bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intermolecular 1,3‐dipolar cycloaddition of benzonitrile oxide to 2H‐1,3‐benzothiazines and hexahydro‐4H‐1,3‐benzothiazine
Authors: Szabó János , Fodor Lajos , Bernáth Gábor , Talpas Gizella S. , Bani‐Akoto Ernest , Sohár Pál 
Published: March 2009

AbstractThe thermal [3 + 2] intermolecular cycloaddition of benzonitrile oxide to 2H‐1,3‐benzothiazines 1a‐g and hexahydro‐4H‐1,3‐benzothiazine (5) gives new types of tricyclic angularly and linearly condensed 1,2,4‐oxadiazolo‐1,3‐benzothiazine‐fused nitrogen‐bridgehead ring systems 2a‐g, 6.
An anomalous reaction of 7‐chloro‐2‐hydrazono‐5‐phenyl‐1,2‐dihydro‐3H‐1,4‐benzodiazepine with sodium acetate and 1,1′‐carbonyldiimidazole
Authors: Banks William R. , Hawi Amale A. , Digenis George A. 
Published: March 2009

AbstractThe addition of 7‐chloro‐2‐hydrazono‐5‐phenyl‐1,2‐dihydro‐3H‐1,4‐benzodiazepine 3 to a mixture of sodium acetate and 1,1′‐carbonyldiimidazole 1 at room temperature gave, in moderate yields, carbonyl‐1,1′‐bis[7‐chloro‐5‐phenyl‐1,2‐dihydro‐3H‐1,4‐benzodiazepin‐2‐ylidene hydrazone] 7 instead of the expected 2‐acetylhydrazono‐7‐chloro‐5‐phenyl‐1,2‐dihydro‐3H‐1,4‐benzodiazepine 4.
Cycloaddition von benzothiet an oxime, oximether und oximester
Authors: Meier Herbert , Saul Klaus , Mengel Rudolf , Niedermann Hans‐Peter 
Published: March 2009

AbstractBenzothiete 1 generates by thermal ring opening an 8π electron system 2 which undergoes [8π + 2π] cycloaddition reactions with the oxime systems 3a‐g. In accordance with the FMO theory the 1,3‐thiazine derivatives 4a‐g are formed in a regiospecific and 4f additionally in a stereospecific manner. The O‐acylated adducts 4h‐j enter the same cycloaddition; however, an elimination reaction 4 ← 5, 6 can provoke the addition of a second benzothiete, yielding the tetracyclic compounds 7j, and 8i,j.
Studies on silyl furans. II. Halodesilylation of 2‐trimethylsilyl‐3,4‐bis(methoxycarbonyl)furans
Authors: Nakayama Koukji , Harigaya Yoshiharu , Okamoto Hiroshi , Tanaka Akira 
Published: March 2009

AbstractReactions of 2‐trimethylsilyl‐3,4‐bis(methoxycarbonyl)furans 1a,b with sulfuryl chloride, bromine, and iodine monochloride in acetonitrile afforded the corresponding 2‐halo‐3,4‐bis(methoxycarbonyl)furans 2a‐f via chloro‐, bromo‐, and iododesilylation in good yields, respectively. However, the reaction of 1a with bromine in carbon tetrachloride mainly gave 2‐bromo‐ 2b and 2‐bromo‐5‐trimethylsilyl‐3,4‐bis(methoxycarbonyl)furan (3) in 37% and 45% yields. Similarly, the reaction of 1a with iodine monochloride afforded 1a, 2‐chloro‐ 2a and 2‐iodo‐3,4‐bis(methoxycarbonyl)furan (2c) in 50%, 27%, and 23% yield.
Stereochemistry of cycloadducts from 3,4‐dihydro‐6,7‐dimethoxyisoquinoline ylide and olefins
Authors: Janke Frank , Himmelreich Uwe , Tóth Gábor , Tischer Thomas , Kádas István , Bende Zoltán , Töke László 
Published: March 2009

AbstractCycloaddition of 2‐methoxycarbonylmethyl‐3,4‐dihydro‐6,7‐dimethoxyisoquinolinium ylide with various E‐substituted olefin type dipolarophiles gave products of 10b‐H, 1‐H, 2‐H and 3‐H α,α,β,β‐relative configuration with one exception. Relative configuration of compounds prepared has been determined by 1D and 2D 1H and 13C nmr techniques. It has also been detected that a triple trans ⇌ cis‐1 ⇌ cis‐2 conformation equilibrium exists in solution.
Reaction of α,β‐unsaturated carbodiimides with enamines leading to fused pyridine derivatives
Authors: Noguchi Michihiko , Onimura Kenjiro , Isomura Yuji , Kajigaeshi Shoji 
Published: March 2009

AbstractThe treatment of (5,5‐dimethyl‐3‐oxo‐1‐cyclohexenyl)iminotriphenylphosphorane (2) with phenyl isocyanate (3a) gave N‐(5,5‐dimethyl‐3‐oxo‐1‐cyclohexenyl)‐N'‐phenylcarbodiimide (4a) in situ. The reaction of 4a with enamines proceeded smoothly to afford the pyridine ring formation with the elimination of amine. This means that 4a is regarded as a new class of 2‐aza‐1,3‐butadiene. The scopes and limitation of this reaction are also discussed.
Syntheses of tetraoxaquaterene derivatives
Authors: Tanaka Sanae , Tomokuni Hidehiko 
Published: March 2009

AbstractSeveral new dimethyl and tetramethyl tetraoxaquaterenes, 3d and 3e, have been prepared in order to synthesize the oxygen analogues of porphyrin. The reaction between furan and a ketone using an acidic catalyst gave the cyclic tetramer, tetraquaterene, and oligomers. On the other hand, in the case of furan and an aldehyde, only linear oligomers were isolated. The condensation of furan‐containing dimers with carbonyl compounds, both ketone and aldehyde, except formaldehyde, gave the tetraoxaquaterene. In the case of formaldehyde, the yield of cyclic tetramer was negligible.
Sulfenylation of some pyrroles and indoles
Authors: Gilow Helmuth M. , Brown Christopher S. , Copeland John N. , Kelly Keith E. 
Published: March 2009

AbstractMethylsulfenylation of 1‐substituted pyrroles and indoles was observed using 1‐(methylthio)morpholine and an acid catalyst or with methylsulfenyl chloride and excess pyridine. 1‐Substituents which are activating or weakly deactivating towards electrophilic substitution such as alkyl, 2‐cyanoethyl, dimethylamino, trialkylsilyl, 2‐chloroethyl and 2‐phenylsulfonylethyl were used. The 2‐chloroethyl and 2‐phenylsulfonylethyl groups which can be removed with a strong base can be used to obtain 1H‐methylthiopyrroles and indoles. 1‐Phenylsulfonyl and 1‐acetyl substituents are too strongly deactivating for these sulfenylations to be successful. Mono and disubstituted pyrroles and monosubstituted indoles can be isolated from these reactions, however, because the methylthio group is activating towards electrophilic substitution the main advantage of these reactions is the synthesis of tri and tetrasubstituted pyrroles and disubstituted indoles. 1‐Methyl‐2,3,4,5‐tetra‐methylthiopyrrole and 1‐methyl‐2,3‐dimethylthioindole are oxidized to the corresponding 3,4‐disulfoxide and 3‐sulfoxide and with excess oxidizing agent to the tetrasulfone and disulfone, respectively.
Regioselectivity in SNH reactions of some 3‐nitro‐1,8‐naphthyridines with chloromethyl phenyl sulfone
Authors: Grzegozek Maria , Woźniak Marian , Barański Andrzej , Van Der Plas Henk C. 
Published: March 2009

AbstractA number of 2‐X‐3‐nitro‐1,8‐naphthyridines (X= H,D,OH,Cl,NH2, OEt) react with the anion of chloromethyl phenyl sulfone exclusively into 2‐X‐3‐nitro‐4‐(phenylsulfonylmethyl)‐1,8‐naphthyridines in high yield. The reaction is found by quantum chemical calculations to be controlled by the interactions of the HOMO of the nucleophile with the LUMO of the substrate, and not by charge.
Studies on the reaction of 2‐aminoacetophenone with thiophosgene
Authors: Morgenstern Olaf , Richter Peter , Rouvinen Juha , Mälkönen Pentti J. , Vainiotalo Pirjo , Hänninen Kari , Ahlgrén Markku , Vepsäläinen Jouko 
Published: March 2009

AbstractThe reaction of 3‐ and 4‐aminoacetophenone with thiophosgene in a chloroform‐water‐calcium carbonate mixture at room temperature results in good yields of the related, known isothiocyanates. At first, however, we failed in all our attempts to produce 2‐isothiocyanatoacetophenones with this reaction. Closer inspection of the reaction showed, that the product distribution depends upon the concentration of hydrogen ions pro‐ducted and on the reaction time. When the reaction was followed with thin‐layer chromatography, it was observed that the isothiocyanates formed first. In the further course of the reaction, they were converted to the 4‐methylene‐2‐oxo‐3,1‐benzothiazines by the action of protons. The final products of the reaction were the 4‐(3,1‐benzothiazin‐4‐yl)‐methylene‐3,1‐benzothiazines, formed from the monomer in a dimerization process. Depending upon the time the protons were removed from the reaction mixture, different products could be isolated.
Some novel S‐mono‐ and S,S'‐unsymmetrical di‐substituted derivatives of 1,3,4‐thiadiazoledithione
Authors: Katritzky Alan R. , Borowiecka J. , Fan Wei‐Qiang , Brannigan Lawrence H. 
Published: March 2009

AbstractPreparations of S‐mono‐ and unsymmetrical S,S‐di‐substituted derivatives of 1,3,4‐thiadiazole‐2,5‐dithione are described.
Studies on pyrrolidones. Convenient syntheses of methyl, methylN‐methyl‐ and methylN‐methoxymethylpyroglutamate
Authors: Cauliez Pascal , Rigo Benoǐt , Fasseur Dominique , Couturier Daniel 
Published: March 2009

AbstractFacile methods to prepare methyl pyroglutamate (2), methylN‐methylpyroglutamate (1) and methylN‐methoxymethylpyroglutamate (7) inone‐stepfrom pyroglutamic acid are described.
Synthesis and binding activity of 4‐azanicotine
Authors: Howell Amy R. , Martin W. R. , Sloan J. W. , Smith Walter T. 
Published: March 2009

Abstract4‐Azanicotine (1) has been synthesized by the cyclopropylimine rearrangement. A study of several Lewis acids as possible catalysts for the NMF‐mediated cyclopropyl imine rearrangement of cyclopropyl‐2‐pyrazinylmethanone (4) indicated that both aluminum chloride and magnesium chloride are suitable catalysts, lithium bromide shows only a trace of activity and zinc chloride, titanium tetrachloride, and titanium tetra‐isopropoxide show no activity. Compound 1, in which the aromatic ring is less basic than in nicotine, and 6‐aminonicotine (5), in which the aromatic ring is more basic, have been compared with the binding properties of nicotine in the P2 rat brain preparation. Compound 1 binds with an affinity very similar to that of nicotine at two of the receptor sites, 5 binds at these sites but with a lower affinity. Unlike nicotine, 1 and 5 do not bind at the very high affinity ‘upregulatory’ site.
Synthesis of 2‐ and 4‐substituted 5,12‐dihydroxy‐6,11‐dioxo‐1‐azanaphthacenes from 2‐aminoquinizarine
Authors: Chauhan S. M. S. , Gupta Mamta , Nizar P. N. H. 
Published: March 2009

AbstractThe reaction of 2‐aminoquinizarine with α,β‐unsaturated carbonyl compounds in presence of 10N‐hydrochloric acid gives 2‐ and 4‐substituted 5,12‐dihydroxy‐6,11‐dioxo‐1‐azanaphthacenes.
Ring transformations of heterocycles. Part 1. Transformation of 4‐amino‐Δ2‐1,2,4‐oxadiazolines into 1,3,4‐oxadiazoles
Authors: El‐Abadelah M. M. , Nazer M. Z. , Hussein A. Q. , Awadallah A. M. , Rademacher P. , Woydt M. 
Published: March 2009

Abstract3‐Aryl‐4‐amino‐δ2‐1,2,4‐oxadiazolines 3 and their N‐chloroacetyl derivatives 4, upon treatment with chloroacetic anhydride in refluxing toluene, afford 2‐chloromethyl‐5‐aryl‐1,3,4‐oxadiazoles 5, suggesting the conversion sequence 3 → 4 → 5. The generality of the new ring transformation 4 → 5 is supported similar conversion of other 4‐(acylamino)‐1,2,4‐oxadiazolines 8 to 1,3,4‐oxadiazoles 9.
New peptide synthesis using the ozonolysate of 2‐(1‐phthalimido)alkyl‐5‐phenyloxazoles
Authors: Kashima Choji , Okada Rieko , Arao Hideki 
Published: March 2009

AbstractIt was proved that 2‐(1‐phthalimido)alkyl‐5‐phenyloxazoles 3 were useful synthetic intermediates for peptide synthesis, where the oxazole ring acted as not only the carboxyl protecting group but also the carboxyl activating group upon ozonolysis.
Action of (2‐benzothiazolyl) methyllithium with organic polar functions
Authors: Costa Maria Virginia , Brembilla Alain , Roizard Denis , Lochon Pierre 
Published: March 2009

Abstract(2‐Benzothiazolyl) methyllithium reacts quickly at low temperature (‐78°) with a variety of organic electrophiles like aldehydes, ketones, carboxylic esters, nitriles and acylchlorides. Such reactions lead to an easy introduction of alcohol, keto‐enol or amine‐enamine functional groups in extracyclic position with a stereoselective preference. These polyfunctional compounds whose synthesis is difficult by other pathways, are interesting, in particular, because of their ability to form intramolecular hydrogen bonds.
Side‐chain chlorination of methylquinolines
Authors: Kóródi Ferenc 
Published: March 2009

AbstractMethylquinolines 1–4 were chlorinated by heating with phosphorus pentachloride in chlorobenzenes to side‐chain halogen derivatives 5–14. Methyl groups of compounds 1–4 can be chlorinated to chloromethyl, dichloromethyl or trichloromethyl groups depending on their positions and the reaction conditions.
A macrocyclic amide from dehydrochlorination of indole‐3‐carbonyl chloride
Authors: Oliver J. E. , Waters R. M. , Lusby W. R. , Flippen‐Anderson J. L. 
Published: March 2009

AbstractIndolyl‐3‐ketene 3 was generated from two precursors and was found to form a symmetrical tetramer 4 consisting of a sixteen‐membered ring amide. The tetramer was characterized by mass spectrometry, infrared, 1H and 13C‐nmr spectroscopy, and single crystal X‐ray crystallography.
Unexpected chlorination products as a result of self‐diazotization of three amino‐dinitro‐2,3,4,5‐tetrahydrobenzo[b][1,4]dioxocin Derivatives
Authors: Takakis Ioannis M. , Hadjimihalakis Phaedon M. 
Published: March 2009

AbstractDiazotization of the dinitroaryl amines 1 with nitrous acid (generated from hydrochloric acid and sodium nitrite) furnished the unexpected chloronitro azides 3 as a result of self‐diazotization. Subsequent heating of 3 in ethylene glycol afforded the corresponding chloro‐nitro amines 5 and/or the deaminated products 4. Some mechanistic aspects of these transformations are discussed.
Synthesis of 4H‐1,4‐benzothiazine 1‐oxide and 1,1‐dioxide. Analogs of quinolone antibacterial agents
Authors: Culbertson Townley P. 
Published: March 2009

Abstract4‐Cyclopropyl‐5,7‐difluoro‐6‐(4‐methyl‐1‐piperazinyl)‐4H‐1,4‐benzothiazine‐2‐carboxylic acid 1‐oxide (2c) and 4‐cyclopropyl‐5,7‐difluoro‐6‐(4‐methyl‐1‐piperazinyl)‐4H‐1,4‐benzothiazine‐2‐carboxylic acid 1,1‐dioxide (2d) were prepared and assayed for antibacterial activity and inhibition of DNA gyrase.
Synthesis of (R)‐1,2,11‐trihydroxy‐, (R)‐2,11‐, and (R)‐2,10‐dihydroxyaporphines — non naturally occurring aporphine alkaloids from pukateine and thebaine
Authors: Ram Vishnu J. , Neumeyer John L. 
Published: March 2009

AbstractThe synthesis of (R)‐2,10‐dihydroxyaporphine (3a), (R)‐2,10‐dihydroxy‐N‐n‐propylnoraporphine (3b) from thebaine and (R)‐2,11‐dihydroxyaporphine (7), and 1,2,11‐trihydroxyaporphine (9), from pukateine is reported. The rearrangement of thebaine and northebaine with methanesulfonic acid to 1a and 1b with subsequent N‐propylation gave 1b. Tetrazolyation of 1a, 1b and hydrogenolysis of 2a and 2b on Pd/C in acetic acid with subsequent O‐demethylation with hydrobromic acid (48%) led to 3a and 3b. R(‐)‐2,11‐Dihydroxyaporphine (7) was prepared by lithium/ammonia reduction of pukateine. (R)‐1,2,11‐Trihydroxyaporphine (9) was synthesized by reaction of pukateine with boron tribromide in dichloromethane.
Synthesis and properties of thiolactam analogs of pyrromethenones
Authors: Xie Meiqiang , Lightner David A. 
Published: March 2009

AbstractThiolactam analogs of kryptopyrromethenone and xanthobilirubic acid methyl ester were prepared from the parent pyrromethenone using Lawesson's reagent and are shown to form dimeric association complexes through intermolecular hydrogen bonding.
Deprotonations of 5‐nitroindole and 5‐nitroindole‐2‐carboxylate ion in zwitterionic surfactants
Authors: Cipiciani Antonio , Primieri Stefania 
Published: March 2009

AbstractDeprotonations of 5‐nitroindole (1) and its 2‐carboxylate ion 2 at high pH have been examined in solutions of N,N‐dimethyl‐N‐tetradecylglycine (DTG) and N,N‐dimethyl‐N‐hexadecylglycine (DHG). We have compared the surfactant effects with those of single‐ and twin‐tailed ionic surfactants.
Synthesis of 6‐(4‐methyl‐1‐piperazinyl)‐7H‐indeno[2,1‐c]‐quinoline derivatives as potential 5‐HT receptor ligands
Authors: Anzini M. , Cappelli A. , Vomero S. 
Published: March 2009

AbstractTwo synthetic pathways for the achievement of the title compounds are reported. The key intermediate, namely 3‐carboxy‐4‐phenyl‐2(1H)‐quinolinone 9, was directly cyclized into the corresponding 6‐chloro‐7H‐indeno[2,1‐c]quinolin‐7‐one 10 or alternatively it was esterified, reduced to the alcohol, chlorinated and cyclized into the 6‐chloro‐7H‐indeno[2,1‐c]quinoline 8. Further reaction of the chloroindenoquinoline derivatives with N‐methylpiperazine afforded the piperazinyl derivatives 4a‐c.
Directed metalation of pyridinesulphonamides. Synthesis of pyridine‐fused isothiazoles and 1,2‐oxathioles
Authors: Alo Babajide I. , Familoni Oluwole B. , Marsais Francis , Queguiner Guy 
Published: March 2009

Abstract4‐Lithio‐N‐t‐butylpyridine‐3‐sulphonamide reacted with benzophenone and carbon dioxide respectively to give the corresponding intermediates which on appropriate treatment gave isothiazolo[5,4‐c]pyridin‐3‐one 1,1‐dioxides. Metalation of 2‐ and 4‐(N,N‐dialkylaminosulphonyl)pyridines with lithium diisopropylamide (LDA) gave anions which reacted with benzophenone to give carbinols which thermally cyclised to 1,2‐oxathiolo[3,4‐b]pyridine and 1,2‐oxathiolo[4,3‐c]pyridine respectively.
Synthesis of selenobispyridines
Authors: Dunne Simon J. , Summers Lindsay A. , Von Nagy‐Felsobuki Ellak I. 
Published: March 2009

Abstract2,3′‐Selenobispyridine, 2,4′‐selenobispyridine, 3,3′‐selenobispyridine and 3,4′‐selenobispyridine have been synthesised.
Photochemical cyclization of some aldehyde thiosemicarbazones
Authors: Gruttadauria Michelangelo , Buccheri Francesco , Buscemi Silvestre , Cusmano Giuseppe , Noto Renato , Werber Giuseppe 
Published: March 2009

AbstractThe photochemical behaviour of some substituted aldehyde thiosemicarbazones 1a‐k has been investigated in methanol at 254 nm. Thiosemicarbazones of glyoxil methyl ester 1a‐f cyclized to furnish the 3‐thioxo‐ 1,2,4‐triazin‐5‐one 2 ring system. The remaining thiosemicarbazones 1g‐j gave 1,2,4‐triazoline 4 derivatives.
1‐Methylimidazolium chlorochromate: A new Cr(VI) oxidant and use of anhydrous acetic acid as the catalyst for the oxidation of primary and secondary alcohols
Authors: Agarwal Seema , Tiwari H. P. , Sharma J. P. 
Published: March 2009

AbstractThe synthetic potential of a new Cr(VI) reagent, viz., 1‐methylimidazolium chlorochromate, analogous to Corey's reagent‐PCC, has been examined. Anhydrous acetic acid has been found to catalyze the oxidation reaction.
Carbon‐nitrogen bond formation in cyclisation by deoxygenation, thermolysis or photolysis of phenylimidazo[1,2‐a][1,8]naphthyridines
Authors: Gueiffier A. , Blache Y. , Viols H. , Chapat J. P. , Chavignon O. , Teulade J. C. , Dauphin G. , Debouzy J. C. , Chabard J. L. 
Published: March 2009

AbstractTriethyl phosphite deoxygenation of 2‐(2‐nitrophenyl)imidazo[1,2‐a][1,8]naphthyridine (3) led to the C‐insertion to give the indoloimidazonaphthyridine 5. Our attempt to promote the N‐insertion by blocking the C‐3 position failed. Triethyl phosphite deoxygenation of 1‐nitroso‐2‐(4‐fluorophenyl)imidazo[1,2‐a][1,8]‐naphthyridine (12) led to the corresponding amine structure (15). Thermolysis and photolysis of 6,8‐dimethyl‐2‐(2‐azidophenyl)imidazo[1,2‐a][1,8]naphthyridine (17) are also reported.
The crystal structure of 1,5‐bis(3,5‐dimethyl‐2‐hydroxybenzyl)‐1,5‐diazocan‐2,6‐dione
Authors: Aversaw M. C. , Bonaccorsi P. , Giannetto P. , Beagley B. , Leigh D. A. , Pritchard R. , Truscello A. M. 
Published: March 2009

AbstractThe study of the molecular geometry of 1,5‐bis(3,5‐dimethyl‐2‐hydroxybenzyl)‐1,5‐diazocan‐2,6‐dione (2) as determined by X‐ray analysis is reported and compared with that of cyclodi‐β‐alanyl (3). Interestingly there are 1.5 molecules of 2 in the asymmetric unit, showing the two conformations (1 twist‐boat‐ and 0.5 chair‐type) with two parallel aromatic rings (from alternate twist‐boat conformers) sandwiching the eight‐membered ring of the centrosymmetric chair‐type conformation. The twist‐boat is shown by pmr spectroscopy to be the only significantly populated conformer at low temperature in deuteriodichloromethane solution.
Synthesis of 5,7‐disubstituted‐4‐β‐D‐ribofuranosylpyrazolo[4,3‐d]‐pyrimidines and 2,4‐disubstituted‐1‐β‐D‐ribofuranosylpyrrolo[3,2‐d]‐pyrimidines as congeners of uridine and cytidine
Authors: Sudhakar Rao T. , Revankar Ganapathi R. , Vinayak Ravi S. , Robins Roland K. 
Published: March 2009

AbstractThe synthesis of the congeners of uridine and cytidine in the pyrazolo[4,3‐d]pyrimidine and pyrrolo[3,2‐d]‐pyrimidine ring system is described. Glycosylation of the trimethylsilyl (TMS) derivative of pyrazolo[4,3‐d)pyrimidine‐5,7(1H,4H,6H)‐dione (4) with either 1‐bromo‐ or 1‐O‐acetyl‐2,3,5‐tri‐O‐benzoyl‐D‐ribofuranose 5 and 6, respectively in the presence of a Lewis acid catalyst gave the protected nucleoside 7, which on debenzoylation afforded the uridine analogue 4‐β‐D‐ribofuranosylpyrazolo[4,3‐d]pyrimidine‐5,7(1H,6H)‐dione (8). Thiation of 7 gave 13, which on deprotection yielded 4‐β‐D‐ribofuranosyl‐5‐oxopyrazolo[4,3‐d]pyrimidine‐7(1H,‐6H)‐thione (14). Ammonolysis of 13 gave a low yield of the cytidine analogue 15. A chlorination of 7, followed by amination furnished an alternative route to 15. A similar glycosylation of TMS‐4 with 2,3,5‐tri‐O‐benzyl‐α‐D‐arabinofuranosyl chloride (16) gave mainly the N4 glycosylated product 17, which on debenzylation furnished 4‐β‐D‐arabinofuranosylpyrazolo[4,3‐d]pyrimidine‐5,7(1H,6H)‐dione (18). 7‐Amino‐4‐β‐D‐arabinofuranosylpyrazolo[4,3‐d]pyrimidin‐5(1H)‐one (23) was prepared from 17 via the pyridinium chloride intermediate 21. Condensation of the TMS derivative of pyrrolo[3,2‐d]pyrimidine‐2,4(1H,3H,5H)‐dione (24) with 6, followed by deprotection of the reaction product gave 1‐β‐D‐ribofuranosylpyrrolo[3,2‐d]pyrimidine‐2,4(3H,5H)‐dione (26). Similarly, TMS‐24 was reacted with 16 to give a mixture of the blocked nucleosides 31 and 32, which on debenzylation afforded a mixture of two isomeric compounds 34 and 35. 1‐β‐D‐Arabinofuranosylpyrrolo[3,2‐d]pyrimidine‐2,4(3H,5H)‐dione (34) was converted to the ara‐C analogue 38 via the 3‐nitrotriazolyl intermediate 36. The structure of 38 was confirmed by single crystal X‐ray diffraction studies.
Nucleocyclitols. Synthesis of substituted purinyl‐muco‐inositol derivatives
Authors: Aguilar Guillermo J. , Gelpi María E. , Cadenas Raúl A. 
Published: March 2009

AbstractSeveral carbocyclic nucleoside analogs possessing a 6‐substituted purine linked to a mesylated muco‐inositol were synthesized. The coupling of triethylamine‐activated 6‐chloropurine with 2,3‐anhydro‐l,5,6‐tri‐O‐(methanesulfonyl)‐epi‐inositol gave a 6‐chloro purinyl muco‐inositol amenable to further synthetic transformations in the heterocyclic moiety by substitution of the chlorine atom by nitrogen nucleophiles such as methylamino, diethylamino, benzylamino, hydrazino, morpholino, hydroxylamino, piperidino, and glycyl groups.
Furan derivatives. Part 13. Synthesis of thiopyrano[4,3,2‐cd]benzofuran
Authors: Horaguchi Takaaki , Hasegawa Kohei , Hasegawa Eietsu , Shimizu Takahachi , Tanemura Kiyoshi , Suzuki Tsuneo 
Published: March 2009

AbstractThiopyrano[4,3,2‐cd]benzofuran 9 possessing benzofuran and methylenethiopyran structures in the molecule was synthesized starting from 1‐chloro‐4‐methoxy‐2‐nitrobenzene 11. Some reactions (formylation, protonation and catalytic hydrogenation) on 9 were examined. The 2‐position of 9 was highly reactive toward electrophilic reagents and the furan ring was readily reduced by catalytic hydrogenation with palladium‐charcoal. Thiopyrano[4,3,2‐cd]benzofuran 9 has both properties of methylenethiopyran and benzofuran.
Conjugated macrocycles related to the porphyrins. Part 3. Acid catalyzed condensations of thiophenecarboxaldehydes with a dipyrrylmethane
Authors: Armiger Yoek Lin See‐Tow , Lash Timothy D. 
Published: March 2009

AbstractMacDonald condensation of a dipyrrylmethanedicarboxylic acid 3b with 2,2′‐dithienylmethane‐5,5′‐dicarboxaldehyde (2b) failed to give the expected dithiophene porphyrin analog 1b. However, oxidation of the reaction mixtures with DDQ gave trace amounts of porphyrin‐like materials. Model studies indicate that these fractions are meso‐dithienylporphyrins. The synthesis of three related α,γ‐disubstituted porphyrins is described.