2‐methoxy‐1,3‐pentadiene‐5‐ol. Synthesis and intramolecular diels‐alder reactions
Authors: Jørgensen Tine , Nielsen Helle Chris , Malhotra Nageshwar , Becher Jan , Begtrup Mikael 
Published: March 2009

AbstractReactions of the diene 1‐benzyloxy‐2‐methoxy‐1,3‐pentadiene‐5‐ol in intramolecular Diels‐Alder reactions using maleic anhydride or fumaric acid ethyl ester is described. The new reactive diene is prepared starting from 3‐methoxypyridine. The structure of the diene was elucidated by a NOE nmr experiment.
Nitroimidazoles X. Syntheses of substituted 2‐(1‐methyl‐5‐nitro‐2‐imidazolyl)quinolines
Authors: Shafiee A. , Parang K. , Khazan M. , Ghasemian F. 
Published: March 2009

AbstractReduction of substituted‐2‐nitrobenzaldehyde (1) afforded substituted‐2‐aminobenzaldehyde (2). Reaction of compound 2 with 2‐acetyl‐1‐methyl‐5‐nitroimidazole (3) under basic conditions afforded substituted 2‐(1‐methyl‐5‐nitro‐2‐imidazolyl)quinolines 4. Reaction of compound 4 (R = X) with hydrogen peroxide in acetic acid afforded compound 5 which was transformed to compound 6 with phosphorus oxychloride.
Synthesis of 4,5‐dihydro‐1H,3H‐thieno[3,4‐c]thiophene and 4,5‐dihydro‐1H,3H‐thieno[3,4‐c]furan
Authors: Ripoll Jean‐Louis , Vallée Yannick , Khalid Mohamed , Hakiki Abdelhak 
Published: March 2009

Abstract4,5‐Dihydro‐1H,3H‐thieno[3,4‐c]thiophene and 4,5‐dihydro‐1H,3H‐thieno[3,4‐c]furan were synthesized by retro Diels‐Alder reactions under flash vacuum thermolysis conditions.
The HMQC‐NOESY experiment without decoupling during acquisition for detection of nOe between pseudo‐equivalent protons
Authors: Castle Lyle W. , Johnston Milton D. , Camoutsis Charalampos L. , Castle Raymond N. 
Published: March 2009

AbstractThe pseudo‐symmetric structure of benzo[f]phenanthro[9′,10′:4,5]thieno[2,3‐c]quinoline causes overlap of the resonances corresponding to H1 and H15 and also those of H11 and H12. We report here the observation of nOe between these pseudo‐equivalent protons using the HMQC‐NOESY experiment acquired without decoupling during acquisition.
Structural study of 3‐methyl‐2,4‐diphenyl‐3‐azabicyclo[3.3.1]nonan‐9β‐ol
Authors: Iriepa I. , Gil‐Alberdi B. , Galvez E. , Torres R. , Gomez‐Sal P. , Bellanato J. 
Published: March 2009

AbstractThe infrared spectra in several media and the crystal structure of 3‐methyl‐2,4‐diphenyl‐3‐azabicyclo[3.3.1]‐nonan‐9β‐ol (I) (Scheme I) have been determined, in order to complete the structural study described for the title compound from the 1H and 13C nmr data [1]. The bicyclic system adopts a flattened chair‐chair conformation in which the cyclohexane ring is more flattened. The methyl and phenyl groups are in equatorial positions and the OH group in an axial position with respect to the piperidine ring.
A short and general synthesis of 1,3‐dihydro‐6‐heteroaryl‐5‐perfluoroalkyl‐2H‐imidazo[4,5‐b]pyridin‐2‐ones
Authors: Kuo Gee‐Hong , Bacon Edward R. , Singh Baldev , Eissenstat Michael A. , Lesher George Y. 
Published: March 2009

AbstractTrifluoro or pentafluoroacylation of heteroaryl‐enamines 2a,b gave the corresponding perfluoroacylated heteroaryl‐enamines 3a‐c. Heating the latter compounds with diethyl iminomalonate gave 2‐amino‐3‐pyridinecarboxylates 4a‐c. Hydrolysis to the free acids 5a‐c, and reaction with diphenylphosphoryl azide afforded the desired 1,3‐dihydro‐6‐heteroaryl‐5‐perfluoroalkyl‐2H‐imidazo[4,5‐b]pyridin‐2‐ones 6a‐c.
In situ vinylindole synthesis. Diels‐alder reactions with maleimides to give tetrahydrocarbazoles
Authors: Noland Wayland E. , Walhstrom Mary J. , Konkel Michael J. , Brigham Mark E. , Trowbridge Annette G. , Konkel Lisa M. C. , Gourneau Ronald P. , Scholten Cheryl A. , Lee Nina H. , Condoluci John J. , Gac Todd S. , Pour Mehrdad Mostafaei , Radford Peter M. 
Published: March 2009

AbstractTetrahydrocarbazoles have been prepared in one‐flask syntheses from indoles, ketones or aldehydes, and maleimides, with acid catalysis. The reactions involve a condensation of the indole with the ketone or aldehyde, followed by an in situ trapping of the vinylindole in a Diels‐Alder addition with a maleimide. Isomerization of the double bond into the indole nucleus gave the tetrahydrocarbazoles which were isolated (6, 9, and 10). Variation of the indole, carbonyl compound, and maleimide has been explored. The predominant stereochemistry of the tetrahydro ring in the products is all‐cis, although a second stereoisomer has been isolated. Two regioisomers were generated from all unsymmetrical 2‐alkanones, except 2‐butanone, which gave the single isomer 9a. Aromatization of tetrahydrocarbazoles 6 to carbazoles 7 was accomplished with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone.
Cyclocondensation of α‐hydroxyimino‐β‐alkyl/arylimino‐β‐methylthioketones with hydrazine hydrate: Synthesis of 3(5)‐aryl‐5(3)‐alkyl/arylamino‐4‐nitroso (or amino) pyrazoles
Authors: Chakrasali R. T. , Srinivasa Rao Ch. , Ila H. , Junjappa H. 
Published: March 2009

AbstractThe title pyrazoles were synthesized through cyclocondensation of hydroxyiminoimine derivatives 1a‐j with hydrazine hydrate.
Naphth[1,2‐d]oxazole intermediates in the preparation of 3‐hydroxy‐4‐(1‐alkyl‐3‐methyl‐5‐hydroxy‐4‐pyrazolyl)‐azo‐1‐naphthalenesulfonamide dyes
Authors: Katritzky Alan R. , Rachwal Bogumila , Rachwal Stanislaw , Macomber David , Smith Terrance P. 
Published: March 2009

AbstractAcylation of 4‐amino‐3‐hydroxy‐1‐naphthalenesulfonic acid (3) with benzoyl chloride in pyridine gave pyridinium 3‐hydroxy‐4‐(N‐benzoylamino)‐1‐naphthalenesulfonate (12) which was converted by thionyl chloride followed by diethylamine into N,N‐diethyl‐2‐phenylnaphth[1,2‐d]oxazole‐5‐sulfonamide (14). The naphthoxazole moiety was hydrolyzed with potassium hydroxide and the resulting N,N‐diethyl‐4‐amino‐3‐hydroxy‐1‐naphthalenesulfonamide (11) coupled with 1‐alkyl‐3‐methyl‐5‐pyrazolones. The 2‐phenylnaphth[1,2‐d]oxazole intermediates and various by‐products were investigated.
Flavonoids. 43 [1,2]. Deprotonation‐initiated aryl migration with sulfur dioxide extrusion: A route to 2,3‐dihydro‐2,3‐diaryl‐3‐hydroxy‐4H‐1‐benzopyran‐4‐ones
Authors: Patonay Tamás , Hegedüs László , Patonay‐Péli Erzsébet 
Published: March 2009

AbstractTreatment of trans‐2,3‐dihydro‐2‐aryl‐3‐nosyloxy‐4H‐1‐benzopyran‐4‐ones with various bases afforded 2,3‐dihydro‐r‐2‐aryl‐t‐3‐hydroxy‐c‐(4‐nitrophenyi)‐4H‐1‐benzopyran‐4‐ones in a deprotonation‐initiated aryl migration followed by sulfur dioxide extrusion. In the presence of hydroxide and methoxide ions a secondary ring cleavage has also been observed. However, the reaction of trans‐2,3‐dihydro‐2‐aryl‐3‐nosyloxy‐4H‐1‐benzopyran‐4‐ones with cyanide ions gave 2,3‐dihydro‐r‐2‐aryl‐t‐4‐cyano‐c‐3,c4‐epoxy‐4H‐1‐benzopyrans in a carbonyl attack of cyanide followed by an internal substitution reaction.
Cyclocondensation reaction of 1,2‐diamino‐4‐methylbenzene and p‐substituted acetophenones
Authors: Insuasty Braulio , Abonia Rodrigo , Quiroga Jairo , Meier Herbert 
Published: March 2009

Abstract1,2‐Diamino‐4‐methylbenzene 1 reacts in the presence of sulphuric acid with 4‐substituted acetophenones 2a‐e yielding 2,4‐diaryl‐2,3‐dihydro‐2,8‐dimethyl‐1H‐1,5‐benzodiazepines 3a‐e and as minor component 2,4‐diaryl‐2,3‐dihydro‐2,7‐dimethyl‐1H‐1,5‐benzodiazepines 4a‐e. The ratio 3:4 is in the range of 7:3. The structure determination of the regioisomers was performed by NOE measurements.
Reactions of 6‐thiotheophylline with alkylating agents and epichlorohydrin: Isolation of S‐alkylated 6‐thiotheophylline and 7‐(2,3‐thioepoxypropyl)theophylline
Authors: Hayashi Hiroaki , Suzuki Fumio , Yasuzawa Toru , Ueno Hideo 
Published: March 2009

AbstractAlkylation of 6‐thiotheophylline (1) under the aprotic basic condition affords S‐alkylated 6‐thiotheophylline (3) together with an N7 ‐alkylated product 4. There is a tendency that the more reactive the alkylating agents are, the higher the yields of S‐alkylated products are. On the other hand, treatment of 6‐thiotheophylline (1) with epichlorohydrin afforded an unexpected product, 7‐(2,3‐thioepoxypropyl)theophylline (6), neither an S‐alkylated compound 3g nor an N7 ‐alkylated compound 4g. The chemical structure was determined by nmr spectroscopic analysis.
Synthesis of perhydropyrazino[1,2‐d][1,4]diazepine, a new heterocyclic compound
Authors: Gubert S. , Braojos C. , Anglada L. , Bolós J. , Sacristán A. , Ortiz J. A. 
Published: March 2009

AbstractA novel heterocycle, perhydropyrazino[1,2‐d][1,4]diazepine, is prepared in good yield by an efficient method starting from facile available compounds.
Alkali metal mediated conversion of arene oxides and arene imines into aromatic hydrocarbons
Authors: Elmalak Omar , Rabinovitz Mordecai , Blum Jochanan 
Published: March 2009

AbstractK‐Region oxides and imines of phenanthrene, chrysene benz[a]anthracene, and dibenz[a,h]anthracene react in tetrahydrofuran with lithium and sodium to give the parent hydrocarbons. In the presence of excessive metal, the latter are converted into dianions from which the parent compounds can be regenerated upon quenching with oxygen. Metalate derivatives of the oxides and imines are proposed to be the corresponding reaction intermediates in the deoxygenation and deamination processes.
Condensed as‐triazines. Synthesis of 7‐aryl‐8H‐[1,4]thiazino[2,3‐e]‐1,2,4‐triazin‐3(2H)‐one
Authors: Lee Kuan‐Han , Huang Bor‐Ruey , Chen Yeh‐Long , Wei Dau‐Chang , Tzeng Cherng‐Chyi 
Published: March 2009

AbstractRing closure of 6‐amino‐3‐oxo‐as‐triazine‐5‐thione with α‐haloketones provides the thiazino[2,3‐e]‐1,2,4‐triazines which dehydrate via an unusual pathway to give 7‐aryl‐8H[1,4]thiazino[2,3‐e]‐1,2,4‐triazin‐3(2H)‐ones.
The diels‐alder reaction of 5‐aminopyrazole‐4‐carbonitrile with dmad: Synthesis and structural determination of dimethyl 2‐(p‐toluenesulfonylamino)‐3‐cyano‐4‐imino‐1,4‐dihydropyridine‐5,6‐dicarboxylate
Authors: Tominaga Yoshinori , Castle Raymond N. , Kent Dalley N. 
Published: March 2009

AbstractThe Diels‐Alder reaction of 5‐amino‐1‐(p‐toluenesulfonyl)pyrazole‐4‐carbonitrile with dimethyl acetylenedi‐carboxylate was carried out in the presence of potassium carbonate in dimethyl sulfoxide. The reaction gave dimethyl 2‐(p‐toluenesulfonylamino)‐3‐cyano‐4‐imino‐1,4‐dihydropyridine‐5,6‐dicarboxylate. The product was formed by transformation of the original Diels‐Alder adduct followed by rearrangement of the p‐toluenesul‐fonylamino group into the 2‐position of the pyridine ring. The structure of the product was irrefutably established by X‐ray crystallography. This reaction is the first example of a pyrazole ring serving as the diene in a [4 + 2] cycloaddition reaction.
The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 13. Dibenzo‐[f,h]phenanthro[9′,10′:4,5]thieno[2,3‐c]quinoline
Authors: Luo Jiann‐Kuan , Castle Raymond N. 
Published: March 2009

AbstractThe synthesis of a previously unknown polycyclic heterocyclic ring system, dibenzo[f,h]phenanthro‐[9′,10′:4,5]thieno[2,3‐c]quinoline (4), was accomplished via photocyclization of the appropriate amide followed by chlorination. Substitution of the chlorine atom with hydrazine followed by removal of the hydrazine moiety with 10% copper sulfate solution afforded the parent ring system 4. The unequivocal assignment of its highly congested 1H and 13C spectra was accomplished by utilizing two‐dimensional nmr methods.
Synthesis of monoalkenylated crown ethers and C‐pivot cryptands
Authors: Yi Guoliang , Bradshaw Jerald S. , Krakowiak Krzysztof E. , Huang Mingxian , Lee Milton L. 
Published: March 2009

AbstractThe synthesis of two N‐(2‐allyloxy)ethyl‐substituted diaza‐crowns and two C‐pivot (allyloxy)methyl‐substi‐tuted cryptands is described. Controlled etherization of N,N‐bis(2‐hydroxyethyl)‐4,13‐diaza‐18‐crown‐6 with allyl bromide and sodium hydride gave N‐(2‐allyloxy)ethyl‐N‐(2‐hydroxyethyl)‐4,13‐diaza‐18‐crown‐6 in a good yield. This macrocycle was reacted with sodium hydride and tetrahydrofurfuryl chloride or 3,3‐dimeth‐ylbutyl tosylate to give expected N‐(2‐allyloxy)ethyl‐N'‐tetrahydrofurfuryloxy)ethyl‐[or (3,3‐dimethylbutoxy)‐ethyl]‐substituted products 3 or 4. 6,13‐Dimethylenyl‐14‐crown‐4 (9) and 9,19‐dimethylenyl‐20‐crown‐6 (10) were treated with mercuric acetate, followed by sodium borohydride in strong base to give macrocyclic diols 11 and 12, respectively. These diols were reacted with sodium hydride and the ditosylate derivative of allyloxymethyl‐substituted triethyleneglycol 13 to produce the C‐pivot (allyloxy)methyl‐substituted macrotri‐cycles 6 and 7.
A highly selective hydrogen‐deuterium exchange in indolium heptamethine cyanines
Authors: Lipowska Malgorzata , Patterson Steven E. , Patonay Gabor , Strekowski Lucjan 
Published: March 2009

AbstractChemical shift assignments in 1H nmr spectra of four tricarbocyanines have been made. Studies by 1H nmr have shown a rapid acid‐catalyzed proton exchange at positions 1′,7′ and a much slower exchange at positions 3′,5′ of the heptamethine chain. Base catalysis results in a slow exchange at positions 1′,7′ only.
Efficient synthesis of azetidine through N‐trityl‐ or N‐dimethoxytritylazetidines starting from 3‐amino‐l‐propanol or 3‐halopropylamine hydrohalides
Authors: Huszthy Peter , Bradshaw Jerald S. , Krakowiak Krzysztof E. , Wang Tingmin , Dalley N. Kent 
Published: March 2009

AbstractEfficient synthetic routes for the preparation of azetidine starting from commercially available 3‐amino‐l‐propanol or 3‐halopropylamine hydrohalides are reported. First, the appropriate N‐trityl‐ or N‐dimethoxy‐trityl protected tosyloxy‐ or halopropylamines were prepared. These precursors were then cyclized into the N‐trityl‐ or N‐dimethoxytritylazetidines. The N‐protecting groups were removed in the presence of perchloric acid giving the hydrogen perchlorate salt of azetidine. The latter compound was transformed into its free base using a strong base under anhydrous conditions. The relatively expensive 4,4′‐dimethoxytrityl chloride and less expensive trityl chloride used in these synthetic procedures were recycled in good yields. Azetidine hydrogenperchlorate can be used to prepare N‐substituted azetidines without the need to isolate the free azetidine.
Synthesis and antiviral evaluation of β‐L‐Xylo‐fuanosyl nucleosides of the five naturally occurring nucleic acid bases
Authors: Gosselin Gilles , Bergogne Marie‐Christine , Imbach Jean‐Louis 
Published: March 2009

AbstractThe β‐L‐xylo‐furanosyl analogues of the naturally occurring nucleosides have been synthesized and their antiviral properties examined. All these compounds were hitherto unknown and they were stereospecifically prepared by glycosylation of pyrimidine and purine aglycons with a suitably peracyl‐L‐xylo‐furanose (specially synthesized from L‐xylose for our present purpose), followed by removal of the protecting groups. All the prepared compounds were tested for their activity against a variety of DNA and RNA viruses (including HIV), but they did not show significant antiviral activity.
Synthesis of 1‐(N‐arylaminomethyl)‐3‐methyl‐1,8‐dihydrocycloheptapyrazol‐8‐ones
Authors: Piao Ming‐Zhu , Wang Dao‐Lin , Lu Du‐Ren , Imafuku Kimiaki 
Published: March 2009

AbstractReactions of 3‐methyl‐1,8‐dihydrocycloheptapyrazol‐8‐one (2) with arylamines in the presence of formaldehyde gave 1‐(N‐arylaminomethyl)‐3‐methyl‐1,8‐dihydrocycloheptapyrazol‐8‐ones 5a‐l in good yields. 1,3,5‐Tris(phenyl‐ and 4‐methoxyphenyl)hexahydro‐1,3,5‐triazines or bis(3‐nitroanilino)methane, which were condensation products of arylamines and formaldehyde, also reacted with compound 2 to afford 5a,c,j, respectively.
Synthesis of 2‐carbamoylmethyl‐6‐β‐D‐ribofuranosylpyridine with the aid of a Pd(0)‐catalyzed reaction
Authors: De Vos Eric , Esmans Eddy L. , Alderweireldt Frank C. , Balzarini Jan , De Clercq Erik 
Published: March 2009

AbstractD‐Allo/D‐altro‐2‐(2,4:3,5‐di‐O‐benzylidenepentitol‐l‐yl)‐6‐ethoxycarbonylmethylpyridine was synthesized from 2‐bromo‐6‐(2,4:3,5‐di‐O‐benzylidenepentitol‐1‐yl)pyridine or 2‐(2,4:3,5‐di‐O‐benzylidenepentitol‐1‐yl)‐6‐iodopyridine by means of a tetrakis(triphenylphosphine)palladium(O)‐catalyzed reaction with Reformatsky's reagent. Subsequent ammonolysis and mesylation of the D‐altro‐ethoxycarbonylmethyl compound gave D‐altro‐2‐carbamoylmethyl‐6‐(1‐O‐mesyl‐2,4:3,5‐di‐O‐benzylidenepentitol‐l‐yl)pyridine which was cyclized to 2‐carbamoylmethyl‐6‐β‐D‐ribofuranosylpyridine.
Synthesis and conformational properties of 2′‐deoxy‐2′‐methylthio‐pyrimidine and ‐purine nucleosides: Potential antisense applications
Authors: Fraser Allister , Wheeler Patrick , Dan Cook P. , Sanghvi Yogesh S. 
Published: March 2009

AbstractA convenient and shorter synthesis of 2′‐deoxy‐2′‐methylthiouridine analogs 5, −5‐methyluridine 6, ‐cyti‐dine 15, −5‐methylcytidine 16, ‐adenosine 27 and ‐guanosine 34 was accomplished. Successful conversion of ribonucleosides (5‐methyl U, U, A, G) into the corresponding 2′‐substituted nucleosides involves nucleophilic displacement (SN2) of an appropriate leaving group at the 2′‐position by methanethiol, a soft nucleophile. Reaction between 2,2′‐anhydrouridine and methanethiol in the presence of N1,N1,N3,N3‐tetramethylguani‐dine in N,N‐dimethylformamide gave 5, in 75% yield. Preparation of 6 by a similar route was described. Acylated 5 and 6 were transformed into their triazole derivatives, which on ammonolysis furnished 15 and 16, respectively in good yield. Similarly, tetraisopropyldisiloxanyl (TIPS) protected 2′‐O‐aratriflates‐ of‐adenosine and ‐guanosine reacted with methanethiol in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene at ‐ 25°, followed by deblocking of the TIPS protecting group furnished 27 and 34, respectively. The confor‐mational flexibility (N/S equilibrium) of the sugar moiety in nucleosides 5, 15, 27 and 34 was studied utilizing nmr spectroscopy, suggesting that the 2′‐methylthio group influenced the sugar conformation to adopt a rigid S‐pucker in all cases. The extra stiffness of the sugar moiety in these analogs is believed to be due to the electronegativity of the substituent and the steric bulk. The usefulness of these nucleosides to prepare uniformly modified 2′‐deoxy‐2′‐methylthio oligonucleotides for antisense therapeutics is proposed.
Synthesis and antiviral evaluation of some novel [1,2,4]triazolo[4,3‐β][1,2,4]triazole nucleoside analogs
Authors: Jois Y. H. R. , Kwong C. D. , Riordan J. M. , Montgomery J. A. , Secrist J. A. 
Published: March 2009

AbstractRibosylation of 3‐amino‐5H‐[1,2,4]triazolo[4,3‐b][1,2,4]triazole (1) with l‐O‐acetyl‐2,3,5‐tri‐O‐benzoyl‐D‐ribofuranose and stannic chloride resulted in the following protected nucleoside analogs: 3‐amino‐1‐(2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranosyl)[1,2,4]triazolo[4,3‐β][1,2,4]triazole (4), 3‐amino‐1‐(2,3,5‐tri‐O‐benzoyl‐α‐D‐ribofuranosyl)[1,2,4]triazolo[4,3‐β][1,2,4]triazole (5), 3‐amino‐1‐(2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranosyl)[1,2,4]triazolo[4,3‐β][1,2,4]triazole (5), and 3‐(2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranosyl) amino‐5H‐[1,2,4]triazolo[4,3‐b]‐[1,2,4]triazole (7). Compounds 4–6 were deprotected to 3‐amino‐1‐β‐D‐ribofuranosyl[1,2,4]triazolo[4,3‐b][1,2,4]‐triazole (3), 3‐amino‐1‐α‐D‐ribofuranosyl[1,2,4]triazolo[4,5‐b][1,2,4]triazole (8), and 3‐imino‐2H‐2‐β‐D‐ribo‐furanosyl[1,2,4]triazolo[4,3‐b][1,2,4]triazole (9), while 7 could not be deprotected without decomposition. Compounds 1, 4, 6, 7, and 9 were screened and found to have no antiviral activity.